The Exercise & Nutrition Scientist: The Truth About Exercising On Your Period! Women Were Right About Menopause! These 4 Supplements Give Women Optimal Health!

Is mainstream exercise advice sexist? Dr Stacy Sims reveals the science-backed secrets for optimal health and fitness every women needs Dr Stacy Sims is an exercise physiologist, nutrition scientist, and expert in female-specific nutrition and exercise. She is the author of books such as, ‘Next Level - Your Guide to Kicking Ass, Feeling Great, and Crushing Goals Through Menopause and Beyond’. In this conversation, Dr Stacy and Steven discuss topics such as, how to optimise your menstrual cycle for fitness, the biggest myths about menopause, why women need more protein than men, and the truth about creatine for women. 00:00 Intro 02:20 What Is the Work Stacey Does and Why Does She Do It? 09:52 Stacey's Academic Background 12:10 Main Physiological Differences Between Men and Women 14:35 Q-Angle 17:05 Fat Differences in Men and Women 17:48 Heart Differences in Men and Women 19:10 Lung Differences in Men and Women 20:20 Muscle-Building Capacities in Men vs. Women 20:48 ACL Injuries 22:10 What Is Quad Dominance? 23:04 How Much More Likely Are Women to Get ACL Injuries? 25:21 ACL Injury Prevention in Women 28:01 Does Science View Women as Smaller Versions of Men? 33:01 Differences in Weight Loss Advice for Men and Women 36:04 What Is the Hypothalamus? 42:46 Fasting and Exercise Differences for Women vs. Men 50:18 Stacey's Thoughts on Ozempic 52:11 When Should We Eat Around Training? 53:23 Stacey's Thoughts on Keto 54:53 Keto and the Microbiome 56:38 Saunas and Cold Plunge Differences 01:00:38 Women's Use of Creatine 01:05:53 Recommended Supplements for Women 01:11:28 Blood Glucose Sensitivity 01:15:16 Adapting Nutrition and Exercise to Your 28-Day Cycle 01:17:45 Are There Days in the Cycle We Shouldn't Work Hard? 01:20:51 When Are Women Strongest in Their Cycle? 01:21:48 Unasked Questions About the Menstrual Cycle 01:24:49 Why Is Bone Health So Important? 01:26:19 Sleep Differences Between Men and Women 01:28:05 Jet Lag Differences 01:30:12 Chronotypes 01:31:47 How Important Are Meal Timings? 01:35:30 Let's Talk About Menopause 01:41:25 The Perimenopause Phase 01:49:59 HRT (Hormone Replacement Therapy) 01:54:41 Nutrition, Exercise, and Endometriosis/PCOS 01:56:25 What Is the Most Important Thing We Haven't Talked About? 01:59:05 Why Don't We Learn About Women's Health in School? 01:59:40 The Most Important Message Stacey Would Pass On to Her Kids Follow Dr Stacy: Instagram - https://bit.ly/4j10BhK YouTube - https://bit.ly/41WFZAY Website - https://bit.ly/4a8xB3C You can purchase Dr Stacy’s book, ‘Next Level - Your Guide to Kicking Ass, Feeling Great, and Crushing Goals Through Menopause and Beyond’, here: https://amzn.to/4a4gYGk Watch the episodes on Youtube - https://g2ul0.app.link/DOACEpisodes My new book! 'The 33 Laws Of Business & Life' is out now - https://g2ul0.app.link/DOACBook You can purchase the The Diary Of A CEO Conversation Cards: Second Edition, here: https://g2ul0.app.link/f31dsUttKKb Independent Fact Check: https://stacysims.tiiny.co Follow me: https://g2ul0.app.link/gnGqL4IsKKb Sponsors: 1% Diary: Join the waitlist to be the first to hear about the next drop of The 1% Diary! https://bit.ly/1-Diary-Megaphone-ad-reads Shopify - https://shopify.com/bartlett ZOE - http://joinzoe.com with code BARTLETT10 for 10% off Learn more about your ad choices. Visit megaphone.fm/adchoices

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

• 0:00Dr. Stacy Sims?

  A lot of women come with their partners to see me and say, I don't understand. We're both doing the same training. He's leaning up and getting fitter. I'm putting weight on and getting slower. And that is because we have puberty, we have our reproductive years. We don't have pregnancy in there. We have perimenopause, we have postmenopause, we have menstrual cycle. Each one of those is a different hormone profile that can affect the way we eat and the way we train. But no one told us this or what we can do.

• 0:22Steven Bartlett?

  Until right now. Dr. Stacey Sims is an exercise physiologist and nutrition scientist.

• 0:27Speaker 02

  His bestselling books and over 100 peer reviewed studies is revolutionizing how women can optimize their health, fitness and longevity by working with their unique physiology.

• 0:36Dr. Stacy Sims?

  We're looking at sports science research, everything from training to eating, recovery. It's based on male data and women have been generalized to that data. Things like we see men do really well on calorie restriction and fasting. But for women, it doesn't happen that way. And we'll talk about that. And we also know that during puberty, girls hips widen, shoulders widen, which changes our angle of united hip, what we call the Q angle, so they don't feel comfortable running or swimming or jumping. And because they're not taught this stuff. We see that by the age of 14, girls who previously were sporty, over 60% of them drop out of sport. The problem is, it's never about how we can empower women to use their physiology to their advantage.

• 1:11Steven Bartlett?

  So let's change that.

• 1:13Dr. Stacy Sims?

  Let's go.

• 1:13Steven Bartlett?

  As it relates to nutrition and exercise, how do I need to adapt across the menstrual cycle? What's your view on cold plunges and supplements like creatine? And what's the variant between men and women as it relates to sleep? And then let's talk about menopause, starting with perimenopause.

• 1:26Dr. Stacy Sims?

  I'm excited.

• 1:28Speaker 03

  The diary of a CEO is independently fact checked. For any studies or science mentioned in this episode, please check the show notes.

• 1:34Steven Bartlett?

  I find it incredibly fascinating that when we look at the backend of Spotify and Apple and our audio channels, the majority of people that watch this podcast haven't yet hit the follow button or the subscribe button, wherever you're listening to this. I would like to make a deal with you. If you could do me a huge favor and hit that subscribe button, I will work tirelessly from now until forever to make the show better and better and better and better. I can't tell you how much it helps when you hit that subscribe button. The show gets bigger, which means we can expand the production, bring in all the guests you want to see and continue to do in this thing we love. If you could do me that small favor and hit the follow button, wherever you're listening to this, that would mean the world to me. That is the only favor I will ever ask you. Thank you so much for your time.

• 2:16Steven Bartlett?

  Dr. Stacey Sims.

• 2:20Steven Bartlett?

  What is the work that you do and why is it so important that you do it?

• 2:24Dr. Stacy Sims?

  I look at sex differences in exercise and nutrition because when we think about everything that we know for protocols from training to eating, recovery, it's based on male data. And as a female athlete and working with women across all ages, just trying to maximize their potential, you have to lean into different data. But people aren't aware of it. So as I'm looking at what I do and trying to empower women to understand their own bodies, realize that there's a lot of research that still needs to be done. So if we think about something like caffeine and caffeine intake, right? And people are talking about how it either boosts them or not.

• 3:05Steven Bartlett?

  Yeah.

• 3:05Dr. Stacy Sims?

  If we look at all the data on performance about caffeine enhancing performance, there isn't anything that's been done on women. So if we're looking at how does that work for a woman, we have to look and say, okay, how much exercise have you done? Where are you using caffeine? When are you using it? Because we fuel differently during exercise. We go through blood sugar quickly. Caffeine clears blood sugar. So a woman is going to have to eat when she uses caffeine, whereas a man doesn't have to.

• 3:34Steven Bartlett?

  You said it's based on male data. How can you quantify that? Like, paint the picture for me that proves this is the case, for someone that might not understand the significance of what you just said.

• 3:45Dr. Stacy Sims?

  So if we're looking at sports science research, and I'll just bring it down to sports science, because that's the exercise and nutrition research. If we're looking at who's around the room when we're recruiting for studies, for the most part, the language around recruitment is geared for getting men, because we're using a lot of aggressive language in sport. So it's off putting to a lot of women. The other aspect about sports science research is there's limited funding. So then we're looking at, okay, how can we get people in that can come in for day after day or week to week? Most often, it's men. When we look at what we're doing, we might be doing muscle biopsies, we might be doing blood draws, and if that's not explained in advance, it's a little off-putting to people.

• 4:30Dr. Stacy Sims?

  So when we're looking at the major recruitment strategies and the people that will say, yes, I'll come and do this study, it's 18 to 22-year-old, college-age men. And that's just been the norm. And when we look at how studies are designed, and we're looking again at who's in the room, who's designing the studies, primarily it's men. Why? Because we see that most of the PIs on the studies and most of the, I guess, scientists that are coming up in academia are primarily men.

• 5:00Steven Bartlett?

  When did you realize this?

• 5:02Dr. Stacy Sims?

  The first time I realized it from an academic standpoint was when I was a second year at university. And I was a participant in metabolism lab, and I was one of the only women. And I standardized properly, I did all the things I was supposed to do because I come from a military family, I know how to follow rules. And at the end of the two weeks of experiments, they threw my results out.

• 5:27Steven Bartlett?

  Why?

• 5:28Dr. Stacy Sims?

  Exactly. So I asked why. And they're like, well, your results don't jive with what we thought we were going to see. They don't mesh with the results that we got from the men, so they're an anomaly. So we're not going to put them in for the context of talking about how carbohydrate metabolism was going. And I thought that was very strange. And I was like, well, I've done everything properly, how come mine are the anomaly and those guys aren't the anomaly? How do you know that? And they didn't have an answer for it. So that was like the sticking point for me to understand, why would my results be an anomaly when I've done exactly the same thing as what the men had done? And it came down to menstrual cycle.

• 6:09Dr. Stacy Sims?

  Came down to understanding that one week I was in a low hormone state, and then the next week I wasn't. So when I started talking about that, this is where the professor who was in charge of the metabolism labs, like, well, we don't study women because they have a menstrual cycle. And we just study men because they're easier and we don't have to worry about hormone fluctuations interfering with our results. And at that point, I was like, excuse me? What? What are you talking about? So that was a defining point from an academic standpoint. But the seed had been planted two years prior when my dad, who was a Colonel in the Army, was like, so what do you want to do when you finish graduate or when you graduate from high school?

• 6:54Dr. Stacy Sims?

  And I said, I wanted to be an Army Ranger or Navy SEAL. And he said, well, you can't. And I said, well, why can't I? And he said, because you're a girl. I was like, what, what does that mean? And he said, well, they don't accept women in, in the SEALs or the Rangers. It's a special ops and they don't accept women. And that was the first time in my life I've ever heard that I was limited because I was a female and I didn't match what the norm was. So my whole life, I'd been playing with boys, competing against boys. I mean, like, it was just a normal. Didn't matter if you were a boy or a girl. It just was what you wanted to do. And then when my dad said, well, you can't because you're a girl. That was the first seed that had been planted and really made me upset and said, well, this doesn't make sense.

• 7:39Dr. Stacy Sims?

  And then when I got to university and that happened, that was the definitive seed that just really pushed me into the whole academic and sporting career that I've led over the past twenty some years.

• 7:50Steven Bartlett?

  Give me an overview of that career. The sort of significant milestones and the research that you've done that's fed into everything that you know today.

• 7:58Dr. Stacy Sims?

  I've been a competitive athlete most of my life. So I would, I raced bikes professionally. I did Ironman, I did Xterra. And I'd have teammates who would ask me questions of, you know, like, how am I fueling? How am I going to perform my best? So we'd take those questions into the lab. So we were looking at how do we optimally fuel? Or how do we optimally acclimatize the heat when we're at a point in our menstrual cycle where we don't have as much heat tolerance? So that we see when progesterone comes up after ovulation or core temperature comes up, we don't have as much heat tolerance. So how do we adjust for that? So there are a lot of questions that would come through just by the nature of being surrounded by competitive athletes and being a competitive athlete.

• 8:43Dr. Stacy Sims?

  So we look at things like, we know now that when you want to do. Acclimatization to the heat. And I bring this up because if I live in New Zealand in the wintertime and I'm trying to train for something like Kona, that happens in Hawaii, and we max out at, you know, ten degrees Celsius in the winter, but we have to face forty degrees Celsius to race Ironman. And we get into a sauna and we want to accommodate for that heat. We know that men can go seven days in a row and be fine to then race in the heat. But for women, depends on which phase of the menstrual cycle. And if you are going in the high hormone phase, then we say, okay, well, you don't need a primer.

• 9:25Dr. Stacy Sims?

  You can just go in and do nine days in a row. But if you start in the low hormone phase, you actually have to go into the sauna for five minutes, come back out, and then go back in and do that during the low hormone phase for nine days in a row. So there are different nuances in the way that your body responds to the heat and is able to accommodate for those heat shifts versus a man can just go in and accommodate for that and be ready for the race.

• 9:52Steven Bartlett?

  So give me your CV.

• 9:54Dr. Stacy Sims?

  Oh, gosh.

• 9:56Steven Bartlett?

  Not the whole thing?

• 9:57Dr. Stacy Sims?

  It's it's pretty varied.

• 10:00Steven Bartlett?

  What did you study?

• 10:01Dr. Stacy Sims?

  Exercise physiology and metabolism.

• 10:03Steven Bartlett?

  Okay.

• 10:04Dr. Stacy Sims?

  And then got into ultra running when I was doing my masters at Springfield. And then I started getting into more Ironman distance stuff before I started my PhD.

• 10:18Steven Bartlett?

  And you went to Springfield College as well?

• 10:20Dr. Stacy Sims?

  Yeah, so that was my masters.

• 10:22Steven Bartlett?

  Your masters?

• 10:22Dr. Stacy Sims?

  Yeah.

• 10:23Steven Bartlett?

  What did you study in your masters?

• 10:24Dr. Stacy Sims?

  That again was exercise phys and metabolism.

• 10:27Steven Bartlett?

  And then you did a PhD?

• 10:29Dr. Stacy Sims?

  Yep.

• 10:31Steven Bartlett?

  What was your PhD on as well?

• 10:33Dr. Stacy Sims?

  So my PhD was looking at differences between men and women in heat performance.

• 10:39Steven Bartlett?

  Okay.

• 10:39Dr. Stacy Sims?

  And how you climatize to it and how you hydrate for it, as well as looking between menstrual cycle phases and oral contraceptive pill use in women. And again, all of these topics were designed because of questions I had for myself or teammates had. And then from PhD, I went to Stanford and was working. In the high performance lab and then moved over to do a postdoc with Marcia Stefanic, who was the PI for the Women's Health Initiative, so looking at hormone replacement therapy in menopausal women, but also looking at exercise as a cohort to that.

• 11:21Dr. Stacy Sims?

  And I had another hand in the high performance research in human biology. So I would mesh human performance with public health.

• 11:30Steven Bartlett?

  Mm hmm.

• 11:31Dr. Stacy Sims?

  And then that transcended into a lot of the stuff that I do now, looking at what can we do, taking some of the ideas from high performance and apply it to the general population? And how does that improve people's longevity, wellbeing, but also for those who are trying to be parents, who have a high performing job, who want to do well in their age group race, whatever it is? How can we maximize some of the things we know from high performance with regards to sleep, heat, cold? And apply that to a person who's just trying to get everything done?

• 12:05Steven Bartlett?

  Hmm.

• 12:06Dr. Stacy Sims?

  And what small things they can tweak to improve their own training and performance?

• 12:10Steven Bartlett?

  And you've authored more than a hundred peer reviewed studies on exercise physiology?

• 12:15Dr. Stacy Sims?

  Yeah.

• 12:16Steven Bartlett?

  And you're a research scientist at the University of New Zealand?

• 12:19Dr. Stacy Sims?

  I am a research scientist at AUT. It's where most of my PhD students are, and we have a women's health program. And then I also have an adjunct with the Lifestyle Medicine at Stanford. So that's where a lot of the public health research comes in.

• 12:36Steven Bartlett?

  And when we talk about the differences between men and women?

• 12:40Dr. Stacy Sims?

  Mm hmm.

• 12:41Steven Bartlett?

  What exactly are those differences? Is it just the menstrual cycle that causes these differences? Or is there other physiological differences that we need to understand in order to understand the subjects we're going to talk about today around exercise, nutrition, and the variances between men and women there?

• 12:53Dr. Stacy Sims?

  There are sex differences in utero. I mean, when we look at...

• 12:57Steven Bartlett?

  What does that mean?

• 12:59Dr. Stacy Sims?

  So the sex difference is when the baby's developing.

• 13:01Steven Bartlett?

  Okay.

• 13:02Dr. Stacy Sims?

  So we look at stress, and the mom, under stress, we see that there's a higher incidence of a miscarriage if it's a developing boy fetus than a girl fetus, and it has to do with XX versus XY. Then after birth, we see that there's relatively little sex difference that is apparent until the onset of puberty. But when we're looking at those sex differences that aren't that apparent, they are there. We see that there's a sex difference in what we call muscle morphology. So that means that men are born with more fast twitch fibers. So they have more anaerobic capacity as they get older. They have more ability to produce power. We see that girls are born with more endurance type fibers.

• 13:45Dr. Stacy Sims?

  So this means they have more mitochondria for oxygen consumption and oxidative stress and being able to go long and slow. Then when we get to the onset of puberty, we see an expansion of these sex differences with the exposure of the sex hormones. So what we're seeing is now the boys are getting leaner, they're getting faster, they're getting more aggressive. But girls' bodies completely change because center of gravity drops from the chest down to the lower abdomen area because their hips widen. And their hips widen because, you know, being XX, they have to then accommodate for getting pregnant and eventually having a baby from a biological standpoint. Hips widen, shoulders widen.

• 14:30Dr. Stacy Sims?

  This changes the angle of the kneaded hip. So we then have a, yep.

• 14:35Steven Bartlett?

  So for anyone listening, this is, there's an image I have here, which I'll put on the screen and I'll also link below, and it's called the Q angle.

• 14:41Dr. Stacy Sims?

  The Q angle, yes.

• 14:42Steven Bartlett?

  Which is like the angle of my meter hip.

• 14:46Dr. Stacy Sims?

  Yep.

• 14:47Steven Bartlett?

  And it's showing that women's Q angle, basically like the shape of the gap between your leg, is, is it roughly 15 degrees? What is it? Do you know?

• 14:57Dr. Stacy Sims?

  Yeah, yeah. And so when we're looking at girls whose bodies are changing, we see that by the age of 14, girls who previously were sporty, over 60% of them drop out of sport. Because they're not taught that their bodies are changing, so they don't feel comfortable running or swimming or jumping or landing. Because they have a new cue angle, they become quad dominant. Their center of gravity is different, their shoulders are wider, so they don't feel comfortable running because their whole running mechanics change. So, you know, when we're looking at girls who are eight, they can keep up with the boys, right? Their bodies haven't quite started changing yet. By the time they're 10, they're starting to see a discrepancy. And I say that because my daughter's now 12, and I've seen it over the course of the elementary

• 15:41Dr. Stacy Sims?

  school years, where they used to be on par with the boys, playing soccer and rugby and stuff on the field. And then you start seeing a morph where the boys are becoming more aggressive and they're kicking the balls faster and running faster, and the girls are starting to develop a little bit more, getting a little bit more body fat, feeling a little bit more comfortable running. They can't do the monkey bars anymore because their center of gravity is lower, so they can't get up and do the monkey bars as well. But no one explains this to them. So then we see this discrepancy of being sporty, not sporty. We see, you know, these changes in body composition. And all of this is in those early stages of the teen years, which is another knock,

• 16:24Dr. Stacy Sims?

  because we also have brain changes, where girls become more self-aware and boys don't. They're like, okay, you know what? You pissed me off, I'm going to beat you up and we're going to get on with it. But girls are very self-aware and they hold things to themselves in a more negative fashion. And this creates a lot of mood changes. And this also creates a feeling of negative body positivity, so they don't feel that comfortable with how they look or who they are. And society doesn't help that either. So this all perpetuates in a sociocultural as well as a biological change with regards to exercise.

• 17:05Steven Bartlett?

  And as it relates to, we'll talk about the Q angle a little bit more in a second when we talk about exercise, but as it relates to the other changes, fat differences in men and women.

• 17:14Dr. Stacy Sims?

  Yeah. So if we see essential fat for men is around four to eight percent. So that means what we need for our nerves and just survival.

• 17:23Steven Bartlett?

  Yeah.

• 17:24Dr. Stacy Sims?

  For women, essential fat is around 12%.

• 17:27Steven Bartlett?

  Okay.

• 17:27Dr. Stacy Sims?

  So this is for nerves and, and looking around our central organs to survive. We look at body composition itself, we see that women tend to sit around 20% as a normal, healthy individual, although the data's changed over the years, and men sit around 15%.

• 17:48Steven Bartlett?

  And what about the heart? How's the heart different in men and women?

• 17:51Dr. Stacy Sims?

  So women have smaller heart and lungs.

• 17:53Steven Bartlett?

  Yeah.

• 17:54Dr. Stacy Sims?

  Relative to, relative body size to men. They also have less hemoglobin. So that means our oxygen carrying capacity is lower, uh, cause if we are looking at our red cells and we have four different, what we call heme molecules in a red cell and each one carries oxygen, our red cell count is lower as compared to men because the red cell count is driven by testosterone. So men have around a hundred percent more aromatized testosterone as compared to women. So this increases the carrying capacity of oxygen, which means it goes to the muscles, can deliver more fuel to the muscles to be able to contract better, have more power, more strength.

• 18:39Steven Bartlett?

  Does that mean women breathe more when they're exercising the same?

• 18:44Dr. Stacy Sims?

  Not that they breathe more. When we're talking about oxygen carrying capacity, this is the amount that you're taking into the lungs, how it transfers to the red cells to then be able to go to the working muscles to give the muscles the available fuel to do a contraction. So it's not a respiratory rate, it's the ability for you to breathe in and how fast that can be conducted to the muscle.

• 19:09Steven Bartlett?

  So there's going to be an impact on endurance then?

• 19:12Dr. Stacy Sims?

  It's more of a power and speed factor.

• 19:15Steven Bartlett?

  Okay, okay, okay. Cause the speed in which the oxygen can get to the muscles is what's being impacted and the volume of oxygen that can get to the muscles.

• 19:22Dr. Stacy Sims?

  Yep.

• 19:22Steven Bartlett?

  Okay, fine. And then you said the lungs are sort of, I read 25 to 30% smaller. Than a man's lungs typically.

• 19:31Dr. Stacy Sims?

  Yeah.

• 19:32Steven Bartlett?

  And what's the impact of that as it relates to exercise?

• 19:35Dr. Stacy Sims?

  So when we're looking at, I guess, world records, right, that have been kept, and we see there's a gender gap there. And this is slowly closing in the endurance world, but that has to do with muscle morphology with regards to being able to go long and slow. We're looking at the sprint capacity where we have to have a quick transference of oxygen and a quick muscle contraction. That gap isn't closing and that is because we have smaller, long, smaller heart. We have less blood volume, we have less red cells. So the overall capacity for quickly developing power and speed is at a smaller. I guess it's a limited capacity in women versus men.

• 20:20Steven Bartlett?

  And in your book, Raw, and page four, in the opening of the book, you talk about how women are 52% as strong as men in their upper bodies and 66% as strong as they are in their lower bodies. But when women train, they can become 70 to 80% as strong as men.

• 20:36Dr. Stacy Sims?

  So when we're looking at resistance training itself, we see that women relative to men can accommodate and develop muscle just as well as men in the lower body, but upper body not so much.

• 20:48Steven Bartlett?

  Okay, and we talked about this Q angle thing. One of the things that I'm really fascinated by is there's been a big conversation recently around ACL injuries in sport.

• 20:58Dr. Stacy Sims?

  Yeah.

• 20:59Steven Bartlett?

  And from reading your work, it seems that, and just doing some research online, it seems that this increase in women getting ACL injuries links somewhat to this Q angle situation, which again is the, I don't know how to explain it for someone that is listening on audio and can't see. But I will link it in this description, so I highly recommend you look at this picture because the minute you see it, it makes a ton of sense. But it's essentially like, and this is me probably butchering it. As a man, because my hips don't widen, my legs are effectively quite straight.

• 21:28Dr. Stacy Sims?

  Yep.

• 21:28Steven Bartlett?

  So from my hip down to my toes, it's quite straight, which means that. I'm going to be more sturdy. Say if I jump up in the air, when I land, this, I know this because my dad's an engineer. The center of gravity being straight means that I'm less likely to get injured. But if you're, is that right?

• 21:45Dr. Stacy Sims?

  Yeah, because your forces are going to be in a more linear fashion. So you have more even distribution of the force through the knee. But for women, as you're going to describe, our hips are wider. So we have more of an angle to the knee. And the forces aren't distributed evenly when we land. So when we look at that, as well as the quad dominance that develops for women, because, so that means that we use our front muscles of our legs, our quads, a lot more than our hamstrings, our posterior chain. So we don't use our glutes and our hamstrings by default as well as men do. So we're being pulled forward more and we let, we put more emphasis on the front of our body.

• 22:30Dr. Stacy Sims?

  Because those tend to take the, the quads tend to take the bulk of the muscle work that we're trying to do. Unless we're really trying to train hamstrings and glutes to fire, which isn't the default for women's bodies because center of gravity again is lower and you tend to lean forward. So when we're looking at ACL injury, again, it comes down to one, training stress, two, mechanics. And if we're not taught again, how to land, how to run, how to jump with the new angles, it predisposes people to severe ACL injury.

• 23:04Steven Bartlett?

  And how much more likely is a woman to have an ACL injury than a man?

• 23:08Dr. Stacy Sims?

  It is a higher rate, but the thing about the research is that there hasn't been a direct comparison. Because we hear incidentally that women tear their ACL. And so we see a lot of observational studies that women have torn their ACL. And we have lots of retrospective studies that are going back to, oh, where are we in our menstrual cycle when we tore ACL? But there hasn't been a definitive comparison between men and women. If we were to look at the current research, we see a three to four to one ratio of ACL tears of women versus men.

• 23:47Steven Bartlett?

  Three to four.

• 23:48Dr. Stacy Sims?

  So either three to one or four to one, depending on the research that you look. So three women for every one man, or four women for every one man.

• 23:59Steven Bartlett?

  Okay, so a 300% difference.

• 24:01Dr. Stacy Sims?

  Yeah.

• 24:01Steven Bartlett?

  Okay, so interesting. I know, absolutely never knew that. And in fact, it wasn't until I was looking through your work that I I'd seen, I went and did some research and there's a big conversation online, a lot in sort of news coverage around women's football, because it's, I think it's the fastest growing sport in the world.

• 24:18Dr. Stacy Sims?

  Yep.

• 24:18Steven Bartlett?

  But I read that the probability that a woman tears her ACL muscle is significantly like hundreds of percent more likely than a man because of this, in part because of this Q angle.

• 24:29Dr. Stacy Sims?

  In professional sport is not as much as when we're looking at recreational sport. Because when we're getting into professional sport, we have specific warmups, especially for football,

• 24:39Dr. Stacy Sims?

  put out by FIFA to prevent ACL tear, to make sure that you are actually properly warmed up and engaging the right muscles and learning how to stop pivot, because it's a, it's a mechanism in action usually is a twisting angle. But if we're looking at more age group or grassroots sports, because people aren't aware of this Q angle, they aren't aware of the quad dominance, women haven't been taught again how to work with these new mechanics. Then we're seeing a greater incidence of ACL tear.

• 25:09Steven Bartlett?

  Thirty female football players missed Women's World Cup in 2023 due to ACL injuries, including in the UK, Lioness Beth Mead and Leah Williamson. Which is staggering to me.

• 25:21Dr. Stacy Sims?

  Yeah, it's very high incidence, yeah.

• 25:24Steven Bartlett?

  So is there something that can be done if you're a woman that's exercising, that's doing things like jumping and running and sprinting and the fast sort of twitch sports? Is there something you can do to avoid having an ACL injury?

• 25:38Dr. Stacy Sims?

  It's all about being strong. So if we're looking at how, what is the biggest thing for ACL prevention? And I'll bring in one of my PhD students who's graduated, looked at ACL rehab after surgery. And it comes down to the definitive difference between quad and hamstring strength. So if we're looking at improving the strength capacity of the hamstrings, then it offsets some of the Default strength that the quads are taking. So if we're able to balance it from being front loaded to being more even loaded, it comes down to, you know how we were talking about distribution of forces through the knee with men being more linear and women having an angle.

• 26:20Dr. Stacy Sims?

  Well, if we're able to take that angle and we can evenly distribute the load between the muscles of hamstring and the quads of the front and the back.

• 26:27Steven Bartlett?

  Yeah.

• 26:27Dr. Stacy Sims?

  Then it pulls the forces more centrally.

• 26:30Steven Bartlett?

  Okay.

• 26:30Dr. Stacy Sims?

  Which reduces the stress of one point of contact.

• 26:34Steven Bartlett?

  Got you.

• 26:35Dr. Stacy Sims?

  So if we're developing the strength through the whole posterior chain, we're looking at glutes, we're looking at hamstrings, we're doing a lot of calf work. And we can develop that whole posterior part. It reduces the incidence of being pulled in one direction and the misalignment of forces. The other is the cutting motion, where we're looking at lateral movement. So a lot of times when we're looking at warmups and you're observing on like kids' sports, there's not a lot of lateral development. So if we're looking at prevention of ACL tear, we have to work a lot of the explosive lateral movements as well as jumping and single leg jumping. And these are things that aren't really done in grassroots. But as we start to get more into professional sport,

• 27:19Dr. Stacy Sims?

  it's becoming more and more apparent that we have to do specific mechanism of injury prevention. So they're looking at the sport. We're a football player, we have a high incidence of ACL potential. So we have to really develop our posterior chain. We have to work on our power for our lateral movements, our step and our jump. So this is part of what FIFA's put in for the warmup because there is such a draw. And as you're saying, that 33 women in the World Cup tore their ACL. Part of it is loading, part of it is a little bit maybe overtrained before they go into the World Cup. But a lot of it has to do with this imbalance between the muscles and now having to address it.

• 28:01Steven Bartlett?

  Did science just look at women as?

• 28:05Steven Bartlett?

  A different version of men, like, sorry, did they just look at women as like a

• 28:09Dr. Stacy Sims?

  Smaller version of men?

• 28:11Steven Bartlett?

  Is that what, how were they looked?

• 28:12Dr. Stacy Sims?

  Yeah, for the most part, because I mean, a lot of the stuff when I was going through school and even now textbooks. So I was standing in the metro in DC a few months ago and there was a young girl who has just gotten into exercise physiology and I overheard a conversation and she was talking about some of the experiments that they were doing, but it never, she never talked about, like, we have to make, you know, we're doing women specific, we're doing men specific. And I asked her, I was like, has anyone, you know, talked to you about how women's bodies are different than men's from angles and muscle morphology? And she's like, no, what are you talking about? I was like, this is the second year in ex-fiz now. And if you look at the textbooks,

• 28:53Dr. Stacy Sims?

  it's still a representation of men in the textbook with regards to images. You have him or they, you never have her. They might have a very small section in there about the female athlete, but usually it's about the female athlete and anemia or relative energy deficiency in sport. It's never about how we can empower women to use their bodies and their physiology to their advantage. And it's what, almost 2025 now?

• 29:23Steven Bartlett?

  Is there any element of it of people being too scared to talk about differences in physiology amongst men and women?

• 29:30Dr. Stacy Sims?

  I don't think so. I mean, I always explain it from historical perspective when we're looking at the history and when we started seeing the modernization of medicine. Prior to the modernization of medicine, it used to be women who were the caretakers. If you're thinking about, you get sick, you go and someone has an herbal remedy for you. But when we started medicalizing and becoming more nuanced in the medical education, women were excluded. So when we start looking at, at the origins of medicine and who was in the room, it was men. We start looking at the origins of science and science development, it was men. So all the scientific experiments and everything have always been a default to men. We look at AI now and they're learning from algorithms based on male data. So even

• 30:15Dr. Stacy Sims?

  now, healthcare is still heavily male oriented. So when we start looking at why women haven't been included or why women have been generalized to male data, it's just been the nature of how things have developed. Now that we're aware of it, and now we have more research money coming into women's health, we're starting to see a change. And part of the two definitive moments in healthcare research that really invoked this change, one was when we started seeing a lot of incidences with Ambien and the dosage of medicines where women were getting into a lot of accidents, car accidents, after they had taken Ambien because it was still in their system the next morning.

• 30:53Steven Bartlett?

  It's Ambien?

• 30:54Dr. Stacy Sims?

  It's a sleep aid.

• 30:55Steven Bartlett?

  Okay.

• 30:56Dr. Stacy Sims?

  It's a prescription strength sleep aid. So then people are like, whoa, what's going on here? Oh, the dosage for a 180 pound man is the same as 120 pound woman. And we also know that there's differences in body composition and metabolism. So a 180 pound man can take this dose and be fine in the morning, but 120 pound woman can't take that same dose and be fine in the morning. And then we have COVID and the outcomes of long COVID and the differences between the sexes with regards to women ended up with more long COVID, men ended up dying. So then during the COVID time period, people were like, whoa, there's sex differences in the outcomes of this disease. We have to really start looking at that. So

• 31:38Dr. Stacy Sims?

  there's slow things that are really impactful on society that now people are starting to step and say, wait, we have to really look at women as women. We have to look at men as men.

• 31:50Steven Bartlett?

  And is there an element of hormones impacting injury at all?

• 31:53Dr. Stacy Sims?

  There's always an impact of hormones. When we're looking at the overlay of hormones and sex hormones, and then the protocols that have been developed, they don't take into account estrogen, progesterone, and to some extent, testosterone. So if we're looking at injury and the way that estrogen makes more laxative ligaments, that means that our ligaments become more lax when estrogen comes up, which is why people assume that around ovulation is when people will have more ACL tears. It's not, because we also see that progesterone comes in and can have a different effect on the tendons. But

• 32:34Dr. Stacy Sims?

  that isn't accounted for in a lot of the protocols that are out there for training and prevention of overtraining. We see that when we're looking at male and testosterone, there tends to be, the more testosterone, the better for developing muscle and recovery, but that's not necessarily true either. So there's nuances in the sociocultural idea around sex hormones that also impact on our actual guidelines and protocols.

• 33:01Steven Bartlett?

  If a man and a woman came to you and said, I want to lose weight. They said, I'm 200 pounds and I'd like to lose some weight. Would you give them different advice on what to do?

• 33:11Dr. Stacy Sims?

  Absolutely, absolutely would. And it comes down to a lot of, we see this on social media all the time, calories in, calories out, right? So when we're looking at calories in, calories out, that idea of that algorithm can work well in men. And the reason for that is the hypothalamus. So we're looking at the hypothalamus, which is an area in the brain that controls appetite. It also controls our endocrine system. So for men, they don't have as many of what we call our kiss peptin neurons activated. So this is neurons that are responsible for when we have nutrients coming in. They fire, they're like, yeah, okay, we got enough nutrition coming in that we can now

• 33:56Dr. Stacy Sims?

  accommodate for developing muscle and losing body fat. For women, we have more areas that are very sensitive.

• 34:03Steven Bartlett?

  Sensitive to?

• 34:04Dr. Stacy Sims?

  To nutrient density. So when I say this, when we're talking about four grams of carbohydrate that come in, and say they're carbohydrate from fruit and veg, not from ultra-processed stuff. Those four grams of carb will affect the bodies differently between being a man and a woman. For a man, those four grams of carb coming in primarily will go blood sugar and then be stored as liver muscle glycogen. For women, it's blood sugar. It doesn't get stored. Because for women, in order to store muscle and liver glycogen, you have to have an activation of some enzymes from the liver, as well as some enzymes within the skeletal muscle itself to say, yeah, okay, we want to store this.

• 34:49Dr. Stacy Sims?

  We don't want to circulate it. So then we start looking at how the brain is perceiving that. So if the brain is saying, yeah, we can store this because there's still enough muscle tissue around, there's still enough blood glucose that we can keep going and we can survive the day. But for women, it sits there, the blood glucose sits there. And when it starts being used, the hypothalamus is like, okay, where's the extra food that's coming in so we can keep going and countering the stress that's coming in? And the best way from a numbers perspective to look at it is when we are looking at calorie, baseline calorie intake, just to exist and not get into any kind of endocrine or hormone dysfunction and appetite dysfunction. For men, it's fifteen calories per kilogram of fat free mass.

• 35:34Dr. Stacy Sims?

  For women, it's thirty. So we start to see men do really well on things like fasted training. We see men do really well on calorie restriction because the hypothalamus is not as sensitive to lower calorie intake, or to low carb intake, or to high protein and high fat intake. But for women, because the hypothalamus has more areas that are sensitive to nutrient density.

• 36:04Steven Bartlett?

  What does that mean? Sorry, I'm not even sure what the hypothalamus is.

• 36:06Dr. Stacy Sims?

  So the hypothalamus is an area in the brain.

• 36:09Steven Bartlett?

  Yeah.

• 36:10Dr. Stacy Sims?

  And it's sensing. So you have blood that circulates through the brain. It senses temperature, how hot your your blood is.

• 36:17Steven Bartlett?

  Like the thermostat or something of the body?

• 36:19Dr. Stacy Sims?

  Yeah.

• 36:19Steven Bartlett?

  Okay.

• 36:19Dr. Stacy Sims?

  So it's, yeah, it is a thermostat. It's the appetite control center. It's how your body responds to salt, how your body responds to protein, carbohydrate. Do I need more? Do I need less? So it's, it's like the control center for the most part. So for women who come in and they're doing fasted training, the hypothalamus is like, wait a second, we don't have any blood sugar. We don't have enough carbohydrate to actually do this kind of training. So what I'm gonna do is I'm gonna create a little bit of dysfunction here and I'm gonna start down turning all the other systems that need the same kind of fuel because I don't have enough just to do these muscle contractions.

• 36:59Steven Bartlett?

  So that means you could end up losing muscle?

• 37:02Dr. Stacy Sims?

  Absolutely. So if a woman comes to me, it's like, I want to lose weight. And I've been doing fasted training. I get up, I have a black coffee, I go to the gym, I do my lifting, I do some of my cardio.

• 37:13Steven Bartlett?

  My girlfriend does exactly that.

• 37:14Dr. Stacy Sims?

  And then I'm not that hungry because I did a hard workout at the gym. I might have a protein recovery shake and then I'll hold off eating my first meal until noon. I always turn to them and go, well, why did you go to the gym? Because all you've effectively done is burn through your lean mass. So your body needs to have some fuel. And the first thing that goes is lean mass because it's a very active component of the body. So it would be better for you as a woman to have maybe fifteen grams of protein. If you're going to do strength or fifteen grams of protein with thirty grams of carb, which isn't a lot, before you go do cardio and strength. Because this is just enough to raise your blood sugar

• 37:58Dr. Stacy Sims?

  to circulate to the hypothalamus that yes, there's some nutrition coming in. I'm able to get that blood sugar working. I'm able to get that blood sugar into the muscle. I'm able to stimulate the mitochondria in the muscle to actually use some more free fatty acids. I'm able to tell the liver that I can actually get through this and use these free fatty acids instead of storing them. It only takes a little bit of food to then have benefit for what you're doing. For a man, if he's like, comes in, I have a black coffee. I go to the gym, I do my strength, I might do a little cardio, have my protein afterwards, and then I might delay my meal. Like, that's all right, because you have a longer window for recovery. The hypothalamus isn't as sensitive. You're not burning through a lean mass.

• 38:42Dr. Stacy Sims?

  You're developing a stress on the body. And we know that it's really good that you have that protein post-exercise because that's going to create some muscle protein synthesis and hold you over till you have your meal.

• 38:54Steven Bartlett?

  Okay, so I'm going to try and explain this to you like I'm a ten-year-old, which is the exact level of IQ I have on this subject matter.

• 39:02Dr. Stacy Sims?

  Yeah.

• 39:02Steven Bartlett?

  So you've got this hypothalamus in the brain, which is basically this sensor. It's trying to figure out, make sure everything is in. I'm trying to think of that big word that someone taught me.

• 39:13Dr. Stacy Sims?

  Homeostasis?

• 39:14Steven Bartlett?

  Homeostasis. Everything is level, right?

• 39:17Dr. Stacy Sims?

  Yeah.

• 39:17Steven Bartlett?

  And a woman's hypothalamus is more sensitive. So if my partner wakes up, goes to the gym, has her black coffee, goes to the gym, does a big workout, as she always does, her body, her hypothalamus is going to.

• 39:33Steven Bartlett?

  Panic a little bit more because it's going to assume that there's stress on the body now. And it's going to look around to see if it has sufficient blood glucose levels. And it's, and it's not gonna, because she's not had anything for a while, she's not gonna have the sufficient blood glucose levels. So it's gonna start burning her lean muscle mass.

• 39:54Dr. Stacy Sims?

  Exactly.

• 39:54Steven Bartlett?

  Which means that she's, she's essentially gonna, it's like one step forward, one step back. Right, super simplified. For a guy, has his black coffee in the morning, goes to the gym, does the workout, the body looks. And because the hypothalamus is less sensitive, it's less requiring of there to be higher blood sugar levels, doesn't care as much. So it's going to.

• 40:19Dr. Stacy Sims?

  It can also tap more into our liver and muscle glycogen stores.

• 40:23Steven Bartlett?

  Okay.

• 40:23Dr. Stacy Sims?

  So it's gonna say, yeah, okay, well, we have a little bit of blood glucose, we need a little bit more, so let's tap into the stores and pull them out.

• 40:31Steven Bartlett?

  So it's less reluctant to go straight for my lean muscle mass.

• 40:34Dr. Stacy Sims?

  Exactly.

• 40:35Steven Bartlett?

  Okay.

• 40:35Dr. Stacy Sims?

  So it has an alternative fuel source.

• 40:38Steven Bartlett?

  Hmm, that's interesting. And what's the evolutionary story of this? Why, why does this make sense?

• 40:44Dr. Stacy Sims?

  When we look tribally, like there, and I might get hit by some sociologists who are like, wait, this isn't completely true, but for the exception, there are some tribes that didn't fit into this, but for the general idea from a biological evolutionary standpoint. When we had times of low calorie intake, so we had to go find the beast or we had to go out and find calories. It was at a disadvantage for the woman to be pregnant or to have a baby, an extra amount to feed. So in times of low food intake, the reproductive system or the endocrine system of a woman would wind down. So she would become amenorrheic or lose her menstrual cycle for a while.

• 41:24Dr. Stacy Sims?

  But it didn't affect men in that same way because they had to lean up and get fitter and faster because they had to go fight the beast or they had to go find the calories and bring it back. So when we're looking from that evolutionary standpoint, in times of low calorie intake or low food intake, a woman's body will start to conserve and wind down because it thinks there's a famine coming. But for men, they're not as sensitive and the body's like, oh, not a lot of calories coming in. That must mean there's a fight that I have to prepare for. So I'm going to lean up. I'm going to address all of my fuel systems so that I can tap into all these alternative fuel systems so that I

• 42:05Dr. Stacy Sims?

  will have the energy to be able to go and fight the beast to bring the calories back. So when there's adequate calories available, we see that women will lean up. They'll become more acutely aware, cognitive function comes up, carbohydrates are really important. So we see that there is a development of egg maturation. We have better endocrine pulse. So that means that our hormones that pulse on a daily basis, they actually have their full pulse and return to baseline to encourage the body to have a really robust endocrine system. So that's thyroid, that's our menstrual cycle, it's all the things. But when we start pulling the calories back, all that stuff winds down.

• 42:46Steven Bartlett?

  So what does that say about fasting?

• 42:49Dr. Stacy Sims?

  So this is the big debate, right? So we look at fasting and where it first came out and it's like, okay, we see that obese sedentary individuals who had to lose weight rapidly for surgery, they're put on a fasting type program to lose weight quickly in order to survive surgery. And unfortunately, a lot of those times, we look at clinical research and it gets transposed over to health and fitness without actually asking if it's viable. So then we look at the lower end of the fitness population, people who are just learning to move and wanting to move. And like, I also want to lose more body fat so that I can move better. Oh, I'll start fasting.

• 43:31Dr. Stacy Sims?

  And when we see a lot of the like push on it, it comes from male data again. So when we start looking at women and a lot of women used to come with their partners to see me and say, I don't understand, we're both doing the same kind of fasted training. He's leaning up and getting fitter. I'm putting weight on and getting slower. I'm like, okay, well, we have to separate it out, right? If you're a woman, you want to fast for all the health reasons that we hear about with regards to telomere length, improving longevity, improving our body's metabolic control. Then we work with our circadian rhythm where we stop eating at dinner. So we have dinner and we don't eat two to three hours before bed.

• 44:13Dr. Stacy Sims?

  We have the overnight fast and then you want to have food within a half an hour of waking up to blunt that cortisol peak that's natural upon waking. For men, you can have variations of fasting. You can do intermittent fasting, you can do warrior fasting and you can still have benefit. But for women, when we look at the data and if we were to do a warrior fast, which is a 20 hour fast, four hour eating window. For men, we see more parasympathetic drive, so they get that more focus. They have better blood glucose control. They get an acceleration of body fat loss. They become more metabolically flexible, meaning their body is able to transfer between carbohydrate and fat utilization.

• 44:57Dr. Stacy Sims?

  For women, it doesn't happen that way. For women who do a warrior fast, so that's a 20 hour fasting and four hour eating window. They end up with less blood sugar control. We have higher resting blood glucose. We have more fat storage. We have more sympathetic drives. That means the body's under stress and you're not going to be able to sleep or recover well. And we see a downturn of the thyroid within four days of doing this. So when we're looking at the data of fasting, again, it's pulling from the men and generalizing to the women. But when we start really looking and narrowing it down and looking at female specific data, the type of fasting that's out there in the health and fitness world is not appropriate for women.

• 45:42Steven Bartlett?

  But you would say that the sort of overnight fast. Eating dinner at a earlier time.

• 45:50Dr. Stacy Sims?

  At six, seven.

• 45:52Steven Bartlett?

  Six o'clock and then eating breakfast when you wake up at say eight in the morning or nine or something.

• 45:57Dr. Stacy Sims?

  Six or seven.

• 45:58Steven Bartlett?

  What about the like three day fast you hear about to get into like autophagy or whatever it's.

• 46:03Dr. Stacy Sims?

  Exercise is a stronger stimulus for autophagy than fasting. So if we look at exercise in itself is a fasting state. What happens during exercise? You start exercising, your body is trying to provide fuel. So it's breaking down fat, it's breaking down glucose, it's breaking down amino acids. It's also creating in a recovery standpoint, a boost of growth hormone, a boost of testosterone in both men and women. That creates the cell cleanup, which is autophagy. Right? So if we're looking at the difference between fasting and exercise, exercise is a stronger stress. All the things that we hear about fasting and longevity, exercise does the same. It's a stronger stimulus for it. But the problem is we've become a lazy society and people think exercise is too hard.

• 46:49Dr. Stacy Sims?

  As an exercise physiologist, it breaks my heart to see people who are struggling to walk down the street. Because we are so used to being conditioned to a certain temperature in a room to having a car automatic opener or Uber come so we don't have to walk down the road. And I bring up that movie Wally from the early two thousands with the little robot who's like wandering around society and you see all these people on these floating beds watching a screen. And one of the guys gets kicked off by Wally accidentally, falls down, he can't get up. And he's looking around going, well, why can't I get up? What's going on? I'm like, that's today's society where people are are not able to actually

• 47:33Dr. Stacy Sims?

  pull their own body weight around for a significant amount of time because it feels too difficult. Whereas we look at all the stuff that comes out with nutrition and all the trends that come out with nutrition, from fasting to carnivorous diet to, you know, the old fashioned paleo, all of these things that people are trying to do, we turn to exercise and we change the modalities of exercise. Are we doing intense exercise? Are we doing a low intensity? Are we doing resistance training? Are we doing cardio? What are we doing? All of these things and exercise are significantly stronger stress on the body that create more adaptive changes than all these crazy diets. But people find exercise too hard or they don't have time.

• 48:14Steven Bartlett?

  So funny, in that example where a man and woman come to you, you wouldn't recommend the woman to fast in the same way that you'd recommend a man to fast. Is there any differences that you'd recommend in training if their goal was to lose weight?

• 48:27Dr. Stacy Sims?

  Yep, absolutely. So when we're looking at regardless of age for women, because we see that women don't age in a linear fashion like men. So we had definitive points. We have puberty, we have our reproductive years, we have pregnancy in there, we have perimenopause, we have postmenopause. Each one of those is a different hormone profile that can affect the way we train. For men, you know, you just kind of go, and we start to see a decline of testosterone when we get into our late 50s. So we're talking about women and training. If someone is coming in and they're in their mid 30s and they're like, I want to lose weight, okay, resistance training. If someone comes in and they're in their mid 40s, then

• 49:08Dr. Stacy Sims?

  perimenopause, resistance training, doesn't matter. Resistance training is key for mobilizing abdominal fat and for creating more lean mass and also increasing the amount of crosstalk between their skeletal muscle and our stored fat through little things called myokines, which are hormone signals that are released during exercise and released from the skeletal muscle. So if we say, okay, let's do resistance training to really recomp the body. We also want to increase our protein intake because we see if you're doing a resistance training with a higher protein intake, then we have complete recomp over the course of 12 weeks. And it's a very powerful motivating tool for women because for the most part,

• 49:51Dr. Stacy Sims?

  women have been excommunicated from the strength world until recently. It wasn't kosher for women to have a lot of muscles. We see, like I grew up in the nineties with the supermodels that were super skinny, right? And it wasn't kosher for women to be in the gym lifting weights. But we see this evolution change. And so we're starting to see more research come out in women and resistance training. And it's so imperative for body composition change to invoke that resistance training.

• 50:18Steven Bartlett?

  What about a Zempec?

• 50:19Dr. Stacy Sims?

  A Zempec, yeah. So I find it interesting because of all the impact it's having on society. And it is a very powerful tool. The problem with it is no one is being necessarily taught how to come off it. So if we look at a Zempec and how powerful the GPL1 is, we see it does invoke an appetite switch where it mutes the appetite. It dampens cravings. So we see it's rapid weight loss, but that rapid weight loss is lean mass. So that comes back to the Wally picture where you can't get up because you don't have lean mass.

• 51:01Dr. Stacy Sims?

  I fear for society who doesn't have the opportunity to learn how to come off it through proper strength training, exercise modalities and nutrition to support the weight loss that comes with a Zempec use.

• 51:13Steven Bartlett?

  Mm hmm.

• 51:14Dr. Stacy Sims?

  It's absolutely brilliant tool. It's absolutely a brilliant tool, but we're falling on the behavior change. If we were to really teach people how to create that behavior change while they're using the tool, then they can come off it and not be afraid of putting weight back on.

• 51:31Steven Bartlett?

  Okay, so would you recommend it for your, for people that come to see you or ask you for advice?

• 51:37Dr. Stacy Sims?

  No, because most of the people that come to see me have those 10 vanity pounds they want to lose. I call them vanity pounds because they're the ones that creep up and you can instigate little changes within the.

• 51:49Dr. Stacy Sims?

  Daily life to actually lose them and keep them off. For people who are struggling, who have severe obesity, they're pre-diabetic, they have other medical conditions. And exercise is definitely in the too hard basket because they get breathless just getting up out of their chair. We need to lose some weight first so that we can then implement some of the adaptive changes of exercise.

• 52:11Steven Bartlett?

  And do you think women should be eating immediately after they exercise? And men? Or is it, does it, is there a variance there at all?

• 52:19Dr. Stacy Sims?

  There is a variance because when we look at what we call metabolism coming back down to baseline. So that's your overall body coming back down to its resting state. For women, it happens within thirty to forty minutes after exercise. For men, it's two to eighteen hours, depending on the intensity. So in that, we see that if we want to maximize our body's resistance training and muscle building capacity, we need to give it some food. We need to give it some really good hit of protein. For women who are in their reproductive years, we see thirty-five grams of protein post-exercise within forty-five minutes. We'll tip the muscle into muscle protein synthesis. For men, it's twenty grams and it can be two, four, whatever hours later.

• 53:04Dr. Stacy Sims?

  When we're looking at returning our muscle glycogen back to normal, we don't need as much carbohydrate post-exercise as a woman, as men need more because they tap more into their stores. So the window of opportunity for women post-exercise is around that forty-five minute mark, but for men, it's open a lot wider.

• 53:23Steven Bartlett?

  What about the keto diet for women?

• 53:26Dr. Stacy Sims?

  I am kind of anti keto for both sexes. And I say this because when we look at the gut microbiome, that is so important. We see a decrease in diversity as we become more and more, I guess, city dwelling and we are having less and less of variety in our food chain. We have to take care of the gut microbiome. If we look at the ketogenic diet and the high fat intake that comes with it, it significantly decreases that gut microbiome diversity, which reduces the body's ability to synthesize vitamins, to produce serotonin, to have this conversation between the gut and the brain.

• 54:07Dr. Stacy Sims?

  And for women, we're already metabolically flexible by the nature of being born with more of those endurance fibers, that there's no reason to try to do a ketogenic diet.

• 54:17Steven Bartlett?

  Could I not take a prebiotic or something, or just eat more fruits and veggies and stuff?

• 54:22Dr. Stacy Sims?

  So if you're eating a lot of fruit and veggies.

• 54:24Steven Bartlett?

  Sorry, not fruit, veggies.

• 54:27Dr. Stacy Sims?

  No. If you're eating a lot of fibrous fruit and veg, then that's how we increase the diversity. Taking a probiotic pill, it just affects the upper intestines, but even that is a little bit suspect because there's only two to three companies that are making all the probiotics that are B to B. So that means business to business. And we don't really know the long-term outcome, and we can have the overgrowth of some probiotics that again can cause some dysbiosis.

• 54:53Steven Bartlett?

  Could I be on the keto diet and still protect my gut microbiome?

• 54:57Dr. Stacy Sims?

  I don't think so. Not from what I've seen.

• 55:00Steven Bartlett?

  Because I thought the gut microbiome was predominantly about like plants.

• 55:04Dr. Stacy Sims?

  It is, but you also need some protein that comes from a wide variety of different sources. And the amount of fat that is taken in through a true ketogenic diet is 70 to 80% of your total intake coming from fat. And then that will cause the overgrowth of the bacteria that relies primarily on fatty acids, which down-regulates all the good bacteria that relies on our fibrous fruit and veg. Because you're not going to be able to consume as much fiber as you need on a ketogenic diet to really invoke this diversity. For thinking about invoking diversity, you want 30 different plants across the week. And on

• 55:46Dr. Stacy Sims?

  a ketogenic diet, you're just not capable of being able to eat as much to create that diversity. And the reason why it's really important for women to have that diversity is because we have some gut bugs that are responsible for our sex hormone metabolism. So we think about estrogen, progesterone, people think, oh yeah, well, it's released from the ovaries and the adrenals and it goes and it hits our target tissues. But we have this thing called the second pass where our sex hormones will be taken up by the liver, bound by sex hormone binding globulin, shot into the intestines through bile, unconjugated or unpacked by these little gut bugs and then shot back out in the circulation to work. If we have a lower diversity of the gut microbiome, we don't have those bugs that will help with

• 56:30Dr. Stacy Sims?

  our sex hormone, I guess, reactivation and the ability for the sex hormones to work optimally.

• 56:38Steven Bartlett?

  What about things like saunas and cold plunges?

• 56:42Dr. Stacy Sims?

  Yeah.

• 56:42Steven Bartlett?

  Is there a difference, a variance there between men and women?

• 56:45Dr. Stacy Sims?

  Absolutely. So if we're looking at cold plunge and it's all the rage, right? So we're seeing, let's get into ice water, it's going to evoke this massive parasympathetic response, I'm going to have lots of cognition and focus, it's going to create a hormonal response that improves my blood glucose, it's going to invoke a lot of autophagy and all the things that we see with fasting as well. And it gives me this incredible sense of being in control. Male data. We look at women who were in ice baths, it's too cold to invoke those responses. And the reason for that is we have differences in our skin sensation between men and women

• 57:29Dr. Stacy Sims?

  in with regards to thermoregulation. So women have more subcutaneous fat, so more fat under the skin. And we tend to vasodistract and vasodilate first. So that means that blood vessels will constrict tightly and then we'll start to have some internal changes. Or if we're too hot, we'll vasodilate first and then we'll have internal changes to create sweating. So if we look at a cold plunge, there's too much constriction and it becomes too much of a threat to women. And their bodies don't have the same response to ice water. We see that 15 to 16 degrees C or around 55 degrees Fahrenheit is optimal temperature for women to experience the same effect that men have with ice.

• 58:14Dr. Stacy Sims?

  So there's a sex difference in the temperature to invoke the same response between cold water immersion responses. In the sauna, everyone responds. And we see that the adaptation for sauna is different again for men and women. Because for women, with the difference of the vasodilation and the heat before they start sweating, it takes a longer time for core temperature to come up. So women can spend more time in the heat before they start to get changes in their hormone responses and blood volume adaptations. For men, they can go in and I kind of laugh. My husband will come in with me in the sauna and I'll sit there for like 10 minutes and not sweating yet. And he's like pouring, he's like, I gotta get out.

• 58:59Dr. Stacy Sims?

  And it takes me like 20 or 30 minutes in order to get the same response. So when we look at the the actual research and data that looks at acclimatization and looks at sauna invoking changes, we see again that women need more time, both long, long, longer time for an acute bout and longer time across the weeks in order to get the same cardiovascular adaptations as men.

• 59:24Steven Bartlett?

  Interesting. I didn't realize that. A typical ice bath is what temperature? It's minus one or something, or is it?

• 59:30Dr. Stacy Sims?

  I think it's zero to four degrees C.

• 59:33Steven Bartlett?

  Oh, okay. Zero to four. Okay. So you're saying that a woman should be near a 15?

• 59:38Dr. Stacy Sims?

  Mm hmm.

• 59:39Steven Bartlett?

  For the same benefits?

• 59:41Dr. Stacy Sims?

  Mm hmm. Yep.

• 59:43Steven Bartlett?

  At my company Flight Studio, which is part of my bigger company Flight Group, we're constantly looking for ways to build deeper connections with our audiences. Whether that's a new show, a product or a project. It's why I launched the Conversation Cards. I've relied on Shopify before, who's a sponsor of today's podcast, and I'll be using them again for the next big launch, which we'll hear about soon. And I use them because of how easy it is to set up an online store that reaches all of you, no matter where you are in the world. With Shopify, the usual pain points of launching products online disappear completely. No matter the size of your business, Shopify has everything you need to make your business go to the next level and better connect with your customers all over the world. To say thank you to all of you for listening to my show, we're giving you a trial, which is just $1 a month.

• 1:00:27Steven Bartlett?

  You can sign up by going to Shopify.com/Bartlett. That's Shopify.com/Bartlett. Or find the link in the description below. One of the conversations I had with my partner last year at New Year's Eve was about creatine.

• 1:00:41Dr. Stacy Sims?

  Yeah.

• 1:00:42Steven Bartlett?

  I had had some with me on the counter in our in our home and we were away from home. And I said to her, I said, oh, you should take some. And her response was, no, that's not for women. And she went on to explain that she felt it was for effectively like bodybuilders.

• 1:00:58Dr. Stacy Sims?

  Yeah.

• 1:00:59Steven Bartlett?

  And that it would like put on weight. And I was like, I don't think that's true. I said, some people on my podcast have told me that everyone should be taking it.

• 1:01:05Dr. Stacy Sims?

  Yeah.

• 1:01:05Steven Bartlett?

  And so we sat there and Googled it. And after Googling it for a couple of minutes, she was like scooping it into her drinks whilst she possibly could. But there is a prevailing narrative here. Actually, before you came, I asked AI a couple of questions about women's perceptions on creatine. And the number one thing was women thought that it would gain muscle and gain weight. And they thought it was for bodybuilders.

• 1:01:31Dr. Stacy Sims?

  Yep, that is the prevailing myths around creatine. And what's the expression people use, the dose or the poisons in the dose? Right, so that's part of the creatine. So if we're looking at the bodybuilding set and how it increases muscle capacity and training status. So if we're using a lot of creatine, the dosing for bodybuilding is five grams, four times a day with one gram of carbohydrate. And we see that creatine helps store water within the muscle with glycogen. And we want that for muscle performance because the idea of being able to train harder with creatine is to enhance the amount of of enzymes that are available for muscle contraction.

• 1:02:14Dr. Stacy Sims?

  And creatine is part of the buffering system of that. If we're looking at creatine for health and for women, the dose is three to five grams only once a day without carbohydrate. And the reason for that is women have around seventy percent of the stores that men have, by the nature, for the most part, don't eat as much creatine filled food as men. And we see that we use it for a lot of our fast energetics. So like for our gut health, for our brain health. Um, and then also for muscle performance. So if we're having women take three to five grams once a day, it does not have the same side effects as the bodybuilding set of taking five grams four times a day.

• 1:02:56Steven Bartlett?

  Yeah, because on the label, it tells me to take it a few times a day.

• 1:02:59Dr. Stacy Sims?

  Yeah, you don't have to.

• 1:03:01Steven Bartlett?

  And it says about loading.

• 1:03:02Dr. Stacy Sims?

  So this is all the bodybuilding stuff, right? So if you want to load, we see a loading protocols over the course of two weeks. And you're starting to really saturate the body with those five grams four times a day. But for women, we see that three to five grams will fully saturate the body over the course of three weeks. So that means that all our fast energetics, like I said, our gut, um, the intestines, and we're looking at the integrity of the intestinal cells and the mucosal lining. And we see that there is a greater incidence of GI distress in women. I think it's something like a five to one ratio of women to men having GI distress running. And it has to do with estrogen, but also has to do with what we call the mucosal lining of the intestines.

• 1:03:45Dr. Stacy Sims?

  So we want to maintain the integrity of the mucosal lining and creatine is really important for that. So if we're looking at saturating the body over three weeks with three to five grams, we improve that integrity. So we have less GI distress. We also see that there have been randomized controlled trials looking at mood and with specifically with regards to depression and anxiety. And women who are taking three to five grams of creatine will come out of a depressive episode more so than women who are just using an SSRI. So it's really important for brain metabolism. And when we're looking at that whole loading strategy for men, that's all about muscle performance. It's not about gut health. It's not about brain health. It's about muscle performance.

• 1:04:30Steven Bartlett?

  Just looking at some studies, creatine supplication, creatine supplementation for both men and women enhances muscle strength, increases lean muscle mass, improves high intensity exercise performance.

• 1:04:40Dr. Stacy Sims?

  Yep.

• 1:04:40Steven Bartlett?

  And improves recovery, has potential cognitive benefits and supports in neurodegenerative diseases.

• 1:04:47Dr. Stacy Sims?

  Yes. So Abby Smith Ryan is a colleague out of UNC and she's done a lot of work in creatine for women. And yes, we see that there is an improvement in muscle capacity because you're increasing the amount of buffer that's available for muscle contractions, but it doesn't have to be the same loading dose as men. If you're looking for performance enhancement because you want to improve a training block or you're in physique building or you're going to do something like high rocks and you need to have greater muscle capacity, you might want to try the loading strategy. Yes, you will gain water weight because you're also storing more within the muscle. But for the general woman who's looking for health and performance benefits,

• 1:05:30Dr. Stacy Sims?

  you don't have to do a loading strategy. You just have to do that three to five grams a day.

• 1:05:34Steven Bartlett?

  That loading strategy for anyone that doesn't know is basically some of the creatine boxes will tell you, the labels will say for the first week or two weeks, whatever, have a huge dosage of it and then thereafter you can kind of ease down the dosage. But I think that's kind of been debunked to something that we all need to do in all cases.

• 1:05:51Dr. Stacy Sims?

  Yeah.

• 1:05:52Steven Bartlett?

  Are there any other supplements that you recommend women to take based on the way that we live our lives and the food that we eat?

• 1:05:58Dr. Stacy Sims?

  Vitamin D.

• 1:06:00Steven Bartlett?

  Okay. And why? And what does that do?

• 1:06:02Dr. Stacy Sims?

  So if we're looking at vitamin D, especially vitamin D3.

• 1:06:05Steven Bartlett?

  What's the difference?

• 1:06:07Dr. Stacy Sims?

  So you have vitamin D2 and vitamin D3. Vitamin D2 is more of a storage form. It's not converted to being a functional form. So if you take D3, it's already a functional form. So it means your body's going to take it in and use it as it should be. So we're looking at a vitamin D3 supplement, then we are able to boost circulating levels of vitamin D3 or vitamin D that's usable and it's used for every system in the body. And it's really important now, especially I'm coming from the southern hemisphere just out of winter. You're in the upper parts of the northern hemisphere in the middle of winter and we don't get enough sun. And when we're looking at now, all the worries for skin cancer, people are slip, slap, slop, you know, sunscreen, hat, clothes, and we don't get enough.

• 1:06:50Dr. Stacy Sims?

  And then if we're looking at our food supply, there's not a lot of proper vitamin D rich foods. You're looking at mushrooms or fortified dairy products. And those tend not to be consumed a lot nowadays. So if we're improving the amount of vitamin G3 that we're taking in and the amount of vitamin D that's circulating, we have better recovery, we have better muscle function, we have better brain health, we have, pretty much every system is affected in a positive way.

• 1:07:16Steven Bartlett?

  Omega 3?

• 1:07:17Dr. Stacy Sims?

  Yeah, omega 3s are good, especially as we get into peri and post menopause. We want to look at how inflammation affects the cells. So if we look at using a really good vitamin, or sorry, a really good omega 3, and omega, I guess we're looking at the types of omega 3s that are in there, then we're enhancing cellular integrity that our estrogen used to help with anti-inflammatory properties. It's not something that everyone needs to take. It's something that we have to consider when we start getting into our late 30s, early 40s, maybe get a blood test for it, see how your omega 3 levels are, and then consider dosing with a really good fish oil.

• 1:08:00Steven Bartlett?

  What about iron levels? Because I've had a friend of mine, who is a woman, tell me that their iron levels were low.

• 1:08:08Dr. Stacy Sims?

  This is common. And we see that there's the incidence of a change in the norms when we're looking at the reference ranges. And I find it really interesting that the reference ranges that we have for all of our blood markers are shifting to a sicker population.

• 1:08:31Steven Bartlett?

  What's that mean?

• 1:08:32Dr. Stacy Sims?

  So if we're looking at the bell curve, and we're taking population data, overall, our society has become sicker. So now we're seeing that the norms for iron used to be a ferritin of 50 or lower was considered low ferritin. Now it's 26 for women. We look at testosterone, lower testosterone now for men is normal. And it is because that is just what a sedentary population now presents. But if someone is active and comes to me and says, you know, I had my iron tested and it's sitting at 26, and they say that it's normal, but I feel awful. It's like, that is not normal. If you were a part of my high-performance athletic crew,

• 1:09:14Dr. Stacy Sims?

  we want to see minimum fifty, preferably a hundred. So we have to supplement you to bring it up. And it's a really specific area of how we supplement. It's supplementing every other day with a very high bioavailable iron. And when we start looking at how we are supplementing every other day with either a carbonal or a glycinate, then we're really able to boost that ferritin and people start to feel better.

• 1:09:41Steven Bartlett?

  What does iron do? And how does someone who's iron deficient feel?

• 1:09:46Dr. Stacy Sims?

  So iron is responsible for that, those heme groups that I was talking about with oxygen carrying capacity.

• 1:09:52Steven Bartlett?

  Hemoglobin, the blood, the blood cells.

• 1:09:54Dr. Stacy Sims?

  Yeah, their blood cells. So iron is responsible for allowing those heme groups to carry oxygen. If we have low iron, then we don't have enough oxygen circulating throughout the body or being used by the body. So you feel very flat, very tired. You start to get really dark circles under your eyes. It's a mission to do anything. So it's like a dead-end fatigue. And people are like, this, this isn't stress-oriented fatigue or jet lag-oriented fatigue. This is fatigue where I can't even walk up the stairs without getting winded.

• 1:10:28Steven Bartlett?

  What foods have iron in them or iron-rich?

• 1:10:31Dr. Stacy Sims?

  So primarily red meat is where a lot of people turn to. But if you are more plant-based, then we look at leafy greens. We look at nuts and seeds, but using a lot of vitamin C with that, preferably adding a little bit of olive oil on our salads, maybe cooking in an iron skillet to improve the amount of iron that comes into the food. And we also know that we have to time it with what we call hepcidin or hepcidin, depending on where you come from in the world. It's an enzyme that decreases the body's availability of iron absorption. It increases with inflammation. So it's higher after training for about five hours in men and

• 1:11:16Dr. Stacy Sims?

  in reproductive women. And it can be elevated for up to 24 hours in late peri and early postmenopausal women. So basically, how do I supplement? Supplement before training or at night away from training?

• 1:11:28Steven Bartlett?

  When you think about men's and women's diets, is there anything to be aware of when we're thinking about? Because, you know, me and my partner will sit down for dinner. And we share the food.

• 1:11:37Dr. Stacy Sims?

  Yeah.

• 1:11:38Steven Bartlett?

  So we, you know, food comes out, we, even when we go to a restaurant, sometimes we'll order the exact same thing and we'll both finish it.

• 1:11:44Dr. Stacy Sims?

  Yeah.

• 1:11:45Steven Bartlett?

  Is that okay?

• 1:11:47Dr. Stacy Sims?

  Is it, is it working for you guys?

• 1:11:49Steven Bartlett?

  I, I think part of the reason I ask is when I did some um blood glucose tests.

• 1:11:54Dr. Stacy Sims?

  Yeah.

• 1:11:54Steven Bartlett?

  I think, I, I think if I recall this correctly, my partner was more sense glucose sensitive than me. And I recall them telling me that women are, have a greater blood sugar sensitivity than men.

• 1:12:07Dr. Stacy Sims?

  So this is the interesting part. So when we're looking at blood glucose and insulin sensitivity, it changes across the menstrual cycle. So it depends on is she in the high hormone phase or not. If she's in the high hormone phase, which is after ovulation, uh we have more insulin resistance. And the reason for that is when progesterone comes up, it's trying to take in everything as a building block for the uterine lining.

• 1:12:34Steven Bartlett?

  Insulin resistance, what does that mean?

• 1:12:36Dr. Stacy Sims?

  So insulin is the hormone that, that is a signal for your muscles to uptake glucose, to store it.

• 1:12:46Steven Bartlett?

  Okay, so it sends a signal to grab the glucose out my blood, store it, which brings my glucose levels down?

• 1:12:51Dr. Stacy Sims?

  Exactly.

• 1:12:52Steven Bartlett?

  Okay.

• 1:12:53Dr. Stacy Sims?

  Exactly. When progesterone's in the picture, insulin doesn't do its job very well.

• 1:12:58Steven Bartlett?

  Okay.

• 1:12:58Dr. Stacy Sims?

  Cause progesterone wants to have more carbohydrate available to be able to then send it to the developing uterine lining, the endometriosis. Because the endometriosis becomes a really thick layer of tissue that is really rich in glycogen. So progesterone increases lean mass breakdown, or you increase your protein intake to have more circulating amino acids. It also makes your body less apt to store glucose because it wants both amino acids and glucose to build this lush uterine lining. When we get into perimenopause.

• 1:13:40Dr. Stacy Sims?

  We have more insulin resistance because there's confusion across all systems of the body. And the body is like, I don't know if I'm going to need this glucose or not, so I'm not going to store it. And there's a misstep in the liver and a misstep in the mitochondria, which is responsible for tapping into using free fatty acids with carbohydrate. So the body is having a higher level of like glucose because the body doesn't know if it should store it or not. So when your partner gets tested, it depends on how old she is and what phase of the menstrual cycle, or if she's well beyond that.

• 1:14:15Steven Bartlett?

  So the part of the menstrual cycle where her progesterone is highest is when she's going to be most sensitive to sugar?

• 1:14:24Dr. Stacy Sims?

  Exactly.

• 1:14:25Steven Bartlett?

  And that is typically between day nineteen and twenty-three if she has a normal cycle, a regular cycle or whatever.

• 1:14:31Dr. Stacy Sims?

  Well, the caveat there is ovulation. Is she ovulating or not?

• 1:14:36Steven Bartlett?

  Okay.

• 1:14:37Dr. Stacy Sims?

  And unfortunately, we're seeing in the modern fertility literature that women are having more and more anovulatory cycles. But you won't necessarily know that because you'll still have a bleed.

• 1:14:47Steven Bartlett?

  What's an anovulatory cycle?

• 1:14:49Dr. Stacy Sims?

  You don't ovulate.

• 1:14:50Steven Bartlett?

  Why?

• 1:14:51Dr. Stacy Sims?

  They're looking at a lot of the stress that's coming on today's society, the food system, a lot of the, I guess, trendy diets that are out there. A lot of women are eating enough to support their immune or their menstrual cycle function to allow the egg to actually develop to then instigate ovulation. And it's not just in active women, it's across the board.

• 1:15:16Steven Bartlett?

  So as it relates to this menstrual cycle, twenty-eight days, I'm going to put it on the screen for anyone that doesn't understand it or doesn't know what I'm referencing right now. I'll also link it below in the comments in the description, sorry.

• 1:15:30Steven Bartlett?

  Twenty-eight days long, there's the early follicular stage, the late follicular stage, the mid luteal.

• 1:15:37Dr. Stacy Sims?

  Luteal.

• 1:15:37Steven Bartlett?

  That's exactly what I said.

• 1:15:38Dr. Stacy Sims?

  Yep.

• 1:15:39Steven Bartlett?

  And the luteal phase.

• 1:15:40Dr. Stacy Sims?

  Yeah, yeah, yeah, yeah.

• 1:15:42Steven Bartlett?

  As it relates to nutrition and exercise.

• 1:15:44Dr. Stacy Sims?

  Yeah.

• 1:15:44Steven Bartlett?

  How do I need to adapt across these twenty eight days? And why do I need to adapt?

• 1:15:50Dr. Stacy Sims?

  So again, it comes down to the ovulation, right? So if we're looking at the low hormone phase, so that's your follicular phase.

• 1:15:58Steven Bartlett?

  Day one to six roughly.

• 1:16:00Dr. Stacy Sims?

  Yep, and even up to ovulation.

• 1:16:02Steven Bartlett?

  Which is where?

• 1:16:02Dr. Stacy Sims?

  So around day twelve or thirteen on a twenty eight day cycle. So right at that peak.

• 1:16:08Steven Bartlett?

  To thirteen, oh, yeah.

• 1:16:09Dr. Stacy Sims?

  Yeah, yeah, yeah, there. So this is where the immune system is really robust. And we're really resilient to stress. And we can have a lot of carbohydrate and protein intake. And we're not going to be that affected. We're more sensitive to glucose. It's going to be pulled into places it needs to be. If we ovulate, after ovulation, like I said, progesterone comes up. It's only produced if we ovulate because progesterone is produced from the breakdown of the housing of the egg. Progesterone, like I said earlier, will hold everything in the blood. It will, it will tell the body, we need more blood glucose and we need that glucose to come to the endometrial lining. We also need more amino acids.

• 1:16:53Dr. Stacy Sims?

  So we're going to break down lean mass or I'm going to make this person crave more protein oriented foods. So that I can have amino acids to come in. So if we're looking at adapting, right? The only real thing that we need to be aware of is after ovulation, if we're going to do a high intensity workout, we need to make sure that we have some more carbohydrates. So we're actually eating before and after having some good carbohydrate that comes in.

• 1:17:17Steven Bartlett?

  Which is from day fourteen onwards?

• 1:17:20Dr. Stacy Sims?

  Yep.

• 1:17:20Steven Bartlett?

  So from day fourteen onwards, if we are going to do a lot of a high intensity workout or high, a big workout.

• 1:17:27Dr. Stacy Sims?

  Yep.

• 1:17:28Steven Bartlett?

  Then we need to just make sure we're having more carbs.

• 1:17:30Dr. Stacy Sims?

  Yep. And then we have around a twelve percent increase in our protein needs because we have a higher amount of amino acids that are needed. One, because we're developing tissue, but two, we also have skeletal muscle turnover that we need to keep up with.

• 1:17:45Steven Bartlett?

  Interesting.

• 1:17:48Steven Bartlett?

  So is there any day in the cycle where we shouldn't be working out hard?

• 1:17:53Dr. Stacy Sims?

  That's individual. So it used to be early days when menstrual cycle research was coming out. We saw on a molecular level that the low hormone phase was where we could really push it and we could really get really good adaptations because our body was really responsive to stress. Then after ovulation, we see a fuel shift. Like I said, progesterone is really conserving or pulling glucose away. Estrogen's also sparing it and saying, you know, you need to go to the uterine lining. So with the change of hormones, we have a change in our fueling system. We also have a change in our core temperature where it goes up by about 0.5 or 0.5 degrees Celsius or around 1 degrees Fahrenheit. So our heat

• 1:18:36Dr. Stacy Sims?

  tolerance isn't as great. But because we're seeing more and more an-ovulatory cycles, we have to rely on the woman to track our own cycle.

• 1:18:44Steven Bartlett?

  Which is hard.

• 1:18:45Dr. Stacy Sims?

  Well, it doesn't have to be as hard as what people think. It's the nuance of how do I feel today? So I tell women, instead of really dialing it in and saying, oh, well, I think I ovulated today, so that means I should back it down. When you go to the gym, use what we call sessional rating of perceived exertion. So I tell people, most of the time you're going to go in, you can have a physical and a mental, right? Physical, how are you on a 1 to 10? Mental, how are you on a 1 to 10? If physically you're an 8 and mentally you're a 2, warm up really well and see if that mental capacity comes back up. If not, then we're not going to push too hard. We're not going to work on technique because mentally, you're just not there. Physically, maybe you are. If you go in and you're low on both of them, then it's going to be a technique and recovery

• 1:19:29Dr. Stacy Sims?

  day. You're not wasting time at the gym. You're going to make it work for you by really working slow under the bar, nailing technique, not getting the heart rate up so much. And as we're going through and tracking how we feel, we're going to start to see patterns across our cycle. And we can anticipate those patterns and say, okay, well, I know on day 21, I always feel flat. So I'm not going to schedule a high intensity workout that day. I'm going to sleep in, maybe do some mobility, recover, and really know that I'm not going to nail it that day. So I'm not going to go push myself because I don't want to beat myself up mentally. Because women do this. They're like, I suck. I don't know why. But it comes down to that physiological variability. And for a woman to track her

• 1:20:14Dr. Stacy Sims?

  own cycle, understand her own nuances. If you're really on to it, and you know when you ovulate, then you can take those molecular structures into play. Where you know you can hit your PR, and you can really push it in the low hormone phase. After ovulation, you're going to switch it to more endurance, maybe not so high intensity, but more tempo type work. And then about the four or five days before your period starts, where your immune system's more compromised, you just kind of want to dial it down uses as deload. So we can take the strength and conditioning ideas of building up macro-micro cycles and deload across the menstrual cycle.

• 1:20:51Steven Bartlett?

  So where in this cycle am I going to be strongest if I'm a woman?

• 1:20:54Dr. Stacy Sims?

  So if we're looking from a cognitive and a physicality aspect, it's right around where that estrogen starts to come up. So around day six.

• 1:21:05Steven Bartlett?

  Day six?

• 1:21:06Dr. Stacy Sims?

  To about day 13.

• 1:21:07Steven Bartlett?

  Day 13?

• 1:21:08Dr. Stacy Sims?

  Yeah.

• 1:21:08Steven Bartlett?

  Okay. And where am I going to be least strong theoretically?

• 1:21:12Dr. Stacy Sims?

  From about day 23?

• 1:21:15Steven Bartlett?

  Yeah, yeah.

• 1:21:17Dr. Stacy Sims?

  Yep. As those hormones start to come down?

• 1:21:19Steven Bartlett?

  Yeah.

• 1:21:20Dr. Stacy Sims?

  To 28.

• 1:21:22Steven Bartlett?

  Oh, okay. To the very end.

• 1:21:23Dr. Stacy Sims?

  Yeah, the very end. And the variation of those hormones coming down is what instigates a total inflammatory response. So if we're looking at inflammation, which drives the menstrual cycle to start the bleeding phase, we have a change in our immune system.

• 1:21:37Steven Bartlett?

  Bleeding happens at twenty eight.

• 1:21:39Dr. Stacy Sims?

  Around day twenty. So we say bleeding is day one in a cycle is day twenty eight.

• 1:21:44Steven Bartlett?

  Of course, yeah, day one to day six typically. Okay, fine.

• 1:21:47Dr. Stacy Sims?

  Yeah.

• 1:21:47Steven Bartlett?

  Well, I guess the question is, what questions should I be asking about the menstrual cycle?

• 1:21:52Dr. Stacy Sims?

  Well, you know, the questions that are never asked is like, what is a typical menstrual cycle? Yes, we have a textbook, like from one to twenty eight. That's very, very rare. Most women have a cycle that might be twenty one to forty days. The bleed cycle is something that's never talked about. What does a bleed cycle look like? Is it really six days? No, every woman has a different one. And if you're tracking what that bleed is, maybe you have two heavy days, a light day, and another couple of days of spotting, and then a heavy day, that's your norm. When you start having changes in the norm, that's when you want to look and say, am I getting into low energy availability? Am I not recovering well enough? Or am I in my late thirties, early forties, and I started getting into perimenopause?

• 1:22:34Dr. Stacy Sims?

  The bleed pattern is so important for people to understand because that's how we have a true inherent identification of stress. So we see changes in the bleed pattern as well as the length of the menstrual cycle itself, when the body's not adapting to stress. And stress isn't just our daily life stress, it's exercise stress.

• 1:22:58Steven Bartlett?

  And that disruption could also be just not having a bleed.

• 1:23:01Dr. Stacy Sims?

  Yes.

• 1:23:02Steven Bartlett?

  Because a lot of women talk about that. They talk about having irregular periods or just the period didn't come this month. Is that often an indicator of the body being under stress?

• 1:23:11Dr. Stacy Sims?

  Yes.

• 1:23:12Steven Bartlett?

  And that stress can be not just bad emails at work, but it could be you're working out too much or something.

• 1:23:17Dr. Stacy Sims?

  Yeah, working out too much, not eating enough is a big one. We've done some really interesting research, looking at recreational female athletes. So people who go to the gym three or four times a week, right? They're not training specifically for anything but life. And they tend to fall into some of these trendy diets, like fasted training, or maybe they're eating too low carbohydrate because they're on a low carb, high fat, or a high protein diet, and they're missing on the carbs. And again, that interrupts the hypothalamus. So we call it low energy availability. When someone isn't eating enough for the hypothalamus to say, yeah, all of our systems can work and we can adapt to exercise.

• 1:23:57Dr. Stacy Sims?

  So we see on the upwards of 55% of recreational female athletes in a low energy state or subclinical low energy state. And it comes out as changes in the bleed cycle or a missed period. That's why I tell women, look, if you're tracking, you can do sessional RP, but really track that bleed pattern and the length of the cycle. Because if you start to see changes in the length and changes in the bleed pattern or just changes in the bleed pattern, it's an opportunity for you to take a pause. Say, what, what have I done from a training perspective or a sleep perspective? Or somehow increased my stress that my body's not adapting well? Because if we do that first, then we don't get into a clinical position of amenorrhea,

• 1:24:41Dr. Stacy Sims?

  which is no menstrual cycle and poor bone health and psychological issues and things that all come with endocrine dysfunction.

• 1:24:49Steven Bartlett?

  Why is bone health so important for women in particular?

• 1:24:52Dr. Stacy Sims?

  When we see bone, it is driven by estrogen, progesterone, an interplay between estrogen and progesterone. We see a peak velocity or peak bone mass hitting around the time we're 20-ish. And then we'll start to degrade it if we're not creating multidirectional stress on the bone through jumping, through resistance training. And if we start to lose bone density and we become osteopenic or osteoporitic, meaning we have very thin bones, they break easily. And it's really, really difficult for someone who is in their reproductive years to, to be able to do all the things they want to do

• 1:25:37Dr. Stacy Sims?

  if they don't have a really strong, robust skeletal system.

• 1:25:40Steven Bartlett?

  And this is why vitamin D is also so important?

• 1:25:42Dr. Stacy Sims?

  Yes.

• 1:25:43Steven Bartlett?

  Okay. And men and women have different bone density?

• 1:25:47Dr. Stacy Sims?

  Yep. Men have thicker bones and tend to not have as much degradation of the bone because they don't have estrogen, progesterone perturbations that are changing the signaling to. Increasing bone density or stopping the growth of bone.

• 1:26:03Steven Bartlett?

  Right.

• 1:26:03Dr. Stacy Sims?

  So, women have this perturbation throughout their menstrual cycle that will change how their bones are responding. And then when we don't have a menstrual cycle, or we get put on an oral contraceptive pill, we have changes in that signaling which changes our bone density.

• 1:26:19Steven Bartlett?

  And you mentioned sleep a second ago.

• 1:26:20Dr. Stacy Sims?

  Yeah.

• 1:26:20Steven Bartlett?

  How is sleep relevant and what's the variance between men and women as it relates to sleep?

• 1:26:24Dr. Stacy Sims?

  Sleep's really important because that's where we have our parasympathetic drive and our ability to recover. So, the whole, I shouldn't say the whole reason, because nobody really knows why we need to sleep, other than the fact this is where our physical and our mental capacities become solidified. So, that means that our body fully repairs while we're sleeping, our memories get solidified, our brain becomes a little bit relaxed and can repair itself while we're sleeping. For women, we see changes across the menstrual cycle in our sleep phases. So, when we are, so sleep phases, meaning our deep sleep versus our late sleep versus our dream sleep. And we need to get in that really super deep

• 1:27:03Dr. Stacy Sims?

  sleep in order to have optimal reparation. When we are getting close to the bleed phase, then we see more interruption in the sleep. And it's really, really apparent for women who have really bad PMS, or other conditions that happen to affect estrogen and progesterone. We have an increase in our core temperature from progesterone, we have changes in melatonin pulse because of estrogen. So, when women are talking about having really poor sleep right before their menstrual cycle, it is because we have these sex hormones that are interfering with our sleep phases. For men, they don't have that perturbation. For men,

• 1:27:41Dr. Stacy Sims?

  we see that chronologically, they tend to have a melatonin peak that's later than women. So, they tend to want to stay up later, and they can sleep in, but they can also have shorter sleeps. So, there's a chronobiology aspect that comes to it with regards to how our body actually falls asleep and wakes up. And there's a sex difference in that chronobiology.

• 1:28:05Steven Bartlett?

  Do men or women suffer more with jet lag?

• 1:28:07Dr. Stacy Sims?

  Women suffer more with jet lag.

• 1:28:10Steven Bartlett?

  And if so, why is that?

• 1:28:12Dr. Stacy Sims?

  Because if we're looking at our circadian rhythms and how long they are, like I said, melatonin peaks earlier for women than men, and we have a slightly different.

• 1:28:22Steven Bartlett?

  What does that mean, sorry, melatonin?

• 1:28:23Dr. Stacy Sims?

  So melatonin is what allows our body to actually get into sleep. And our wind down for that is melatonin production. So a lot of people will start to feel really sleepy at like four in the afternoon. It's just a natural occurrence. Our core temperature comes up, we start to have melatonin production. And for women, a melatonin peak for sleep to for sleep onset hits around nine PM on average. For men, it's about 10 or 11 PM because our circadian rhythms are different. So women are on a shorter side than men. So we're talking about jet lag. For women going east, it's a little bit easier because it's a shorter. For women going west, it's a little bit harder because it's longer. So there's a difference.

• 1:29:05Dr. Stacy Sims?

  Men will do better going west and worse going east. Women go better east than going west.

• 1:29:13Steven Bartlett?

  When it comes to food, I trust my gut and I trust Zoe, a business I'm an investor in and today's sponsor of this podcast. All the nutritionists I've spoken to have highlighted just how misleading information is out there when it comes to food. Take healthy halos. The claims you see on packaging that say things like low sugar and nothing artificial are often a sign of foods to avoid. Have you ever noticed a health claim on fresh fruit? You probably get my point. Understandably, there's loads of distrust out there. Who should you turn to for accurate information? I use Zoe, which is backed by one of the world's largest microbiome databases and most scientifically advanced at home gut health tests. Zoe gives you proven science whenever you need it. As a Zoe member, you'll get an at home test kit and personalized nutrition program to

• 1:29:57Steven Bartlett?

  help you make smarter food choices that support your gut. To sign up, visit Zoe.com and use my code Bartlett10 for 10% off your membership. That's Zoe.com code Bartlett10. Trust your gut. Trust Zoe.

• 1:30:13Steven Bartlett?

  Use this term chronobiology. I have no idea what that word means, but that's the biology of our circadian rhythm?

• 1:30:21Dr. Stacy Sims?

  Yeah.

• 1:30:21Steven Bartlett?

  Okay.

• 1:30:21Dr. Stacy Sims?

  Yeah, yeah.

• 1:30:22Steven Bartlett?

  And is there anything else that men and women should understand about our chronobiology? That's pertinent, making sure that we're high performing and healthy.

• 1:30:31Dr. Stacy Sims?

  Yeah, so this comes down to our hormone and pulses throughout the day. So we see that cortisol, which everyone talks about as being a bad thing, it's not a bad thing. We have a peak about a half an hour after wake up. And for women, we need to eat in order to dampen that peak. For men, it just naturally dampens. So you don't need the food to instigate dampening of that peak. We see a luteinizing hormone pulse in both men and women, but the amplitude of that pulse is greater in women because it's responsible for how our body responds to developing an egg so that it can be fertilized. We also see estrogen pulses again to pulse throughout the day and then throughout the week before we can come to one of those estrogen peaks.

• 1:31:17Dr. Stacy Sims?

  So our body is aligned for these pulses and we have a twenty-ish, twenty-four-ish hour clock. And within that, we have cellular clocks. So we have a cellular clock that's telling us to pulse luteinizing hormone every so often. We have an internal cellular clock that's telling estrogen to pulse every so often. And we can change that through differences in sleep, change that through our light wake time and through food intake.

• 1:31:47Steven Bartlett?

  How important is it to time our meals and be intentional about when we eat?

• 1:31:52Dr. Stacy Sims?

  It's pretty important if we're looking about how our clock is aligned.

• 1:31:57Steven Bartlett?

  Yeah.

• 1:31:57Dr. Stacy Sims?

  And how we are repairing while we're sleeping. Because if we're eating late and we've shifted everything late because people eat late, they go to bed, they wake up, they're not hungry. They don't dampen that cortisol peak for women. And then they don't sleep very well because if you are eating right before bed, your body is using parasympathetic response to digest instead of invoke really good sleep. So we see a lot of this circadian misalignment that's occurring. We see it a lot in shift workers. We see it a lot in our global society of staying up late and working and having screens. And the impact on metabolism is that it changes appetite hormones for women, where it will increase the craving for carbohydrates and the desire to eat more.

• 1:32:42Dr. Stacy Sims?

  And they don't ever feel full. For men, it's just a craving aspect. And so they'll eat according to cravings. It's called hedonistic eating rather than a true change in appetite hormones. So people who are having difficulty sleeping and difficulty changing body composition for overall health, we shift it. We're like, okay, we want to shift to be able to eat during the day and to have regular food at regular intervals so that our body has fuel to do what it needs during the day. We stop eating at dinnertime, which is around six or seven, have a good two to three hours before we go to bed so that when we do go to bed, all our parasympathetic responses can go into getting really good sleep architecture.

• 1:33:27Dr. Stacy Sims?

  So that means we get really good phases of sleep for optimal physical, mental recovery. Because if we have that, then we have better blood glucose control, so better insulin responses. We're able to have more energy during the day and all of our systems work better.

• 1:33:44Steven Bartlett?

  I had noticed something intriguing about me, which is when I wake up early to go to the airport. So say I have to wake up at like four AM to go to the airport. I am so hungry.

• 1:33:55Dr. Stacy Sims?

  Yeah.

• 1:33:56Steven Bartlett?

  And I've never understood why, because if I wake up at, say, nine AM, I don't wake up as hungry.

• 1:34:01Dr. Stacy Sims?

  Yep.

• 1:34:02Steven Bartlett?

  Why?

• 1:34:03Dr. Stacy Sims?

  Your brain is perceiving a stress. And this is that hedonistic where you're like, oh, my brain is like, I'm under stress and I need fuel. I need glucose.

• 1:34:12Steven Bartlett?

  So it thinks like a line has woken me up?

• 1:34:14Dr. Stacy Sims?

  Yeah.

• 1:34:15Steven Bartlett?

  Fucking hell, that makes so much sense. Honestly, it's so, it's so, it's always confused me because sometimes I have to wake up super early, so two, three AM to go get a plane or something. And when I get to the airport, I'm so hungry.

• 1:34:26Dr. Stacy Sims?

  Yep.

• 1:34:26Steven Bartlett?

  But like a day to day, what time is it? It's one PM and I haven't eaten yet. I know you're mad at me, but I haven't eaten yet because I don't want to eat before I do a podcast because then it's gonna like, it like messes with my articulation. So I can't get the words out my mouth.

• 1:34:41Dr. Stacy Sims?

  Okay.

• 1:34:42Steven Bartlett?

  That's, maybe that's bullshit. I'm saying this to someone that knows what they're talking about, but maybe there's something else I could eat. But I just find that if I eat something heavy, or if generally if I eat, the way that I've always rationalized it is all the oxygen's like going to my digestive system. Is that nonsense?

• 1:34:56Dr. Stacy Sims?

  That's nonsense.

• 1:34:57Steven Bartlett?

  Is it actually?

• 1:34:57Dr. Stacy Sims?

  Yeah.

• 1:34:58Steven Bartlett?

  So can I eat before I do a podcast?

• 1:35:00Dr. Stacy Sims?

  Yes, you can.

• 1:35:00Steven Bartlett?

  And it won't impact my ability to articulate myself?

• 1:35:02Dr. Stacy Sims?

  If you're really worried, then you can have like a protein shake or protein water. You could sip protein water while you're having a podcast. So then you're getting amino acid circulating, your hypothalamus is like, sweet, okay, we're all good to go. But I hear you because I don't like to have a lot of food in my stomach, but I'm going to be concentrating a lot or trying to articulate. So I eat things that are high in protein, but easy to digest.

• 1:35:23Steven Bartlett?

  Okay.

• 1:35:24Dr. Stacy Sims?

  Try that.

• 1:35:24Steven Bartlett?

  So like protein water, a protein shake would be a good idea before.

• 1:35:27Dr. Stacy Sims?

  Or hard boiled eggs.

• 1:35:28Steven Bartlett?

  Hard boiled eggs, okay. Okay. Let's talk about menopause then.

• 1:35:31Dr. Stacy Sims?

  Yeah.

• 1:35:32Steven Bartlett?

  Starting with perimenopause.

• 1:35:34Dr. Stacy Sims?

  Yeah.

• 1:35:35Steven Bartlett?

  You've got a smile on your face.

• 1:35:36Dr. Stacy Sims?

  Oh, it's something that I'm really excited is coming into conversations now because three years ago, no one would say the word. I knew we had made it as women in society when the nightly news was talking about menopause. So let's go. I'm excited.

• 1:35:49Steven Bartlett?

  One thing I saw, which was quite an interesting observation, is in the UK this year on Apple, the most shared podcast episode in the whole country of all podcasts was a conversation I had about menopause.

• 1:36:02Dr. Stacy Sims?

  Nice.

• 1:36:03Steven Bartlett?

  And.

• 1:36:04Dr. Stacy Sims?

  Congratulations. That's awesome.

• 1:36:05Steven Bartlett?

  It gets even better. And in the US, the most shared podcast episode of all podcasts in the US on Apple

• 1:36:15Steven Bartlett?

  was the same guest on Mel Robbins podcast talking about menopause. I go, that's incredible and also crazy that in both countries, the number one most shared podcast episode was the same guest talking about the same topic.

• 1:36:30Dr. Stacy Sims?

  Yep.

• 1:36:31Steven Bartlett?

  That doesn't surprise you?

• 1:36:32Dr. Stacy Sims?

  Nope.

• 1:36:33Steven Bartlett?

  Why?

• 1:36:34Dr. Stacy Sims?

  Well, I know this guest and she's very good at articulating, but also we have seen this upsurge of. Women like myself, my age group, put myself out there. We all grew up on the understanding that we were women. We were a little bit different from men, but no one told us about menopause. And now, all of a sudden, there are these extreme changes that are going on. And people are like, what's going on? And if I were to take a typical case scenario of a woman who's in her 40s and goes to a doctor and goes, you know what? I can't sleep. I am trying to exercise, but I'm so tired.

• 1:37:19Dr. Stacy Sims?

  I can't do it. My body is changing and I just don't know what's going on. The general response to her three years ago would have been, well, look, you're a woman in her 40s who's highly stressed. You have kids on one side. You have older parents on another. You're trying to, you're right in the middle of your career. You have a really busy life. Here's an SSRI for anxiety and depression is going to help you sleep. But now with all the conversations that have been going on, a woman in her 40s will go to a GP and for the most part will be told, well, you're in your 40s. It might be perimenopause. And this is such a relief to so many women because they're not being gaslit anymore.

• 1:38:03Dr. Stacy Sims?

  They're not being told that what they're feeling isn't true. It's just something to do with stress. Now they're being told, you know what? All your systems in your body are being affected because your sex hormones are changing. So remember puberty? When everything was changing and no one wants to live through puberty anymore? You're on the other side of that. You're in reverse puberty where all of your hormones are starting to downregulate. So every system in your body is being affected. Let's unpack it. Let's see what's going on. So when Mary Claire comes on and talks about menopause as an MD and talks about all the things that she's seeing in her clinic. Women are like, that's me. Now I understand I'm not alone.

• 1:38:45Dr. Stacy Sims?

  And that's the power that's coming through all of these conversations and all of these groups like Naomi Watts Swell Group, right? They're talking about menopause. So now women are listening and keying in and going, wait a second, there actually are things that are occurring to me and I can get information, which is why these podcasts are taking off. Because now women are like, I'm not just crazy. There are actually things happening to me and people understand that. Now what can I do to help myself? Because it isn't being taught in med school. A lot of the doctors that are out there are getting information because they are seeking it out themselves and looking to people like Mary Claire and

• 1:39:27Dr. Stacy Sims?

  other like Louise Newsom in the UK, who are actually talking about and saying, these are the things that are happening and these are the things that we know that we can do.

• 1:39:36Steven Bartlett?

  Gosh, it's a shame, isn't it? It's a shame that there must have been so many women over the years that went to their doctor and got really bad advice.

• 1:39:42Dr. Stacy Sims?

  Yeah.

• 1:39:42Steven Bartlett?

  And were given antidepressant medications and stuff like that.

• 1:39:45Dr. Stacy Sims?

  Well, the other side is women who are in their reproductive years who have something like PCOS or endometriosis, or they're having irregular periods and they're put on an oral contraceptive pill. Because the doctors don't understand that there are other things that are going on that will cause a misstep in menstrual cycle. So I get frustrated when teenage girls go to a doctor with irregular cycles and they're handed OCs like Skittles. It's like, that's not appropriate either. We have to actually understand what's going on. We know that there's irregularity in a menstrual cycle. Until people are around three years post the onset of their first menstrual cycle. It's not unusual. An OC is not the answer. If someone's still having irregularity, we have to look at lifestyle

• 1:40:29Dr. Stacy Sims?

  and say, hey, what's going on? They're having really heavy menstrual bleeding? It's not about using an OC to control it. Let's look and see why is that happening? Maybe we use an IUD or maybe we use some other medication to help. But there's a lot of things that are not taught in med school that women are having to find out for themselves. And so when we listen to podcasts and we're hearing information from medical doctors who now have a, like a vocal aspect of being able to touch so many people, it resonates. So now doctors are trying to find that information if they have the time. But we know the healthcare systems in most countries, doctors are so pressed for time, they don't have that opportunity.

• 1:41:06Steven Bartlett?

  So let's talk about peri-menopause.

• 1:41:08Dr. Stacy Sims?

  Yeah.

• 1:41:09Steven Bartlett?

  What do I need to be thinking about? What age group typically is perimenopause? I guess it can be a wide spectrum, but when does that typically start? And how do I need to be thinking about my nutrition and exercise in that phase?

• 1:41:21Dr. Stacy Sims?

  So around age thirty five, up to, I think they say now the average age of menopause is fifty two years old.

• 1:41:29Steven Bartlett?

  Okay.

• 1:41:30Dr. Stacy Sims?

  So what's happening in that fifteen to seventeen year span is you're having such a change in the ratio of estrogen and progesterone. Early days, a lot of it appears as I'm not adapting to my training. It's not working well. I'm putting on more body fat. I'm becoming squishy. I'm not sleeping well. I'm having lots of mood changes. It must be, this is why a lot of doctors say, oh, it's because you're busy and stressed out. Here's a serotonin reuptake inhibitor, but no, it's changes in the ratios. How can we dial it in? We look at menstrual cycles and is it becoming shorter or longer? What's our bleed phase?

• 1:42:10Dr. Stacy Sims?

  We get into our mid to late forties, it's very apparent because there are a lot of different changes that are occurring. We're seeing a change in our blood lipids. There's an increase in our low density lipoprotein, which is the quote bad cholesterol. Even if a woman's never had an issue with it, now all of a sudden she's having issues with her cholesterol. We see A1C coming up, which is a marker for diabetes, pre-diabetes, without any real change in what they're doing. Other than the fact that their exercise isn't working, their sleep is a little bit disrupted and their body composition is completely changing. And when we're looking at what's happening, we see that decrease in gut microbiome diversity because we don't have as many sex hormones.

• 1:42:54Dr. Stacy Sims?

  So that impacts serotonin, that impacts vitamin production, that impacts parasympathetic drive.

• 1:43:01Dr. Stacy Sims?

  And we're also seeing a misstep in the way liver is reading fat and fat circulation. So we're seeing free fatty acids that are coming around. And because we don't have as much estrogen, we don't have as much anti-inflammatory responses. So we can't pull as many free fatty acids into the mitochondria and the skeletal muscle to be used as fuel. So they circulate and the liver has a signal that goes, we're going to change that free fatty acid into what we call esterified fatty acid, which then gets stored as visceral fat. And visceral fat is that dangerous fat that gets stored around the organs, which is why women start to get like a menopause or develop a lot of abdominal adiposity. So people will start seeing this and going, I don't understand what's going on.

• 1:43:45Dr. Stacy Sims?

  Over the past six months, I put on 10 pounds or, or I put on four stone, right? What's going on? My training is not working. Become very despondent. And if they don't know they're in perimenopause, then they don't know that that's what's happening.

• 1:43:58Steven Bartlett?

  And how can they find out if they are?

• 1:44:00Dr. Stacy Sims?

  Well, it's really symptomatic because we can't use blood tests. There isn't a definitive blood test to say, hey, you're a perimenopausal. You have to have a, a history of everything of getting blood tests like every week and no one does that. So we have to go on symptomology. It's really using the socio-cultural aspect of how a woman is experiencing life with her symptoms. And really listen and say, okay, well, here are the things that are going on. And we try to instigate non-hormonal options. There's exercise, there's lifestyle. And then if all else is really going to shit, then we can look at using some menopause hormone therapy. Just like we were talking about Ozempic being a tool.

• 1:44:45Dr. Stacy Sims?

  So hormone therapy can also be a tool.

• 1:44:48Steven Bartlett?

  Does it matter my pre-existing health when I approach menopause? If I'm, if I've got more weight on my body, is that going to impact the amount of symptoms that I experience of menopause?

• 1:44:59Dr. Stacy Sims?

  It can, yeah, it can. We see that there is a greater incidence of vasomotor symptoms or hot flashes for women who have a greater amount of body fat. We also see that if you have more lean mass, then you're going to have less of an incidence of insulin resistance. So body composition has a huge play in symptomology. And then you also have to look at what your mom went through. Because if your mom had a really, really horrible time with lots of azomotor symptoms and body composition change, there's a genetic link. Doesn't necessarily mean that you're going to experience the same thing, but you have a greater predisposition to having more severe symptomology.

• 1:45:42Steven Bartlett?

  How should I be thinking about exercise as I'm going through my menopause journey?

• 1:45:47Dr. Stacy Sims?

  So we look, as I said earlier, exercise is a really good stress for adaptive change. So when we start getting into all these ratio shifts of estrogen and progesterone, we can't rely on our hormones to create those adaptive changes. And so what I mean by that is like estrogen is responsible for muscle protein synthesis and and strength and power for women. Progesterone and estrogen are responsible for bone, bone growth, bone density. We can't rely on our hormones for that anymore. We have to look for an external stress. So this is where exercise comes in. So we're looking specifically at how to invoke a stress to change our insulin sensitivity. In other words, improve our blood glucose control. We need to do proper high intensity work.

• 1:46:32Dr. Stacy Sims?

  So that's sprint interval or it's true high intensity work to create a stress that's high enough to have the brain say, hey, this is a really, really, really strong stress. I need to invoke changes within the skeletal muscle to be able to store more glucose. I also need to invoke more changes in the mitochondria so that it can use and store more free fatty acids. And I'm going to have more myokine released from the skeletal muscle to tell the liver, don't estrophylate those fatty acids. I want to use them at rest so we don't get visceral fat gain.

• 1:47:07Steven Bartlett?

  So HIIT workouts?

• 1:47:08Dr. Stacy Sims?

  Yeah.

• 1:47:09Steven Bartlett?

  plyometrics?

• 1:47:10Dr. Stacy Sims?

  Yeah.

• 1:47:10Steven Bartlett?

  Which is jumping and stuff?

• 1:47:12Dr. Stacy Sims?

  Yeah.

• 1:47:13Steven Bartlett?

  Resistance training?

• 1:47:14Dr. Stacy Sims?

  Absolutely.

• 1:47:14Steven Bartlett?

  Weights, right?

• 1:47:15Dr. Stacy Sims?

  Yeah. But specific to the type of weights that you're doing.

• 1:47:19Steven Bartlett?

  What about frequency of training and how long I train for?

• 1:47:22Dr. Stacy Sims?

  We want to think about less volume and more quality.

• 1:47:26Steven Bartlett?

  Okay.

• 1:47:26Dr. Stacy Sims?

  So we're not going to the gym for an hour and a half every day. We're looking at doing short, sharp, high-intensity cardio, or we're looking at doing power-based resistance training three times a week, and the cardio can be two to four times a week.

• 1:47:41Steven Bartlett?

  Why shorter durations of training?

• 1:47:44Dr. Stacy Sims?

  We're looking at intensity. So if we're doing long, slow stuff, or we're doing moderate-intensity zone-two stuff, that's not really going to create the kind of stress that we need to invoke change.

• 1:47:55Steven Bartlett?

  What about saunas and stuff like that?

• 1:47:57Dr. Stacy Sims?

  Yeah, absolutely. We see that women who go into the sauna get better control over things like hot flashes, because it's all about temperature and temperature control. So if the blood going through the brain is really hot, it understands, hey, this is what hot is, and can then have subsequent peripheral changes for controlling heat and understanding heat, as well as sensual changes to understand heat.

• 1:48:23Steven Bartlett?

  And what about food through menopause? Is there a specific diet that I should be thinking about for menopause?

• 1:48:30Dr. Stacy Sims?

  We want a higher protein intake, of course, because as we get older, we become more anabolically resistant to protein. So that means our body isn't responding as much to the amino acids. So we need a higher dose to invoke muscle protein synthesis and bone regeneration, nerve regeneration. Also, knowing that the recommended daily allowance that's out there for protein, especially for women, is based on sedentary older men. So it's not really adequate for what we're looking for. So we want higher incidence of protein at regular intervals across the day, and again, taking care of that gut microbiome. So we want a lot of colorful fruit and veg. That also helps with blood glucose control,

• 1:49:13Dr. Stacy Sims?

  as well as creating that diversity, so that we are able to reduce the amount of bacteria that is responsible for storing body fat. We want to have that great amount of diversity of gut microbiomes to, or great diversity of the gut microbiome to have more of the bacteria that says, hey, you know what? We want more lean mass. We want to have less body fat.

• 1:49:39Steven Bartlett?

  I noticed earlier on when you talked about hormone therapy, you referred to it as menopausal hormone therapy as opposed to

• 1:49:47Dr. Stacy Sims?

  Hormone replacement.

• 1:49:48Steven Bartlett?

  Therapy.

• 1:49:49Dr. Stacy Sims?

  Yeah.

• 1:49:49Steven Bartlett?

  Most people say HRT.

• 1:49:51Dr. Stacy Sims?

  Right, right.

• 1:49:52Steven Bartlett?

  Why do you?

• 1:49:53Dr. Stacy Sims?

  Say something different.

• 1:49:54Steven Bartlett?

  Yeah.

• 1:49:55Dr. Stacy Sims?

  I got a lot of my chops in menopause work through the Women's Health Initiative. And I'm not going to apologize for that cohort because this study was designed to look at older women going through perimenopause or going through menopause and does it work? So there's a whole issue around WHI and other things. But when we look at specifically women who are going through menopause or perimenopause into menopause, we're not looking to replace hormones. We're looking at a therapy to attenuate change. If we're looking at hormone replacement, that could be thyroid. That could be premature ovarian failure that we need to have some estrogen, progesterone.

• 1:50:39Dr. Stacy Sims?

  We're looking at menopause and perimenopause in itself. We're looking at using a hormone dose that is a very low physiologic level so that we don't have symptomology. So the body is not going to have vasomotor symptoms and is not going to have mood changes and is not going to really have an incredible amount of body composition change. If we're replacing hormones, people have the idea that it's going to be the same physiologic level as when we are in our reproductive years, and that's not the case.

• 1:51:13Steven Bartlett?

  Is there also a bit of an underlying notion that women are using these hormones to as a way to stay young? And when you say replace, you're kind of implying that they're fighting against something?

• 1:51:24Dr. Stacy Sims?

  Yep, that we are replacing our hormones to stay young and be in our reproductive years. So we look at Western society and I like to use the cast of Friends as an example from, you know, 90s to now, right? And we see that the cast of Friends women all have a certain look. That they've had to maintain in order to be viable on Hollywood, which means that they're thin, they have good body composition, they don't have any wrinkles, they have really good lustrous hair. And that's the image that women have now of how they're supposed to age. Where men, not so much. We see the images of men who are aging, becoming more demure, I guess. They have gray hair, they have some wrinkles, they're very distinguished. And that's the image we have of men aging.

• 1:52:09Dr. Stacy Sims?

  There's a huge disconnect in society. So when women start to experience perimenopause, it's a definitive point of aging. And people are afraid to age. Everyone's afraid to age for the most part. The idea of aging gracefully or embracing it hasn't quite gotten to the mainstream. So when someone's like, here's some hormones to replace so you can stay young. People are like, great. But we look at the research and it's not about staying young. It's about slowing the rate of change that's so severe that creates quality of life distress. And we also see that the research isn't there for maintaining brain integrity to prevent dementia, which is the other thing that's floating around. It's not there.

• 1:52:54Dr. Stacy Sims?

  There's no evidence to show that taking hormone therapy is going to stop dementia. So there's lots of things out there that's a disconnect. And trying to say it's menopause hormone therapy is one way of getting people to understand that it's not an anti-aging agent. It's something to help with this phase of life. And to help get through so that we don't have severe changes to our daily life and who we are as a person.

• 1:53:22Steven Bartlett?

  Is there anything else that we need to talk about as it relates to menopause? Just want to make sure we've

• 1:53:26Dr. Stacy Sims?

  Covered it all?

• 1:53:27Steven Bartlett?

  Covered it all.

• 1:53:29Dr. Stacy Sims?

  It gets better on the other side. I think that's something people don't talk about. Is perimenopause is such the conversation now with all the conversations around hormone therapy, exercise, lifestyle, but no one talks about the other side. Once you've gotten through perimenopause, do my joints stop hurting? Do I stop having all these sleep interruptions? Do I stop having to worry about my bones? And if you're putting in the right lifestyle changes to maintain bone health, yes, on the other side, everything becomes a new normal without the pain and dysfunction. Because it's the shift in hormones that's creating so many different issues with every system of the body.

• 1:54:11Dr. Stacy Sims?

  So if we get through this with really good interventions for preventing or attenuating the changes that are happening, the other side is much better.

• 1:54:22Steven Bartlett?

  And for women with PCOS or endometriosis, is there anything that they need to be thinking about as it relates to exercise or nutrition?

• 1:54:28Dr. Stacy Sims?

  Yeah, so there's, I guess, a huge misstep in the understanding that endometriosis is an inflammatory response. Yes and no, there's some more emerging evidence that it could be a bacterial or a viral cause. But with regards to endometriosis, we see that if you're able to use some cold water therapy, for the most part, or a cold water plunge, around the time that you think about ovulation, where after ovulation you have endometrial growth, it reduces the total inflammatory response so that the endometrial lining doesn't grow as much, so you don't

• 1:55:11Dr. Stacy Sims?

  have as much growth of endometrial tissue outside of the uterus.

• 1:55:15Steven Bartlett?

  Okay.

• 1:55:16Dr. Stacy Sims?

  So we're looking at how do we stop that extra growth? We can use environmental cues to help with that. So that's that cold therapy. If we look at PCOS, it's all about a higher androgen count, and we have more insulin resistance. And how we're training for exercise is all about how do we control that insulin resistance? So we look at high intensity, we look at using resistance training. So women who have PCOS, they have irregular cycles, so we can't use the menstrual cycle as an indication of stress. So we have to look at things like heart rate variability, we have to look at properly putting in intensity and resistance training to work with blood glucose levels to, again,

• 1:56:01Dr. Stacy Sims?

  attenuate some of the symptomology that comes with PCOS.

• 1:56:05Steven Bartlett?

  What is the most important thing we haven't talked about that we should have talked about?

• 1:56:10Dr. Stacy Sims?

  That this conversation isn't just for women. I'm very grateful that you're very excited about the menstrual cycle. But I think a lot of people kind of tune out when we start to hear conversations about women and conversations about sex differences. But it's for everybody because if we're going to push forward and understand how we need to do research to improve the health of women and men, then it's a combination in the conversation. So I, yeah, I'm very appreciative to men who come into the conversation and men who are in the room and very appreciative of you for having these conversations because then it pushes it out and makes it normal across the board.

• 1:56:53Steven Bartlett?

  Yeah, and the reason I I have these conversations is because it's a lot of my conversations at home with my partner. We spend so long talking about her menstrual cycle and about when she's ovulating. And she talks to me a lot about how she's feeling because of that and certain things we should be doing, even when we're thinking about like how to spend the weekend. It's often decided through the context of like her cycle. And then obviously, we're trying to, we're in the phase of life where we're going to try and have kids now, so we're thinking a lot about it there. But then just more broadly, you know, if something is having such a significant impact on a woman's life, which I think it does, I think it does have significant impact, things like menopause and the menstrual cycle generally, then I'm going to interface with women my whole life. If I have a daughter, I have sister, I have mom, I have a partner.

• 1:57:38Steven Bartlett?

  So if I can better understand them because I understand how their body is working, then we're going to have more successful relationships. And frankly, a year ago, I didn't even know what menopause was. So

• 1:57:51Dr. Stacy Sims?

  Yay.

• 1:57:51Steven Bartlett?

  To be fair, I didn't even know what a menstrual cycle really was a year ago. I knew that women had periods, but I kind of told you with great confidence that different things happen throughout the cycle and that it was 28 days long. I really had no idea and I'm like 32 years old and I don't really care about admitting that people, but I don't really care because I know there's a lot of people out there that feel the same way. And and we're like not allowed to admit that because then you get people attack you or whatever, but who cares?

• 1:58:17Dr. Stacy Sims?

  I had a PhD student who came up to me and he's like, My partner has something to tell you and it's gonna come through me. I was like, okay, what is it? He said, she said to tell you that I know more about the menstrual cycle than she does.

• 1:58:31Steven Bartlett?

  Really?

• 1:58:32Dr. Stacy Sims?

  Awesome. Cause he was looking at women in the heat versus men in the heat. So he had to understand the menstrual cycle and how all of that came. And then that upskilled her. So it came in the opposite. Instead of her trying to upskill him, he upskilled her.

• 1:58:46Steven Bartlett?

  We don't really learn about this stuff in school.

• 1:58:47Dr. Stacy Sims?

  No.

• 1:58:48Steven Bartlett?

  Nobody ever told me about it in school. Do women learn about it in school?

• 1:58:50Dr. Stacy Sims?

  Not anymore. It's been cut. All the health programs and everything have been cut. So, yeah, it's really, like I give talks and the rooms get full of parents who want to know what's happening. Like I give talks for young kids who are, you know, surf life saving or whatever, just explaining it all. And then I'll get questions from women. Well, what about perimenopause? What about menopause? What about IUD? What about this? What about that? Because it's not taught. And it's, it's, um, yeah, it's really scary.

• 1:59:21Steven Bartlett?

  All of the subjects we've discussed today are in these two excellent books. Well, there's even more in the books, but all the subjects that I touched on, pretty much all of them are in either of these two books. Next Level, which is your guide to kicking ass, feeling great and crushing goals through menopause and beyond. And your book Raw, which is match your food and fitness to your unique female physiology for optimal performance, great health and a strong body for life. I would not have been able to read that if I had eaten today.

• 1:59:45Dr. Stacy Sims?

  Maybe if you had had a protein shake, you would have been able to read it.

• 1:59:48Steven Bartlett?

  Even better, maybe. We have a closing tradition on this podcast where the last guest leaves a question for the next guest, not knowing who they're going to be leaving it for. And the question that's been left for you is if you have children, what is the most important message you would pass on to them? If you don't, then what is the most important message you would have passed yourself as a child?

• 2:00:10Dr. Stacy Sims?

  I have a daughter and the most important messaging that I keep giving to her is to be empowered, to ask questions and to be empowered. And she'll often say, well, what does that mean, mom? I'm like, you have a question? You ask it. Don't be afraid to ask it because if you don't know, you don't know. So society is very changing. I want you to be empowered and be educated to and have the confidence to ask questions.

• 2:00:35Steven Bartlett?

  Stacey, thank you so much for the work that you do. It's incredibly important and it's so wonderful that people are shining a light on some of these differences between men and women. Because yeah, like me and my partner trained together. We work out, we it's a big part of our relationship in life. And now, having studied your work, which was absolutely fascinating to me, because it was again, it was a first for me to understand that there was any differences in these sort of things that have been pushed on us in term in culture, in terms of exercise, nutrition, cold plunges, fasting, etc. Absolutely fascinating. But it's been a huge conversation now between me and her. We were talking before I came on air about this. And it's really turned the lights on. And it's actually made a lot of things make sense.

• 2:01:10Dr. Stacy Sims?

  Excellent.

• 2:01:11Steven Bartlett?

  A lot of things make sense that we were pondering. So thank you so much for the work that you do. And I highly recommend everybody goes and checks you out.

• 2:01:16Dr. Stacy Sims?

  Thanks so much. I appreciate it. Are you gonna make her eat before you go training now?

• 2:01:20Steven Bartlett?

  Well, I don't know. I actually did send her a screenshot of that, of that particular part. Because we have the same routine, especially on like the weekends when we're together. We get up, we have the coffee, then we go to the gym.

• 2:01:31Dr. Stacy Sims?

  Yeah.

• 2:01:32Steven Bartlett?

  And we train, and then we go and try and find something to eat after. So.

• 2:01:36Dr. Stacy Sims?

  She could have fresh coffee.

• 2:01:38Steven Bartlett?

  Yeah, maybe that's a good idea. Maybe. I'll leave it up to her. I'd listen, I'm never gonna tell her what to do. So I just sent her the research.

• 2:01:44Dr. Stacy Sims?

  Okay. Encourage her.

• 2:01:46Steven Bartlett?

  I was like, look at this, you'll find this interesting. So we'll see. Thank you so much, Stacey.

• 2:01:54Steven Bartlett?

  Do you know that 80% of New Year's resolutions fail by February? It's because we focus too much on the end goal. And we forget the small daily actions that actually move us forward. Those actions that are easy to do are also easy not to do in life. It's easy to save a dollar. So it's also easy not to. Making one small improvement each day, one tiny step in the right direction, has a big difference over time. And that is the 1% mindset, which is why we created the 1% Diary, a 90 day journal designed to help you stay consistent and focus on the small wins and make real progress over time. It also gives you access to the 1% community, a space where you can stay accountable, motivated, inspired, along with many others on the same journey. We launched the 1% Diary in November and it sold out.

• 2:02:37Steven Bartlett?

  So now we're doing a second drop. Join the waitlist at thediary.com and you'll be the first to know as soon as it's back in stock. I'll put the link below.