Essentials: How to Exercise for Strength Gains & Hormone Optimization | Dr. Duncan French

In this Huberman Lab Essentials episode, my guest is Dr. Duncan French, PhD, the vice president of performance at the UFC Performance Institute and a world-class performance specialist. We explain how resistance training and acute stress impact hormones and outline specific weight training protocols to increase testosterone to support strength and hypertrophy. We also discuss how to use cold and heat exposure to enhance recovery and performance. Finally, we explain how to match nutrition to training goals and improve metabolic flexibility. Read the episode show notes at hubermanlab.com. Thank you to our sponsors AGZ by AG1: https://drinkagz.com/huberman Function: https://functionhealth.com/huberman Eight Sleep: https://eightsleep.com/huberman Timestamps (0:00) Duncan French (0:20) Resistance Training & Hormones, Testosterone, Men vs Women (4:32) Increase Testosterone & Resistance Intensity, Tool: 6 x 10 Protocol (7:53) Rest Periods & Metabolic Stimulus (9:26) Sponsor: Function (11:07) Weekly Training Sessions, Varied Intensity & Volume, Recovery (12:34) Short-Term Stress, Testosterone & Performance, Mindset (15:05) Deliberate Cold Exposure, Mindset & Recovery (17:14) Tool: Cold Periodization, Recovery & Goals (22:12) Sponsor: Eight Sleep (23:53) Sport, Skill Training & Quality Movement, Fatigue; Mental Fatigue (26:19) High-Intensity Training & Carbohydrates; Exogenous Ketones; Ketogenic Diet (29:32) Metabolic Efficiency, Carbohydrates & Fat Stores, Tool: Nutrition Periodization (32:45) Sponsor: AGZ by AG1 (34:14) Heat Adaptation, Sauna, Sweating (37:14) Training, Nutrition & Adaptations, Tool: 12 Week Program (39:06) Acknowledgements Disclaimer & Disclosures 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.

• 0:00Andrew D. Huberman?

  Welcome to Huberman Lab Essentials, where we revisit past episodes for the most potent and actionable science-based tools for mental health, physical health, and performance. I'm Andrew Huberman, and I'm a professor of neurobiology and ophthalmology at Stanford School of Medicine. And now, my conversation with Dr. Duncan French. Duncan French, great to see you again.

• 0:22Speaker 01

  Likewise, likewise. Thank you. I don't often have many Stanford professors in the Performance Institute, so I'm really excited.

• 0:29Andrew D. Huberman?

  Oh, well, this place is amazing, and you have a huge role in making it what it is. I found dozens of papers on how weight training impacts hormones, and your name's on all of them. What is it about engaging motor neurons under heavy loads sends a signal to the endocrine system, "Hey, release testosterone"? I've never actually been able to find that in a textbook.

• 0:54Speaker 01

  Yeah, I mean, I think it's a stress response, right? It's mechanical stress, and it's metabolic stress. And these are, you know, downstream regulation of testosterone release at the gonads comes from many different areas. You know, my work primarily looked at catecholamines and sympathetic arousal.

• 1:13Andrew D. Huberman?

  So things like epinephrine adrenaline?

• 1:14Speaker 01

  Correct, yeah. Epinephrine adrenaline, noradrenaline, how they were signaling, the signaling cascade using the HPA axis, releasing cortisol, and then, you know, looking at how that also influenced the adrenal medulla to release androgens, and then signaling that at the gonads.

• 1:35Andrew D. Huberman?

  That raises an interesting question. So in presumably weight training in women, people who don't have testes, also it increases testosterone? And is that purely through the adrenals? When women lift weights, their adrenal glands release testosterone?

• 1:48Speaker 01

  Absolutely. I mean, that is the only area of testosterone release for females. And yes, it's the same downstream cascade. Obviously, the extent to which it happens is significantly less in females. But that's how, there's good data out there that shows, you know, females can increase their anabolic environment, their internal anabolic milieu, using resistance training as a stressor. And then they Get the consequent muscle tissue growth, you know, whether it's tendon ligament adaptations, you know, the beneficial consequences of resistance training, which is driven by anabolic stimuli.

• 2:21Andrew D. Huberman?

  Yeah, I have two questions about that. The first one is something that you mentioned, which is that the androgens, the testosterone comes from the adrenals under resistance loads in women. Is the same true in men? I mean, we hear that the testes produce testosterone when we weight train. But do we know whether or not it's the adrenals or the testes in men that are increasing testosterone?

• 2:40Speaker 01

  Yeah, I think.

• 2:41Andrew D. Huberman?

  More both, a little bit from each?

• 2:42Speaker 01

  The field is divided presently in as much as understanding the acute adri- the acute adrenergic response in terms of, you know, anabolic response to exercise in an acute phase and the exposure to, you know, a stimulus that is stress driven, which might be partly from the adrenal glands, partly from the gonads versus a longitudinal exposure to anabolic environments, which is primarily driven by, obviously, the gonads and the release, the endocrine environment from testosterone release at the gonads. So the field is split in terms of how exercise is promoting hypertrophy, you know, muscle tissue growth and whether that is very much an adrenal stimuli

• 3:27Speaker 01

  or if that's significant enough in these acute responses versus the longitudinal exposure to just elevated basal levels of anabolic testosterone, habitual levels.

• 3:37Andrew D. Huberman?

  And then you mentioned that testosterone can have enhancing effects, growth effects on tendon and ligament also. You don't often hear about that. People always think, you know, testosterone muscle. But testosterone has a lot of effects on other tissues that are important for performance, it sounds like.

• 3:54Speaker 01

  Yeah, absolutely. I mean, the testosterone hormone is, I mean, listen, there's androgen receptors on neural tissue, on neural axons.

• 4:02Andrew D. Huberman?

  Pretty much everywhere.

• 4:03Speaker 01

  Exactly. So, you know, the binding capacity of testosterone and influence in different tissues within the body, I touched on, you know, muscle tissue, but, you know, the ligaments, the tendons, even bone to some extent, you know, testosterone is potential to influence that in terms of removing osteopenic kind of characteristics, et cetera. So, yeah, it's a, it's a, it's a magic, a magic hormone, let's say, with many, many end impacts in terms of adaptation.

• 4:32Andrew D. Huberman?

  Could you say that there's a, there are some general principles of training that favor testosterone production in terms of that, that somebody who's not an elite athlete could use, who's trying to use weight training to build or maintain muscle?

• 4:45Speaker 01

  Yeah.

• 4:46Andrew D. Huberman?

  Lose body fat, so body recomposition and/or stay strong and healthy for sport of a different kind?

• 4:52Speaker 01

  Testosterone is really stimulated by an intensity factor and also a volume factor. Now, growth hormone is a little bit different. That's largely driven by an intensity factor alone. If you look at many of the exercise interventions that we use to try and investigate and interrogate testosterone, it was, it was usually, you know, a six by 10 protocol. So six sets of 10 repetitions, which is, you know, it's quite a large, you know, 60 repetitions is quite a large volume for a, a single exercise. And that was usually pitched at about 80% intense of a one repetition max intensity.

• 5:26Andrew D. Huberman?

  Okay, so 80% of the one rep max, six, six sets of 10 reps separated by rest of?

• 5:31Speaker 01

  Two minutes.

• 5:32Andrew D. Huberman?

  Two minutes, which is actually pretty fast.

• 5:34Speaker 01

  Yes.

• 5:34Andrew D. Huberman?

  At least to me.

• 5:35Speaker 01

  It is.

• 5:35Andrew D. Huberman?

  Anytime you see these two to three minutes, when you're actually watching the clock, those two minute rest periods go by pretty fast.

• 5:40Speaker 01

  By the third, fourth set, you're dying for more, yeah.

• 5:43Andrew D. Huberman?

  Yeah.

• 5:43Speaker 01

  We formulated that kind of exercise protocol to really target, you know, the, the release of testosterone and try and drive up these anabolic environments to study the, you know, the endocrine, you know, consequences. But I think that's, that's, that's the type of protocol that is most advantageous for driving anabolic environments.

• 6:03Andrew D. Huberman?

  And that was it for the workout?

• 6:05Speaker 01

  Yeah, I mean, we, we would do that in a back squat. So, you know, multi-joint, you know, challenging exercise, multi-muscle, multi-joint, 80% loads of, of your one repetition max, and then six by 10. We did play around with, you know, your classic German volume type 10 by 10 kind of protocols. But they were just unsustainable at that 80%. The, the key to what we also did was we always adjusted the loads to make sure that it was 10 repetitions that were sustained. So if the load was too, too high and an athlete or a participant had to drop the weight on, on the sixth repetition, we would unload the bar and make sure they completed the 10 repetitions.

• 6:45Andrew D. Huberman?

  I see.

• 6:45Speaker 01

  Bringing me back to the point of it's an intensity and a volume derivative that, that is going to be most advantageous for testosterone release.

• 6:52Andrew D. Huberman?

  So that sort of hints at the possibility that the thresholds for going from a workout that increases testosterone to a workout that diminishes testosterone is actually a pretty narrow margin.

• 7:03Speaker 01

  Yeah, and I think it comes back to that intensity factor then, you know, what we saw with that 10 by 10 protocol really sees pretty significant drop offs in the load. And again, we're trying to stimulate with intensity, with mechanical strain through intensity, as well as metabolic strain through volume. And I think that's, that's the paradigm that you've got to look at is that the mechanical load has to come from, you know, the, the actual weight on the bar and the volume is the metabolic stimulus. How much are we driving lactate? How much are we driving, you know, glycogenolysis in, in terms of that type of energy system for, you know, executing a 10 by 10 protocol? And what we often saw was just a significant reduction in the intensity capabilities of an athlete to sustain that.

• 7:47Speaker 01

  So we shortened the volume to try and maintain the intensity.

• 7:52Andrew D. Huberman?

  Is there any evidence that training slowly can offset some of the negative effects of doing a lot of volume?

• 7:57Speaker 01

  The rest is often the consideration that's overlooked out there in general population and in many sporting environments, you know, that the rest is, is as important a programming variable as the load and the intensity, the intensity, the load, the, the volume, et cetera. If you extend the, the duration of your rest periods, what you're ultimately doing is influencing that metabolic stimulus again. You're allowing the flushing of the body, the removal of waste products, you know, lactate to be, you know, removed via, from, from the body and then the metabolic environment is reduced.

• 8:29Andrew D. Huberman?

  So if I, if I understand correctly, you want to create a metabolic stress.

• 8:33Speaker 01

  Absolutely.

• 8:34Andrew D. Huberman?

  So I could, I could in theory do a 45 or 60 minute session where I pack in more, more work per unit time. I'm not going to be able to quote unquote, perform as well. I won't be able to lift as much.

• 8:46Speaker 01

  Yeah.

• 8:46Andrew D. Huberman?

  I'm going to have to, you know, unweight the bar between sets or maybe even during sets if I have someone who could do that. But it sounds like that's the way to go. So it's got to be, so this, the old adage of high intensity, short duration is probably the way to go.

• 8:59Speaker 01

  Correct. And, and, and, you know, in, in layman's terms, if the The same objective, the same training goal is just muscle tissue growth. And we're not talking about maximal strength or any of those type of parameters. We're just talking about growing muscle. If there's an athlete A and they do six sets of 10 with two minutes rest. And there's athlete B that does six sets of 10 with three minutes rest. Athlete A will likely see the highest muscle gains because of the metabolic stimulus that they're driving with the shorter rest periods.

• 9:27Andrew D. Huberman?

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• 10:11Andrew D. Huberman?

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• 11:06Andrew D. Huberman?

  What about day-to-day recovery? I mean, the workout that you described is intense but short. How many days a week can the typical person do that and sustain progress?

• 11:16Speaker 01

  Yeah, I mean, I think that comes back to your training age and your training history. Obviously, there's a resilience and a robustness with an incremental training age. So a protocol like that, we would look at two times a week, something that's pretty intensive like that. Because again, it comes back to the point you make is that you really need to be, for want to better term, suffering a little bit through that type of protocol, both in terms of the challenge of the load, but also being able to tolerate the metabolic stress that you're exposed to. It's a bit of a sicko feeling, right? Because of the lactate that you're driving up. So I wouldn't promote as an athlete doing that type of modality multiple, multiple times unless you're from the realms of bodybuilding and then you're really, that's the sole purpose

• 12:00Speaker 01

  of what you're trying to achieve. If it's just somebody, a weekend warrior that wants to keep in shape and look good, I would say two times a week for a really challenging workout like that and then flex the other types of workouts within the week to have more of a volume emphasis where you reduce the intensity and you might just look at larger rep ranges from 12 to 15 to 20. Another workout where you're looking at reducing the volume but increasing the intensity and really trying to drive a different stimulus to give you more endpoints of success.

• 12:34Andrew D. Huberman?

  Last time I was here at the UFC Performance Institute, we had a brief conversation and I want to make sure I got the details right, that in the short term, a big increase in stress hormone can lead to an increase in testosterone, like a parachute jump.

• 12:48Speaker 01

  Correct.

• 12:49Andrew D. Huberman?

  But, so, stress can promote the release of testosterone.

• 12:54Speaker 01

  Yeah.

• 12:55Andrew D. Huberman?

  That was news to me.

• 12:56Speaker 01

  Right.

• 12:57Andrew D. Huberman?

  We always hear about stress suppressing testosterone, stress suppressing the immune system, all these terrible things, but in the short term, you're saying it can actually increase the release of testosterone. So I have that right?

• 13:09Speaker 01

  Correct.

• 13:09Andrew D. Huberman?

  Okay. And so then the second question is, does my cognitive interpretation of the stressor make a difference? In other words, if I voluntarily jump out of a plane with a parachute? Does it have a different effect on my testosterone than if you shove me out of the plane against my will, or presumably with a parachute?

• 13:29Speaker 01

  Right. I mean, so, so this was what all my PhD work was, was looking at was the, you know, the, the pre, the, the exposure to a stressor and the pre-arousal of how your body essentially prepares for that stressor and then how it manages it throughout the exposure to the stress. We used a resistance training protocol that, that these athletes knew was going to be very, very challenging. It's gonna be, there's gonna have some anxiety to doing it, they knew there were gonna be some physical distress from doing it. And therefore, you know, their, their mindset of how they were gonna approach that was already set. So what we saw prior, 15 minutes prior to the, the start of an exposure to, to the

• 14:11Speaker 01

  workout, the, the epinephrine, the noradrenaline, the adrenaline was already starting to prepare the body sympathetically and to go into what it knew was going to be a very, very challenging workout.

• 14:22Andrew D. Huberman?

  So what's, what was the takeaway there? Is, is the stress good for performance or is it harmful?

• 14:27Speaker 01

  That's a great question. From my data, certainly, the, the greater the arousal, the higher the performance was from a, from a physical exertion perspective. There's definitely a bio, an individual bio kinetics to some of these hormonal kind of releases. Inasmuch as those guys that had the highest, you know, adjuvant response in terms of epinephrine release, norepinephrine release, also sustained force output through, for a longer period of the workout than those that didn't. So the, the, the individuals that had a lower stimulus of, of the sympathetic arousal, let's say, certainly didn't perform as well throughout the workout.

• 15:05Andrew D. Huberman?

  There's another side to this that I want to ask about, which is the use of cold, in particular, things like ice baths, cold showers. In theory, that's stress also. It's epinephrine. And so. How should one think about the use of cold for recovery?

• 15:23Speaker 01

  You know, throwing your body into, you know, a cold tub, an ice bath, or whatever it may be, certainly is going to have a physiological stress response. Now, people are using that for different end goals. And again, I think that's where the narrative has to be explained. If you are using the stress specifically to manage the mindset, to use it as a specific stress stimulus, that's the same as me doing six by 10, 80%. You know, you're just trying to find something to disrupt the system, to do something that's very, if one had a better term, painful, discomfort, whatever. You're just finding a stressor and then being able to manage the mindset. But if you're using cold specifically from a physiological perspective

• 16:08Speaker 01

  to promote, you know, redistribution of vascular, you know, of blood flow, you know, to different vascular areas of muscle that you feel have gone through a workout, that are damaged, or whatever it may be. I think there's, we've got to understand what that stress mechanism is. And, you know, the data, the literature is certainly still out there with respect to cryotherapy and cold baths and some of these, you know, high, these cold exposures in terms of what they do at the level of the muscle tissue. If that's, if that's the target, if you're trying to promote a flushing mechanism, or you're trying to promote redistribution of the blood flow, what you've got to understand is that cold is going to clamp down every part of the vascular system.

• 16:52Speaker 01

  And we've really got to understand how the muscle would be redistributed to areas of interest. So, you know, I think the stress response is, is, is a real thing with respect to, you know, cold exposure. But I think the narrative around what are you using the cold for has to precede the conversation.

• 17:14Andrew D. Huberman?

  And cold, I've heard, can actually prevent some of the beneficial effects of training, that it can actually get in the way of muscle growth, et cetera.

• 17:25Speaker 01

  Yeah, there's some pretty robust data out there now showing that it definitely has an influence on performance variables like strength and power in particular, but absolutely in terms of muscle hypertrophy. And there's a big kind of theme in the world of athletic performance right now in terms of periodization of cold exposure as a recovery modality. When do you use cold? Should you be using cold for recovery in periods of high training load when you're actually pursuing, maybe general preparatory work, we're actually trying to pursue muscle growth? Well, that's usually where you get the most sore. It's usually where you feel the most fatigued. But it's probably not the most beneficial approach to use an ice bath in that scenario because you're dampening, you're

• 18:10Speaker 01

  dulling the mtor pathway and the hypertrophic signaling pathway. Whereas in a competition phase where actually quality of exercise and quality of execution of skill and technical work has to be maintained, you want to throw the kitchen sink of recovery capabilities and recovery interventions in that scenario because you now, the muscle building activity should be in the bank. That should have been done in the general preparatory work. And now you're focusing on technical execution. So you're absolutely right.

• 18:44Andrew D. Huberman?

  That's interesting. So if I understand correctly, if I want to maximize muscle growth or power or improvements and adaptations, then the inflammation response, the delayed onset, muscle soreness, all this stuff that's uncomfortable and that we hear is so terrible is actually the stimulus for adaptation. And so using cold in that situation might short circuit my progress. But if I'm, I don't know that I'll ever do this, but if I were to do an Ironman or something or run a marathon under those conditions, I'm basically coming to the race, so to speak, with all the power and strength I'm going to have. And so there, reducing inflammation is good because it's going to allow me to perform more work, essentially.

• 19:28Speaker 01

  Absolutely. Yeah. You have to be strategic about when you use some of these interventions. And the time when you're preparing for a competition is the appropriate time when you want to drive recovery and make sure that your body is optimized. When you're far away from a competition date or out of season or whatever it may be, and you're really trying to just... Tear up the body a little bit to allow it to its natural, you know, healing and adaptation processes to take place. Well, you don't want to negate that, you know, you want the body to optimize its internal recovery and that's how muscle growth is going to happen. So.

• 20:04Andrew D. Huberman?

  So interesting.

• 20:05Speaker 01

  There's a time kind of consideration that you need to make with these interventions for sure.

• 20:09Andrew D. Huberman?

  At the UFC Performance Center, are the fighters periodizing their cold exposure? Or are they just doing cold at will?

• 20:18Speaker 01

  Well, it's not just the UFC. And again, I talk about my personal experiences with different sports. I think just education around where science is at and our understanding of concepts like the use of cold exposure for recovery, ice bath, you know, everyone wants to jump in an ice bath. But I think as we've stepped back and scientists have started to say, have started to figure out and look at some of the data, you know, we're now more intuitive about, well, actually that might not be the best or the most optimal approach. And I think that's any given sport. So yes, certainly here at the UFC, we're trying to educate our athletes around, you know, appropriate timing. And it's the same with nutrition. It's the same with an ice bath intervention. It's the same with lifting weights. It's the same with going for a run or working out on the bike.

• 21:03Speaker 01

  You know, there's tactics to when you do things and when you don't do things. And I think, you know, stress and cold exposure, we have to have a consideration around that as well. But it's not just, you know, MMA fighters, that's any athlete. And I think it's the best, the best professionals, the most successful professionals do that really well. They listen, number one, they educate themselves and then they build structure. And I think, you know, at the most elite level, we always talk about it here at the UFC, but the most elite level, you're not necessarily training harder than anybody else. Everybody in the UFC trains hard, like everyone is training super hard. But the best athletes, the true elite levels are the

• 21:47Speaker 01

  ones that can do it again and again and again on a daily basis and sustain a technical output for skill development. Therefore, their skills can improve or physical development, their physical attributes can improve. So that ability to reproduce on a day to day basis falls into a recovery conversation. Now, when is the right time to use something like an ice bath? And when isn't is part of the high performance conversation for sure.

• 22:12Andrew D. Huberman?

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• 23:36Andrew D. Huberman?

  If you'd like to try Eight Sleep, go to eightsleep.com/huberman to get up to $350 off the new Pod 5. Eight Sleep ships to many countries worldwide, including Mexico and the UAE. Again, that's eightsleep.com/huberman to save up to $350. For somebody that wants to get better at sport, do you recommend a particularly long or short training session? Does intensity matter, or is it just reps?

• 24:04Speaker 01

  No, it's it's not a volume driven exercise, it's a quality driven exercise. It is about rehearsal of accurate movement, accurate movement mechanics. And the soon, as soon as that becomes impacted by fatigue or inaccurate movement, you're now losing the the the motor learning, you you're losing the accuracy of the skill that, you know, people can call it muscle memory or whatever they want, right? But essentially, you're grooving neural axons to to create movement patterns. And they're situational throughout sport, right? You know, whether it's a Cruyff turn in soccer or a jump shot in basketball or a forehand down the line. You you can carve out that particular posture and position and skill and you can isolate it.

• 24:47Speaker 01

  And you can drill it again and again and again. Now, as soon as fatigue is is influencing that repetition, it's time, it's time to stop. And the best coaches understand that. It's shorter sessions that are very high quality. And I think the best athletes, in my experience, are the ones that consciously and cognitively are aware of it at every moment of the training session. A a three hour session versus a ninety minute session. You know, we'll we'll take the ninety minute session any day when it comes to skill acquisition, because that's going to be driven by quality over quantity.

• 25:22Andrew D. Huberman?

  Yeah, training and skill learning is incredibly mentally fatiguing. You hit a really hard workout or run early in the day. What leads to the mental fatigue after physical performance?

• 25:34Speaker 01

  If you have an amazing coach who is setting up training in a particular way, it's challenging. There's a strain related to it, and I'm not talking physical strain. I'm talking figuring things out, you know, figuring out the skill. And I think that can be stressful, like, you know, if the if they hit the right technique, you know, that reward center in the brain, that dopamine shot is is gonna fly up there. And there's only so many times that we can get that before that becomes dampened. And I think there's an energetic piece to it, you know, there's the fueling of of the brain. There's the, there's the, the carbohydrate fueling exercise that actually the strategy around how you fuel for learning and fuel for physical training is is actually pretty similar.

• 26:15Andrew D. Huberman?

  Glucose.

• 26:15Speaker 01

  Yeah, it's it's glucose, it's sugar at the end of the day, right?

• 26:19Andrew D. Huberman?

  Do you think that?

• 26:21Andrew D. Huberman?

  Nutrition that doesn't include a lot of glucose, doesn't include a lot of carbohydrates is a problem.

• 26:28Speaker 01

  Yeah, again disclaimer, I'm not a dietitian. But I, I, I think it's, it comes down to metabolic efficiency. You know, we rarely advocate a high performance athlete in a, in a high intensity intermittent sport like MMA, being totally ketogenic. Because at the end of the day, some of those high intensity efforts usually require, you know, carbohydrate fueling for the high and the energy, the energy is produced at those high intensities.

• 26:56Andrew D. Huberman?

  Can I interrupt you real quick? What about ketones for people that are ingesting carbohydrates? This is an interesting area because people always hear ketones and they think, oh, I have to be ketogenic to benefit from taking ketones.

• 27:07Speaker 01

  Right.

• 27:08Andrew D. Huberman?

  But there are a number of athletes and recreational athletes now as well, taking liquid or powder based ketones on, even though they do eat rice and oatmeal and bread and other things. So are there any known benefits of ketones, even if one is not in a state of ketosis?

• 27:27Speaker 01

  The use of ketones that I'm primarily aware of is, is in our sport is after the event, you know, in terms of the brain health with, with athletes that take, you know, potentially taking trauma to the brain, et cetera, and looking to maintain the, the fueling and the energy supply to the brain. But yes, it's probably a little bit out of my remit, so I don't want to talk on that because I'm not, I'm not fully familiar with that. And to come back to the original question, if it's a, you know, general population, then yes, I think there's, there's a place to argue that actually being on a ketogenic diet at times, and maybe this is cycling exercise, maybe not, you know, I don't mean cycling a bike, I mean cycling ketosis is beneficial because I think it's going to lead to better metabolic management and metabolic efficiency.

• 28:10Speaker 01

  Those lower intensities where we should be fueling our, our metabolism with lipids and fats. Clearly the, the Western diet and, and you know, the modern day diet is heavily driven by processed food and carbohydrates that, you know, people become predisposed to utilization of that fuel source above lipid. Use fat use intensities that are very low. So you know, some of our data with the fighters shows that as well. But I think the challenge for us is that we're working with a clientele that require high intensity bouts of effort. So you know, fueling appropriately is very important for that. Now, we use, we use tactics here where we essentially have athletes on

• 28:53Speaker 01

  what you would say kind of is a largely a ketogenic diet, but then we will fuel carbohydrates around training sessions. So we'll do very timed exposure to carbohydrates. So it's

• 29:05Andrew D. Huberman?

  Post-training.

• 29:06Speaker 01

  Post-training, immediately pre, during, and then immediately post. And then the rest of their diets, you know, breakfast, lunch, and dinner are what would look like ketogenic type approaches. So we're trying to be very tactical in the exposure to maximize the intensity for the training and then return to a metabolically efficient diet, which is heavily reduced in carbohydrate because we've fueled the sessions that need

• 29:32Andrew D. Huberman?

  The way I understand metabolic efficiency is that you're, you teach the body to use fats by maybe doing long, long bouts of cardio, maybe lowering carbohydrates a bit. So teaching the body to tap into its fat stores for certain periods of training. And then you also teach the body to utilize carbohydrates by supplying carbohydrates immediately after training and before training. You teach the body to use ketones and then you use them at the appropriate time as opposed to just deciding that one of these fuel sources is good and all the others are bad or dispensable. Do I have that correct?

• 30:04Speaker 01

  Yes, you're absolutely right. I mean, at low intensities of exercise or just day-to-day living, we shouldn't be tapping into our carbohydrate fuel sources extensively. That's, that's for higher intensity work or, you know, the fight or flight needs of stress, you know. If, you know, athletes or any individual has a, you know, a high carbohydrate diet, they're going to start to become predisposed to utilizing that fuel source preferentially. Now, at low intensity, that can be problematic, certainly for an athlete, because if they Preferentially use carbohydrate at lower intensities. When the, when the exercise demand goes to a higher intensity, they've already exhausted their fuel stores.

• 30:48Speaker 01

  You know, they can't draw upon fat because the oxidization of that, that fat is just too slow. So they're essentially now become fatigued because they've, they've already utilized the carbohydrate stores. So what we try to do, yes, through diet manipulation and a little bit of exercise manipulation is, as you say, teach the body or train the body to preferentially use a specific fuel source, fat obviously at lower intensities and carbohydrate at high intensities. And we would look at specifically the crossover point between the two tells a lot in terms of how an athlete is, is ultimately, um, you know, how their metabolism is working.

• 31:20Andrew D. Huberman?

  I think most people are looking for that one pattern of eating, that one pattern of exercising that's going to be best for them or sustain them. And they often look back to the time when they felt so much better switching from one thing to the next, but the adaptation process itself is also key, right? Teaching the body. And I, um, so if we were to, um, just riff on this just a little bit further, if somebody is eating in a particular way and they want to try this kind of periodization of nutrition, um, could one say, okay, for a few weeks, I'm going to do more high intensity interval training and weight training and I'm going to eat a bit more carbohydrate because I'm depleting more glycogen. Then if I switch to a, a phase of my training where I'm doing some longer runs, maybe I'm

• 32:04Andrew D. Huberman?

  not, maybe I'm training less, maybe I'm just working at my desk a little bit more, then I might switch to a lower, lower carbohydrate diet. Do I have that right? And then if I'm going to enter a competition of some sort, certainly not UFC.

• 32:15Speaker 01

  Right.

• 32:16Andrew D. Huberman?

  Or MMA of any kind, to be clear. Uh, not because it isn't a wonderful sport, but because it's, that wouldn't be good for my other profession. But, um, if I were going to do that, then I would think about stacking carbohydrates, ketones and, and fats. Is that, do I have that more or less right?

• 32:32Speaker 01

  I mean, I think, yeah, you did said it eloquently. At the end of the day, you're consciously understanding what the, um, the exposure to, to physical exertion is, and you're flexing your diet accordingly.

• 32:45Andrew D. Huberman?

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• 33:29Andrew D. Huberman?

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• 34:14Andrew D. Huberman?

  A couple more questions. I can't help myself. I know we talked about temperature earlier. I have to ask you about heat. One of the reasons to deliberately expose oneself to heat is for things like growth hormone release, et cetera. We talk about this, but how does one get better at heat adaptation, or at least what are you doing with the fighters to get them better at dealing with heat, barring like hyperthermia and death? Like, I mean, obviously, you heat up the brain too much, people will have seizures and die, but you lose neurons. But what's the right way to acclimate heat?

• 34:44Speaker 01

  Yeah, so we we we normally start with about fifteen minutes of exposure. Now, if someone's really lacking acclimation to heat, you know, you can do that in three, five minute efforts. Do you know what I mean? And actually take

• 34:55Andrew D. Huberman?

  This is hot, hot sauna.

• 34:56Speaker 01

  Yeah, hot sauna. Take time to step out.

• 34:58Andrew D. Huberman?

  Two hundred degrees or something.

• 34:59Speaker 01

  Correct. Yeah, yeah, two hundred Fahrenheit. Yes. And we we we try to work up to thirty to forty minutes to forty five minutes in the sauna continuous. Now, we we have to understand, you know, what what's the advantage of heat acclimation for our athletes? Ultimately, their ability to sweat and to lose, you know, body fluids is going to be advantageous to their weight cut process, their ability to make weight. It is a technique that these guys, some of these guys adopt. So if you don't have, you know, high sweat rates, it means you're going to have to sit in the sauna for longer and longer and longer to get the same delta in sweat release. And so the more acclimated you are, the more your body is thermogenically adapted, the more

• 35:43Speaker 01

  sweat glands you have. So, you know, we start with fifteen minutes and then we just try to add on and add on across the time. And now, now for us, we kind of found about fourteen sauna exposures starts to really then drive the adaptations that we're looking for. So it's not a quick fix. You know, a heat acclimation strategy has to happen long before fight week or long before the fight. You know, this is a, this is a process that has to begin, you know, eight to ten weeks before the fight so that we can actually get that adaptation and that tolerance to the stressor, to the exposure of heat.

• 36:14Andrew D. Huberman?

  This is interesting. I, until today, when we talked about this earlier and again now, I didn't realize that, but it makes perfect sense now that I hear it, that heat adaptation is possible, that you're basically can train the body to become better at cooling itself, which is what what sweating is.

• 36:31Speaker 01

  The body is, you know, as an organism, as an organic system, it's hugely adaptable. It's hugely plastic. But I think the skill is understanding the whens, the whys and the wheres in terms of changing the overload, changing the stimulus to drive specific adaptation. And philosophically, that's, that's how we go about our work here. We talk about adaptation led programming. Now, adaptation led programming fits into every single category, not just lifting weights or running track. It fits into nutrition. It fits into sitting in the sauna. It fits into being in a cold bath or not. It fits into so many different things because we're driven by scientific insights. And that's how we really want to go about our business.

• 37:13Andrew D. Huberman?

  If someone wanted to experiment with heat adaptation, or experiment with cold adaptation, or change up their training regimen, or diet, and look at metabolic efficiency, do you think 12 weeks is a good period of time to really give something a thorough go and gain an understanding of how well or how poorly something works for oneself? Or would you say eight is enough, or three?

• 37:35Speaker 01

  For 99% of things that change within the body that physiologically adapts to a training stimulus, or an overload stimulus, you're going to start to see either regression or progression, beneficial or detrimental effects within three months, absolutely, I would say. And I think, you know, the individual interpretation is always, has to be considered. And I think that's where it comes back to be a thinking man's athlete, or be a thinking man's trainer, like someone that's going through exercise. You have to consciously understand where your body's at at any moment in time. You know, you've got to be real with yourself. You can create a journal, create a log of your training, create a log of your feelings, your subjective feedback of, you know, how you felt, your mood, your sleep.

• 38:18Andrew D. Huberman?

  Do your athletes do that?

• 38:19Speaker 01

  Yeah, yeah, we try to promote that, because again, that's part of this process, you know? It might be 12 weeks for you, but I might get the same responses in eight weeks, you know? We could put 15 guys on the mat and give them the same workout, and there's going to be 15 different responses to that same workout, because the human organism is so complex, and in nature, that it's going to adapt differently. You know, some people will tolerate it, some people are going to be challenged by it, some people have got a metabolic makeup that's going to promote it, some people are metabolically challenged by it. You know, there's just so many different things that we have to consider, and that's what we try to do here. It's the cross we bear, is that we try to understand on an individual level, how to

• 39:03Speaker 01

  optimize athletic performance.

• 39:05Andrew D. Huberman?

  Duncan, when you speak, I learn so much. I'm going to take the protocols that I've heard about today, I'm going to think about how I'm training, and how I could train differently and better, how I'm eating, how I could eat differently and better, for sake of performance, and just in general.

• 39:24Andrew D. Huberman?

  Thank you so much for your time, your scientific expertise, the stuff you're doing in the practical realm, it's immense. So hopefully we can do it again.

• 39:32Speaker 01

  Yes, thank you. This has been a blast. I appreciate it. And yeah, keep doing what you're doing because I know there's a lot of people out there that love the platform. So thanks for the invite. It's been awesome.

• 39:41Andrew D. Huberman?

  Thank you. Thanks so much.

• 39:42Speaker 01

  All right.

• 39:48Speaker 02

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