How to build muscle & stay strong at any age: The surprising links between your gut health, strength training and healthy ageing | Prof Claire Steves & Prof Tim Spector

How do you build muscle and stay strong as you age? For most of us, muscle loss starts in our 30s. It’s easy to think that you can combat this and stay strong into old age by strength training and eating plenty of protein. Exercise and macros matter, but scientists are uncovering another important piece of the puzzle - a direct connection between your gut health and healthy ageing. It could change how we think about staying strong as we get older. In today's episode, Professor Claire Steves - a world-leading expert in ageing and health - and Professor Tim Spector explore the gut-muscle axis - how your gut microbiome influences your muscle health. They explain why maximum protein doesn't mean maximum muscle, how gut bacteria ‘talk’ to muscle tissue, and why an unhealthy gut can make muscles resistant to growth. For listeners looking for simple ways to support their muscles today, this episode includes practical advice you can easily fit into your routine. Claire and Tim share quick daily habits and explain how to get your protein from diverse plant sources. Could changing what you feed your gut microbes today be the key to keeping your body strong for decades to come? 🌱 Try our science-backed and tasty wholefood supplement Daily30 🌿Let your gut microbes snack on the ZOE Gut Health Bar Build healthy habits. Download the ZOE app today and start your trial for just £2.30 for your first week. 👉 Join ZOE Follow ZOE on Instagram. Timecodes 00:00 Intro 04:08 Why muscle matters for healthy aging, not just the gym 06:37 The hidden organ: how your muscles talk to your body 10:35 Why it gets harder to keep muscle as you age 11:37 Can you have a 20-year-old's muscles at 70? 13:29 Can muscle loss increase your risk of cancer? 15:51 Why skinny doesn't mean healthy 17:40 What is sarcopenia? 20:52 How 4 days of bed rest can shrink your muscles 23:31 Gut-muscle axis: how gut bacteria talk to your muscles 23:53 Why protein stops working as you age 26:11 Can improving your gut health build stronger muscles? 28:57 Can strength training change your gut microbiome? 30:57 Can the Mediterranean diet make your legs stronger? 34:01 The diet trial that improved muscle and bones, no gym 34:55 Is there a magic gut bug for building muscle? 39:38 Intermittent fasting: should you exercise before breakfast? 44:43 Can too much protein weaken your muscles? 46:32 How much protein do you really need per day? 49:20 The best protein foods to feed your gut and muscles 52:26 Carnivore diet: what meat and shakes do to your gut 53:46 Strength training, cardio or balance: what do you need? 56:04 The easy 2-minute toothbrush habit for better muscle health 57:21 Key takeaways: muscles, microbes, and the protein myth26:11 Can improving your gut health build stronger muscles? 📚Books by our ZOE Scientists The Food For Life Cookbook Every Body Should Know This by Dr Federica Amati The Appetite Reset by Dr Federica Amati Food For Life by Prof. Tim Spector Ferment by Prof. Tim Spector Good Mood Food (preorder) by Prof. Tim Spector Free resources from ZOE The Smart Snacking Guide: How to feed your gut, fuel your day, and snack without guilt The Hormone Harmony Guide: Tuning Your Body’s Internal Orchestra Eating for Better Brain Health: Your brain-gut blueprint How to eat in 2026 - Discover ZOE’s 8 nutrition principles for long-term health Live Healthier: Top 10 Tips From ZOE Science & Nutrition Gut Guide - For a Healthier Microbiome in Weeks Better Breakfast Guide Mentioned in today's episode Master Cyclist Study, King’s College London (2018) Physical Activity and Reduced Cancer Risk, Nat Rev Cancer (2008) Bed Rest and Muscle Loss, Diabetes (2016) Microbiome Interventions and Inflammation, Cureus (2025) The Gut Microbiome and Muscle Strength, BMC Geriatr (2021) Resistance Training Reshapes the Gut Microbiome, Sports Med Open (2026) The Mediterranean Diet and Muscle Strength, Physiotherapy Theory and Practice (2025) Short-Chain Fatty Acids and Muscle Mass, J Cachexia Sarcopenia Muscle (2024) Mitochondrial Properties in Skeletal Muscle Fiber⁠, Cells (2023) Episode transcripts are available here.

• 0:02Speaker 00

  Welcome to Zoe Science and Nutrition, where world-leading scientists explain how their research can improve your health.

• 0:13Speaker 00

  Right now, in every muscle in your body, a demolition is underway. Old proteins have been torn down, brick by brick, and right alongside it, a rebuild. New proteins have been laid down just as fast. This constant invisible tug-of-war between breaking down and building up muscle fibres continues from the cradle to the grave. But this delicate balancing act doesn't keep working as it should forever. Once you pass the age of 30, the demolition crew starts to work faster than the builders, and most of us lose muscle mass. We all know that exercise can help build muscle. But today's guest has discovered something completely new in her research.

• 0:55Speaker 00

  It turns out that this demolition tug-of-war is influenced by something other than your decision to go to the gym. And that something is hiding in the dark, coiled 30-foot tube that is your gut. Or more accurately, it's one trillion things, your gut microbes. But how can they possibly influence the muscle fibres in your calf? The answer is that the microbes that inhabit your gut manufacture molecular messages that travel through your bloodstream and then directly in your muscle tissue, tipping that tug-of-war one way or the other. And when it tips the wrong way, the consequences are real. Our bones weaken, our risk of falls rises, and for some, it can even prove fatal.

• 1:40Speaker 00

  This is called the gut-muscle axis, and scientists are only now unraveling its complexities to understand how harnessing it might keep us strong now and into the future. To guide us through this amazing new research, I'm joined by Claire Steves, a professor of ageing and health at King's College London, who's at the forefront of research connecting the gut microbiome to muscle health and ageing. And alongside her is Professor Tim Spector, one of the world's leading microbiome scientists and my scientific co-founder at Zoe. Today, we're going to listen to the constant conversation between your gut and your muscles and uncover what advice it has for us, what to eat, how to train, and how to stay strong for the rest of your life.

• 2:25Speaker 00

  Claire, do we only start to lose muscle mass when we're old?

• 2:29Speaker 01

  No.

• 2:31Speaker 00

  If we lose muscle mass as we age, does it increase our risk of bone fractures?

• 2:36Speaker 01

  Yes.

• 2:38Speaker 00

  Is it true that a healthy gut microbiome helps to build healthy muscles?

• 2:43Speaker 01

  Possibly.

• 2:44Speaker 00

  Tim, can our gut bacteria communicate with our muscles?

• 2:49Speaker 02

  Yes.

• 2:50Speaker 00

  Claire, as we age, should we increase our protein intake?

• 2:55Speaker 01

  Yes, with some caveats.

• 2:58Speaker 00

  Can exercise on its own change the makeup of our gut microbiome?

• 3:03Speaker 01

  Probably not on its own, but we do know that people who exercise, when they exercise, their gut microbiome changes.

• 3:12Speaker 00

  And finally, Claire, what's the most common myth that you hear about muscle health and strength?

• 3:18Speaker 01

  I think it is maximum protein equals maximum muscle health.

• 3:22Speaker 00

  And it's not true?

• 3:23Speaker 01

  It's not true.

• 3:25Speaker 00

  One of my favourite things about doing this podcast is learning brand-new science direct from the researchers who are actually doing the studying and research that just totally changes the way that I think about the world. And I think that this episode is going to be one of those times. Listening to those answers, I find it a bit crazy to think that my muscles and my gut microbiome are linked, and even crazier to think that my gut microbes might actually be helping me to grow my muscles. If you thought that building muscles as you age comes down to lifting weights and eating more protein, you're about to find out that's only half the story. When I think about muscle building, I think of my son, who's 18, going to the gym and proudly showing me his biceps.

• 4:07Speaker 00

  So if you're listening to this and you're not an athlete, you're not 18 years old, you're not hoping to look great without your top on, why should you even care about your muscles?

• 4:17Speaker 01

  Well, you really should care about your muscles because actually, muscles are what's important for everything we do. Because even to get up out of the chair right now, I'd need to use my quads, and that gets difficult as we get older, actually. And so we can do a lot earlier in life to make sure we maintain our muscle function. But also, our muscles can do good things for the rest of our body as well. It kind of influences how our brain works, influences all manner of different other organs in the body as well.

• 4:43Speaker 02

  So soaks up things like blood sugar and can help prevent diabetes. So lots of things you don't necessarily associate with muscles do have a role.

• 4:53Speaker 00

  I think people listening to this, like, immediately understand that you need muscles to get out of a chair. That makes sense, and that obviously becomes really important as you get older. But the idea that my muscles are having an impact on my brain or any other part of my body, that seems wild and I don't understand it at all.

• 5:08Speaker 01

  Well, it does seem a bit weird, but I think the other thing that we haven't talked about yet is our muscles really do impact our inflammatory system or physical fitness. Physical exercise really impacts how our immune system works. And that is probably something to do with the cross-talk with the microbiome. But we know as well that people who have better physical function, better leg strength, for example, they have better cognitive ageing, they have reduced risk of Alzheimer's, as you say, reduced risk of diabetes and so on. So there's a whole cross-talk between the metabolism, the brain, the immune system, and the muscles.

• 5:42Speaker 02

  Yeah, I thought it was really strange that grip strength is one of the best predictors of your cognitive change as you get older. And you think, what's that got to do with it? So it's really understanding that all these different organs in our body, which we've thought just had one role, actually all part of this big organisation that keeps us healthy.

• 6:03Speaker 00

  I've got this model in my head of muscles are just something that sort of contract and they pull things closed and open. I understand how that's related to your fitness, and I can sort of understand that being fitter is good for me in general. But I want to come back to that question at the beginning about chemicals being released by the muscles, and you said yes. My simple model of they're just like a spring that, you know, pulls shut is clearly too simplistic?

• 6:29Speaker 01

  Well, that's really interesting. So yes, it is too simplistic because I think obviously muscle is a metabolic organ, so it is producing chemokines, myokines, it's influencing the immune system. But I think also it's simple because you've forgotten about the neuromuscular junction. So the muscle isn't just the muscle fibres, right? It's the muscle fibres and how they work together in teams called neuromuscular bundles. And how the nerves then, like, recruit and activate those muscles is really important for how the muscle actually functions. And then also, the way that the muscle functions is dependent on other cells inside the muscle, which kind of contribute to the health of those myofibres. So it's actually a kind of system, it's not just single, single sorts of cells that

• 7:14Speaker 01

  are working together in the muscle.

• 7:15Speaker 02

  And Claire, some people get fat deposits in the muscle. How does that change?

• 7:19Speaker 01

  Yeah, so that, that's really important. So fat in the muscle, but also fibre, fibrous tissue in the muscle. And remember that the muscles at the end, there's a lot of tendons in the ends of the muscles, which in young people like your son are really stringy and great. As we get older, they get much stiffer, and that affects muscle function as well. But you were just talking about muscle fat, so as we get older, we might, if we're lucky, maintain muscle sort of volume on a scan. But when you look clearly, you know, in more detail, you can see that it's infiltrated with lots of fat, and that's not good for the muscle and it's not good for the body as well.

• 7:56Speaker 00

  And that brings me on to wanting to ask about how muscle is maintained? Because I think we've all sort of got this idea now that you're supposed to go and do some exercise, you sort of strain it, and somehow this is good. But could you help us to understand what's actually going on in these muscles? I'll never forget the moment that everything shifted for me. I was at a public talk on nutrition, listening to a speaker explain that my gut had trillions of microbes in it and that these bugs shaped every aspect of my health. That speaker was Professor Tim Spector, one of the world's top 100 scientists, who became my co-founder here at Zoe. Nine years later, Zoe runs the world's largest gut health research study, and the conclusion is simple: gut health is health.

• 8:41Speaker 00

  How you feel, your long-term health and your digestion are all shaped by the state of your gut. As a listener to this show, you know how important it is to feed your good gut bugs. But I suspect that like me, you have a busy schedule, and often you feel you haven't given them all the different plants they crave. And that's exactly why we created Daily 30. It's a gut health supplement packed with over 30 plants that you sprinkle onto any meal. It tastes great, adds a satisfying crunch, and gives your gut the diversity it craves. Finally, a healthy habit that's easy to stick to. I should know, I take it every day. And because we're Zoe, we don't just guess, we test. We put our original Daily 30 formula through a randomised controlled trial, the gold standard of testing.

• 9:26Speaker 00

  The results blew us away and proved it supports your digestion, energy, and gut health. That trial helped us develop the formula we have today. Today, Daily 30 is a non-negotiable daily habit for me. So don't put your health off for the future. Go to Zoe.com/Daily30 and try it today.

• 9:44Speaker 01

  So I think what you're asking is about the balance, basically, in muscles. Yeah, so we often talk about catabolism and anabolism in muscles. Yeah, so people who are sort of on anabolic steroids, for example, yeah, there are things that build muscle. Anabolism means building muscle. Catabolism, especially if you're maybe unwell, under starvation, maybe have cancer or something like that. We can see catabolic things happening where the muscle is broken down quite rapidly. It's when basically the rest of the body is trying to use that muscle for nutrients to feed the brain and the heart and so on. So there's this constant balance in muscles as well as in bones, where you've got growth, repair and turnover happening. And that's what's changing as we get older, really, and also changing as we do exercise.

• 10:30Speaker 00

  And so does that only happen if I have cancer or I get really sick, this breaking down, this catabolism you're talking about?

• 10:37Speaker 01

  No, so it's happening all the time. There's a dynamic balance happening all the time and it's basically shifting the balance one way or the other. But yeah, certain conditions like starvation conditions or conditions like cancer can really, really shift the balance. It's basically telling the muscle to release all of that energy that's got stored.

• 10:52Speaker 00

  We were talking about my son's biceps.

• 10:54Speaker 01

  Yeah.

• 10:54Speaker 00

  It sounds like this process is going on every day. Could you just paint me a picture of it?

• 10:57Speaker 01

  Yeah, so as he does the exercises, he's going to be straining that muscle. Okay, and then there's going to be a period of time when that strain of that muscle is actually, it's going to be using the muscle. But it also might actually break down a little bit of the muscle in the process of doing it, especially if he's doing really high resistance training exercise. But then that gives a stimulus to the muscle to then repair and grow more. So even though he has, he might have an immediate sort of slight catabolism, then it's going to create signals that's then going to grow his muscle. And because he's a young man and he has testosterone on board, that's going to be quite an effective process that happens in him. So he can get much greater muscle growth as a man than say, for example, if you had a daughter, probably.

• 11:39Speaker 01

  And then also, he's probably, you know, guzzling protein like many of these young people are. And that does help build muscle as well. There's no doubt about that. That's an anabolic thing, but only to a certain length, to a certain extent, and only in certain contexts, which I think we'll go on to later.

• 11:56Speaker 02

  So someone older like myself, if I'm not exercising, generally I will be slowly losing that muscle because I won't be stimulating enough, whereas when you're young, you know, I look at pictures of when I was young, I didn't do much exercise, but I looked really fit. I have all these muscles and I don't remember doing any exercise, I look great. And now, you know, you've got to really struggle to not lose it. What's, what?

• 12:23Speaker 01

  Yeah, yeah, yeah, but partly, I mean, that's super interesting, isn't it? Young people, they just move around a lot. They've driven to move. We have a little bit less urge to move as we get older, which then unfortunately leads us to this kind of vicious cycle of not doing enough exercise, not doing enough stimulus to the muscle, and then the muscle's kind of going to break down. And so you see a massive difference between the sizes of an average man at the age of twenties muscle and the average man at the age of seventy, you know, really massive differences in muscle bulk. And also muscle quality because the fat's infiltrated into the older muscle.

• 12:57Speaker 02

  It's very depressing.

• 12:58Speaker 01

  It doesn't have to be like that. So I just described what is usual between sort of different age groups. But actually, we know from the master cyclist study within King's College London, which is a really great study, look it up, that actually if you really exercise your muscles, even if you're seventy or eighty, you can actually get good muscles like a twenty year old. And, you know, they may not be quite as strong muscles as a twenty year old, but certainly if you look on an MRI study, they can be as good, looking as good. So it isn't a completely depressing story. It just means that we just need to do more as we get older and not forget that moving is good.

• 13:35Speaker 00

  Well, that is very uplifting and I definitely want to spend the second half of this show really talking about what you can do. I'm already understanding like the muscle is much more complicated than I thought. It's doing many more things than I thought. Could we talk for a minute about what happens if that balance has broken down? You know, we end up in this place where your muscles are therefore shrinking year after year. What happens?

• 13:59Speaker 01

  Well, so unfortunately you're able to do less, therefore you do less. It's not a great outcome.

• 14:04Speaker 02

  Why is that a problem, doing less? Most people just say, oh, it's fine, I just sit on the telly and, you know, have a nice, comfortable life.

• 14:11Speaker 01

  Well, at some point you might need to get up off that sofa, go make a cup of tea. And ultimately, if your muscles and bones aren't very good, you can fall over and then end up in hospital. It's not, it's not a very good outcome. So I think, you know, definitely the end result of this sedentary lifestyle is not very good for our muscles and our bodies, as it were, moving. But it's also really not good for our brains, as we alluded to before. We still need to be able to move around in order to do things, including be social, get about, get food, get, get things like that, even if you're going to have a delivery to the door, whatever. Ultimately, moving, keeping healthy, keeping muscle function well is going to be important for whole body function.

• 14:50Speaker 02

  I think it's even wider than that. I think because muscles are involved in the immune system, the immune system is key to aging.

• 14:57Speaker 01

  Yeah.

• 14:57Speaker 02

  You're probably going to age faster and you're more likely to get things like cancer. So this is probably why there's this epidemiological association between sedentary living.

• 15:09Speaker 01

  Yeah.

• 15:09Speaker 02

  And later increases in things like heart disease, cancer, you know, the major killers and type two diabetes and of course obesity.

• 15:18Speaker 00

  This is all really obviously bad for you. I get the not being able to get out of the sofa, but how on earth do you end up getting cancer or diabetes or any of the rest of these things because of my muscles shrinking?

• 15:31Speaker 01

  Well, it's not just the muscles shrinking, it's all of those stimulus that go onto the body which are helpful. But say, say let's take the immune system, really good point, because our immune system is on the lookout for cancer cells, which could develop at any time in any of us, right? This is slightly more likely to happen as we get older because we have to have a certain number of knocks on our genome to get a cancer. But our immune system cells are actually doing a surveillance all the time and keeping most of those cancers, they're just killing them straight off. And if you have an immune system that's not working very well, then that doesn't happen and that's when cancers can grow. So we know that there's a very strong relationship between obesity and cancer. And we also know there's a strong relationship between physical inactivity and cancer.

• 16:16Speaker 01

  We know from epidemiological studies certainly that if we increase physical activity, we reduce the risk of cancer.

• 16:22Speaker 02

  Yeah, so a lot of this is due to this immune function of the muscles that are interacting with all the other immune signals. And yes, they'll have the surveillance, say anti-cancer, but they'll also be sending signals to the brain. If you've got lots of muscle, dampens down inflammation in the brain and is probably why there's also an association with mental health problems. So it has a really widespread effect. It's not the only thing, but it has this constant general factor that influences so many things in our body as we age.

• 16:55Speaker 00

  That's really fascinating. You mentioned about obesity being bad for your health and I think sort of everybody is aware of that. But what I'm struck by is you're talking about sort of these muscles and your muscle health has been different. So let's say that I'm just an average weight, I'm not overweight. Does it still matter to me whether or not I have healthy muscles? Or is it only because of it's sort of the link here between, you know, not ending up living with obesity?

• 17:21Speaker 01

  Yeah, I think actually what's really interesting with physical activity or muscle function is that you can see a relationship all the way along the spectrum. So you can see even going from very, you know, minimal levels of muscle function to just a little bit better. You can see beneficial effects on, say for example, you know, cognition outcomes or immune outcomes. But you can also still see them in those master cyclists and things like that. So it's, it's, it's quite a strong relationship that's working all the way across the spectrum. I think there is a point where you get to sort of super athletes who are really, really pounding their body really hard. And I think that's, you know, probably over and above what's needed. But ultimately, you know, me, definitely, I'm normal body weight. I definitely need to be looking after my muscles.

• 18:05Speaker 01

  I'm probably not doing enough, even though I am trying.

• 18:09Speaker 02

  Yeah, no, I think that's right. And I think it comes back to this myth that we still think about is that exercise is the number one way to lose weight, right? And we know that, we know that's not true. It has some effect in keeping your weight off if you've, you know, you're on a really good diet, but diet is so much more important. So we mustn't confound those two factors. And I think what we're seeing is that, yeah, muscle is a very independent factor to just putting on, on fat on its own. And, and that's why these studies, when they look at, you know, overweight people who exercise,

• 18:48Speaker 02

  they, you can offset quite a lot of the problems of the obesity with exercise. So we need to be thinking about muscles, not just about our weight. I think that's, that's the, that's the key message here.

• 19:02Speaker 00

  I'd like to talk next about sarcopenia. Could you help me to understand what that is and why we need to care about it?

• 19:11Speaker 01

  Certainly I can. People have known about sarcopenia for hundreds of years. Shakespeare described sarcopenia. If anyone knows the all the world's a stage speech, when he starts talking about older people, he says something about basically calf thickness. He says shrunk shank, I think that is.

• 19:27Speaker 02

  Runk and shanks.

• 19:28Speaker 01

  Yeah, exactly. He's making the first sort of like reference of what sarcopenia is. It's basically you've got small muscles. We now agree that sarcopenia isn't just about muscle bulk, okay? This is really important. It's also about muscle function, strength. So when we diagnose sarcopenia, we always look at muscles mass, as it were, and also muscle function. Because of course you could have a big muscle, but it's infiltrated with a lot of fat and it doesn't work very well. So sarcopenia is a combination of like the muscle bulk and the muscle function. And there's cut points where you say you're below a certain level and that means that you're sarcopenic, which means loss of muscle.

• 20:09Speaker 02

  The way to think about it, a lot of people know about osteoporosis. It's a sort of similar idea that you're losing bone and bone mass. And there's a certain point where you start to get at risk of fractures and things like this. So sarcopenia is the same thing for muscles and there's a range. There isn't one point at which it happens, but your risk of everything just gets more as you get less muscle. And it varies at different ages, just like those bone measures osteoporosis. So I think in the future, we will have, like we have bone density scans, we have sarcopenia scans or sarcoporosis scans, I'm not sure what they're called.

• 20:48Speaker 01

  Yeah, yeah. Well, indeed, like the DEXA scans, the very scan that we use for looking at osteoporosis. You can look at muscle bulk, but what's interesting about that is that that's not enough to get a diagnosis of sarcopenia because of this thing. Actually, some people have quite thin muscles, but they're really well functioning muscles, right? And they can do a lot with them. In fact, I'm one of those people. If you look at me in terms of my muscle size, it's actually quite small. I almost look like I'm on the threshold of sarcopenic. But I'm actually quite strong because my muscles are working well together and functioning well as a unit. And that's the other thing in sarcopenia that we really measure.

• 21:25Speaker 00

  And so is sarcopenia meaning my muscles are below some like absolute level? Or is it about the fact that my muscles sort of year after year are shrinking?

• 21:35Speaker 01

  No, it's the level actually. In medical sort of like world, we often dichotomize things because we want to know whether we're going to treat something or we're not going to treat something. And so we make a threshold, but ultimately we know that that threshold occurs because of gradual changes. So at some point, someone will go across that threshold.

• 21:55Speaker 00

  So if someone has sarcopenia, then it means that their muscles have fallen below some level at which it's now like a risk to their health?

• 22:02Speaker 01

  Exactly. And we really need to treat it. And we are working hard to work out ways to treat it. And we know that muscles, even once they become sarcopenic, can be improved.

• 22:13Speaker 00

  And so it sounds like you're saying this doesn't happen sort of overnight. It's not sort of like I go from having a really good level of muscles and just in a year I sort of go to having this.

• 22:23Speaker 01

  Oh, well, that's really, really interesting. And actually, it can happen almost overnight. In fact, it's not overnight, it's about four days. If you have four days of complete bed rest, studies have shown you can absolutely massively, I can't remember the amount, but it's really shockingly reduced.

• 22:41Speaker 00

  Four days?

• 22:41Speaker 01

  Yeah, four days. If we go into hospital, for example, and we're on ITU, we're completely paralyzed, say for a week, our muscles will massively reduce. And that's a real issue for when we want to then recover.

• 22:54Speaker 00

  So let's assume that I'm not in hospital, I haven't had to have bed rest. Is sarcopenia something normally that only much older adults need to worry about? You know, is this something that I start to worry about in my 60s, 70s, 80s?

• 23:09Speaker 01

  It's pretty unusual for somebody who is really young to get sarcopenia. People say sort of 40, you know, is when muscle bulk starts to, but I think it probably happens.

• 23:20Speaker 02

  I think it's in the 30s, isn't it? It's a bit like, but your bones peak at about 30 and your muscles probably similarly.

• 23:25Speaker 01

  Yeah.

• 23:26Speaker 02

  And then I've seen some data showing you lose 2% to 5% of your muscle every decade.

• 23:32Speaker 01

  Yeah.

• 23:33Speaker 02

  So it's why it's important, you know, both in your 20s and 30s to build up as much as you can.

• 23:39Speaker 01

  Yeah.

• 23:39Speaker 02

  And then try and reduce the amount you're losing it.

• 23:43Speaker 00

  So that's quite scary. It reminds me of some of the podcasts we've had talking about dementia and the fact that these risks start, you know, all the way back into your 20s, but it's sort of invisible or heart disease similarly like. And so now you're saying it's the same sort of with my muscles. Who's most at risk? Does everybody lose 2% to 5% the same or?

• 24:02Speaker 01

  No, so I think there's several differences. I mean, first of all, it's about what diet you have. Some people still have really too little protein to keep muscle function. So that's one thing. The second thing is around sort of physical exercise and putting that physical stress on. The third thing is probably about, you know, sex, actually. You know, women are much more at risk of sarcopenia than men because they don't have the helpful testosterone on board to build muscle. And then like diseases, so we've already sort of talked about the muscle effect on diseases, but there's also disease effects on muscles. So the key ones that are really like obvious and big are chronic bronchitis, which might be because of smoking, but it also seems to be that is a muscle condition, actually. And the second one is diabetes.

• 24:47Speaker 01

  So people with diabetes find it much more difficult actually to build muscle.

• 24:52Speaker 00

  So I'd like now to come on to like your really exciting research, Claire, about the links between gut microbes and muscles and how that might help me stay strong. Because if I thought the links between muscles and my brain seemed wild, like the idea that there is, I am told, a gut muscle axis. Like, how can muscles possibly be linked to gut health?

• 25:15Speaker 01

  Yeah, well, that's a really good question. I think one of the things we need to unpick here is this idea of anabolic resistance. And I think that's really key. We talked earlier about anabolism, building up muscles, yeah? So that anabolic steroids or like testosterone helps you build things, right? And catabolism being the other way around. So anabolic resistance means you're giving protein, for example, to say somebody, an older adult or somebody with diabetes or obesity or somebody with a poor gut microbiome. And it doesn't make any difference to their muscles. They don't put on muscle bulk, they don't increase muscle function. And that's kind of curious. Why is that the case? And actually, in older adults, this came apparent sort of about 10, 15 years ago.

• 26:00Speaker 01

  People would give the same amount of branched chain amino acids, leucine, for example, to young people and they would see an increase in their muscle bulk. And they did the same to older people and they didn't see. They needed more protein to get the same benefit in older people than younger people. And that's when this kind of like concept of anabolic resistance came in. So then we started to think, well, how does anabolic resistance happen? And we've got a number of different mechanisms that we think might be key. And funnily enough, many of them kind of come down to the gut microbiome. So things like inflammation. So we know that one of the key things that is really important about gut microbiome

• 26:44Speaker 01

  is its interaction with the white cells in the gut, training the immune system, reducing inflammation, maybe also some evidence of a good microbiome protecting against, if you believe it, leaky gut. So the leakage of microbial compounds into the blood, which then causes a storm of inflammation. So a gut microbiome can help inflammation, also can help metabolism, insulin resistance, which then also helps those muscle cells take on that protein. So there's a whole web of things that relate the gut microbiome to muscle function

• 27:25Speaker 01

  and seem to be explaining why some muscles resist anabolism.

• 27:32Speaker 00

  Do we now understand specifically anything about what our microbiome is doing that leads to that improvement in muscles? And you sounded like you were saying inflammation was maybe an important part of that, if I understood right?

• 27:42Speaker 01

  So I think inflammation is definitely an important part of that. And we know that from studies where we've done direct microbiome interventions and seen changes in inflammation. And we also know that from studies where we know that changes in inflammation relate to muscle function. We don't have that many studies showing a very clear link with between a microbiome intervention and muscle function. We tried to do that actually with a trial within twins. And we, in 12 weeks, we didn't get a clear effect on muscle function, although everybody got better. So it was difficult to tell the difference between the intervention and the control. But there are some other studies that do show that.

• 28:25Speaker 01

  And there's some really interesting new work showing that it may not be just about inflammation. It may also be about other functions actually within the muscle cells that are really key. There's some early work showing that mitochondria, which are the sort of like energy powerhouses of cells, which are really important in muscles, seem to be affected by changes in the gut microbiome. So that's a really interesting angle.

• 28:50Speaker 00

  Do you know someone who's always exercising but isn't getting all the benefits they want? Send them this episode right now. Better gut health might be exactly the answer that they're looking for.

• 29:02Speaker 00

  And my team said I should definitely ask you about short chain fatty acids.

• 29:08Speaker 01

  Yeah, so short chain fatty acids are metabolites that are produced in the gut by the gut microbiome, in particular by friendly bugs that digest complex carbohydrates principally and produce short chain fatty acids. Now, short chain fatty acids have several major roles. Firstly, they are things that other microbes that are also beneficial really like. So the bugs that create those short chain fatty acids help to foster a very diverse microbiome. The second thing is, is that short chain fatty acids are a key nutrient that the enterocytes, so the barrier cells within the gut, use for their energy stores.

• 29:51Speaker 01

  Yeah. And the third thing is that short chain fatty acids have direct effect on the immune system within those pairs patches, the white cells that circulate around the gut. And then can have roles further on, further abroad, in the, in the brain and in the muscles as well. So short chain fatty acids are a pretty key. And we know that they can be changed by having a good gut microbiome.

• 30:14Speaker 00

  And is there a link between them and then the muscle health that you were talking about earlier?

• 30:18Speaker 01

  Yeah, so I think there is. I must say that I have not been able to, like, in, within my experiments, sort of like deeply look at that. But others have shown links between short chain fatty acids and muscle function.

• 30:30Speaker 02

  Yeah, I'm sure there's, there's more than one mechanism, isn't there? I mean, there have been some clinical trials where they've done resistance training. Uh, so, you know, weightlifting for people who weren't doing it before, for middle aged people. And I think it was a German study about a hundred and fifty people where they did a couple of months of, of doing this and looked at their changes in their gut microbiome. And they didn't see massive shifts, but what they did see very clearly was big increase in the anti-inflammatory gut microbes. So these things like Fecalbacterium prausnitzii and Rosyburria.

• 31:04Speaker 01

  Yeah.

• 31:05Speaker 02

  That come up time and time again. And that means that the gut is actually helping the immune system and sending out chemical signals to the muscle to say, actually, calm down, you know, let's reduce the inflammation. And so it can presumably, uh, work more efficiently and get over this anabolic resistance. And that's probably one mechanism why it works, which is, is interesting because it, this is people who weren't doing cardio, so they weren't doing anything else, they were just doing weight training. And, and I think that's suggesting that certainly inflammation is one major thing. But we know that they're all related. So your short chain fatty acids, there's also branched chain amino acids.

• 31:48Speaker 02

  These little mini proteins, I guess you sort of described that, that are part of this whole protein process. And they can be converted into lots of different things by other gut microbes. And it looks like the state of your gut microbiome is, will determine how well you can use this stuff that comes in through your diet, convert them into these branched chains and either produce them as fatty acids, uh, or as, as carrying on to make, build proteins. And we don't really understand the whole story yet, but it seems like it's a complex picture. But undoubtedly, the gut microbes play a very big role in all the signals that your muscles are getting to either make muscle or to lose it.

• 32:28Speaker 01

  Yeah, that's right.

• 32:29Speaker 00

  Does this mean that supporting my gut health and particularly like, you know, my gut microbes can support my muscle health as well?

• 32:37Speaker 01

  Yes, I think that's, that's really clear. And this comes to sort of like really basic studies where we've looked at, for example, the diet that people have and then their muscle function. Yeah. And we can see that actually having really healthy diets, like having good Mediterranean diet, for example, can influence, uh, muscle function. We showed that with a study looking at leg strength, leg power. And it's a pretty clear relationship. It's not completely explained by inflammation. So there may be other factors like short chain fatty acids that are working.

• 33:10Speaker 00

  Could you tell me a bit more about that study? It sounds fascinating. So you're saying you actually looked at the impact of diet on people's strength?

• 33:19Speaker 01

  Yeah.

• 33:20Speaker 00

  Not taking them to the gym, which seems like the obvious thing, but actually like feeding them different food.

• 33:24Speaker 01

  There was a study within the twins cohort, which Tim and I work with. And, um, we looked at the relationship between Mediterranean diet score and leg explosive power, which is a really good measure of, for function of your, of your biggest muscles in your body, your thighs, basically, uh, where you get somebody to do an emergency stop, uh, with a power rig and really look at the how, how much power they can exert really quickly. And we saw a really strong relationship between a really Mediterranean diet pattern, higher score on that, much better leg explosive power. It was a really big study and certainly, you know, probably the first really big study to show that. And we tried to look to see whether that was all explained by inflammation using high sensitivity CRP,

• 34:09Speaker 01

  which is one of the measures we use to look at that. And we didn't see that explained all of it. So we don't know from that study what exactly explains this relationship, but it's clearly there. Interestingly, when we've looked at gut microbiome, we haven't seen a very clear relationship. And I think it's really interesting, the study you talk about, which I, I think it's a great study where, um, yeah, because that shows that the gut microbiome changed in response to resistance training. But I'm not totally sure that that's because, uh, like a direct effect of like the muscles. I think that might be an effect of the muscles reducing inflammation. So we know that resistance training reduces inflammation.

• 34:50Speaker 01

  So then, then if we actually have reduced inflammation, actually our gut microbes really like that. There's this really like nice cycle whereby muscle function means that actually our microbes are healthier. Therefore, our microbes can help our muscles and so on, so forth.

• 35:08Speaker 00

  Coming back to this study that you were describing between Mediterranean diet and strength. You're saying that the people who are eating much closer to this healthy Mediterranean diet actually had a lot more leg explosive power, which I love as a term.

• 35:23Speaker 01

  Yeah.

• 35:23Speaker 00

  And you're interpreting from that, that the diet was improving their, their gut health. And that was then leading to this improvement across their health overall and therefore actually improving their muscles?

• 35:34Speaker 01

  Yeah. So that's a really good point because we can't really, from that sort of study, really say that it, it's the diet that's improving the physical function because that's an observational study. So to be able to prove that kind of thing, you have to do intervention studies. And there was a really amazing effort, uh, study on Mediterranean diet called the New Age Study, which, uh, was done a few years ago where countries, I think it was five different European countries that all took part in this, including the UK. They did it for a year, Mediterranean diet. And they saw that people who were, took on their Mediterranean diet more, had better muscle function and better bone health, fun enough. We saw that within that intervention study.

• 36:14Speaker 00

  So in that study where they changed diet, the people who changed their diet more.

• 36:19Speaker 01

  Yeah.

• 36:19Speaker 00

  Improved their muscles and in fact improved their bones as well.

• 36:24Speaker 01

  They weren't sent to the gym. The only thing that changed with them was the diet.

• 36:28Speaker 00

  That's extraordinary. Do we think there's like a particular species of microbe in our guts as like a specialist in growing my muscles? And so it's like feeding this one particular sort of magic muscle bug that I need to, to do? Is that what's going on here?

• 36:47Speaker 01

  I think that the microbiome is a community job. Okay. It's not about single bugs. It's about, um, communities, an ecosystem that's working well together. And I don't think it's likely to, to sort of like pinpoint a single species. Um, and I think there's also a lot of overlap in the microbiome. So you might find that the sort of, that all the different functions are needed, but doesn't matter who does the job. Uh, do you agree, Tim?

• 37:15Speaker 02

  I see the microbiome really as an organ that signals to the rest of the body when all the omens are good, you know, there's like everything out there is pointing in the right direction. You can now grow and be healthy and produce more. Or it sends signals of famine and, you know, impending doom. And it says lockdown and get rid of your muscles, send, send everything to your heart and your brain to protect it. And I think this is what is going on in these scenarios. So that's what we want is a nice calm gut that's sending all the right messages to the rest of the body, saying, yeah, to your heart, to your muscles, be healthy, you can, it's a good time to grow.

• 37:55Speaker 02

  You know, harvest is good, uh, get on with it. That's my, that's my sort of current view of the gut.

• 38:01Speaker 00

  You're saying the microbiome, because it's seen all the food, is sort of saying, hey, everything is really good. We're getting all of this great nutrients we need. And so it's sending signals to the rest of the body saying like, keep your inflammation low, you know, grow, everything's good. Or alternatives like, wow, all I'm seeing is McDonald's, this stuff is terrible, you know, lockdown and, uh, you know, protect yourself because like, I don't know what's going on outside there in the world, but somehow we're missing all this stuff that we'd really like to be getting.

• 38:29Speaker 02

  Yeah, that's right. And it also is reflecting not just the diet, but also other diseases and things that are happening because it's picking up other signals. It's, you know, it's a two-way process, but a lot of it is coming from the diet, the outside world, what it's seeing.

• 38:45Speaker 00

  God, it's not only the outside like food, the microbiome is also responding to like the signals inside your body.

• 38:50Speaker 02

  Because we, you know, most of our immune system is around our gut. So in the same way, you, you're feeding, the outside world is through the, through the, the gut and the, and the diet and pollution and everything else. But things happening inside the body, whether you have allergies, immune diseases, whatever, uh, are coming from the immune system. Or, you know, presumably if, if you have four days of bed rest, that sends signals to your gut, to upset your gut through the immune system. So it's a two-way process, but it's, it's all about signaling, I think, to the other organs in the body. You know, green light, amber light, red light. And, uh, when things are bad, it's definitely a red light and that's often caused by bad meals.

• 39:36Speaker 00

  Claire, you mentioned, I think, earlier that there is messaging somehow coming from the muscles to my microbiome. It's not only the other way around. Do we know anything? Like, how can that even happen?

• 39:47Speaker 01

  The easiest way, I think, is to think about it as muscle function affects the immune system through myokines and cytokines that muscle releases, actually. Muscle releases a whole range of different sort of small chemicals that affect the rest of the body's systems.

• 40:03Speaker 02

  And they would get into the immune system and that's how they're connected with the gut, isn't it?

• 40:07Speaker 01

  But also, I mean, there are trophic factors as well that muscle releases. Remember, we talked about your son or whatever, you know, growing muscle, you know. Ultimately, when muscle is in that growth phase or change phase, it's producing hormones that's telling the rest of the body what it's doing. And then it also is probably telling our appetite sensors, centres and so on, what to do, what to eat, how to then like work together with the muscle to to enable growth, for example.

• 40:32Speaker 00

  That's something maybe about feeling tired. One of the things I definitely notice is I do the gym. If I've done a good session, like I get a sort of temporary high afterwards. And then a few hours later, you know, I'm at work in a meeting, I feel really tired. I think I need a nap. So there's some sort of linkage, I feel, from this exercise and I guess from these muscles afterwards?

• 40:52Speaker 01

  Well, it's fascinating. And there's something really interesting there about how we exercise and how we eat and how we sleep. Those things going together in the right order kind of like can lead to less feeling of fatigue. I think actually if you do it right and get all the stars aligned, then actually it can make you feel very energized.

• 41:11Speaker 00

  Any top tips for that?

• 41:12Speaker 01

  Well, I'm really interested in intermittent fasting and then exercise and then activity. I think that combined with good exercise in the morning in the fastest date helps me to keep much more alert and alive. I stop eating at eight o'clock at night and then I don't have anything until probably midday, I can let myself eat. And then I don't eat something really big then. I eat, you know, loads of veg and salad and fruit. And in that time, I do some exercise in the morning, just like a brisk walk and I stretch. But I, what I want to be doing, and this is my new sort of resolution from now, is I want to be really doing resistance training, sort of like basically sit-ups and and press-ups

• 41:57Speaker 01

  in the morning. I still can't do a proper full press-up properly, but I'm trying my best. I'm 51, you know, I need to be looking after my muscle health. And actually, you know, I don't think I'm doing enough at the minute.

• 42:12Speaker 00

  In addition to the exercise and how important that is for your muscles, I'm curious why you've decided that you want to do the exercise sort of before you started to eat for in the day. Is there any, any reason why you're doing that?

• 42:27Speaker 01

  Well, so it's partly because of just logistics. That in fact is the main reason. There's some interesting science about this coming out. So I'll be keeping my eye on that. It does have to fit into life for most people. And so this is what I sort of say to my patients, Jonathan, is do it when you can do it. Let's just really try and be active as much as we can and, you know, combine sort of aerobic type activities, but also resistance training activities, which don't have to take too much time. That's the good thing about them.

• 42:56Speaker 02

  I think it's breaking this rule. I mean, we were always told you must never do exercise without having a breakfast, right? It was terrible. You'd faint or you'd, you wouldn't make it. And that's clearly absolute rubbish. I always exercise before I've eaten. I'm like you, and I much prefer it. I now do a bit of resistance training, which I didn't do a couple of years ago. And I just fit this in. You'd only need to do 10, 15 minutes, you know, a session three times a week, you know, and I think it's, it is helpful.

• 43:24Speaker 00

  I'd like to maybe spend the rest of the podcast now talking about specific advice for what people can do listening to this. Do I only need to think about a healthy diet when I'm much older? Because that's the point when, you know, my muscles are starting to really become a problem.

• 43:45Speaker 01

  Well, no, I think what we've been talking about is the fact that this is a lifelong thing. I think thinking about it in your twenties, even actually as a child. I mean, one of the things I do is try and educate my kids because I want to set up good habits. So I think there's never too early to start to change your diet into being more healthy.

• 44:02Speaker 00

  And does it also mean that if someone listening to this is really serious about going to the gym and they are eating lots of protein, does that mean they aren't going to get the full benefits of their exercise if they aren't eating like a sort of a healthy diet around this?

• 44:20Speaker 01

  Protein is important. We have to eat protein in order to have our muscles healthy. And as I said, older adults might need a bit more protein than younger adults because of this anabolic resistance. But definitely chugging lots of protein drinks or eating exclusively protein is not going to do anything helpful for your muscles, partly because basically that's then just going to be used by the body as extra energy. It's not going to be used for muscle growth. It's going to be more calories, basically, that's going into the body and the body's then utilising. And secondly, it's just going to be, you know, pooed out, basically. People aren't going to absorb all of it. And there's some evidence that, you know, really high levels of protein actually are detrimental. We've

• 45:00Speaker 01

  seen that, actually, that if people are eating, you know, very high levels of protein, actually their muscle function over time is worse.

• 45:09Speaker 02

  It's worse?

• 45:09Speaker 01

  Yes, it's worse than if they were eating the right amount, which is between one and 1.3 grams per kilogram per day. But if you're eating a lot more than that, it appears that your muscles are not any more healthy, but actually probably less healthy. And that could be because actually you're exclusively getting your calories from those protein sources and you're actually not eating all the other things that are going to help your gut microbiome and everything else as well.

• 45:36Speaker 02

  Yeah, as we always say, it's instead of what?

• 45:38Speaker 01

  Yeah.

• 45:39Speaker 02

  It's really hard to go above 20% of your, all of your intake in protein. So we naturally revert back to fats and carbs. So it looks like we've got a sort of built-in system for most of us.

• 45:51Speaker 00

  When I go to the supermarket, everything has a label on it now saying added protein or high in protein. I imagine lots of people like me have ended up a bit confused about really what they should be doing.

• 46:03Speaker 02

  People can reassure that most people are already getting enough. They don't have to worry too much about it. As a rough guide, if you know what your weight is in kilos, as long as you're getting more than one gram of protein per kilo, you should be doing okay. And all of these extra drinks and things you don't need, and usually they're giving you ultra-processed contents, extra chemicals, additives, sweeteners, and nothing really nutritionally useful in it. I don't think you need to be eating meat every day. I don't, I have meat, you know, once or twice a month and my protein levels are fine. But my vegetables are high in protein. So I'm eating lots of beans and legumes. I'm

• 46:46Speaker 02

  eating mushrooms, plenty of fermented foods from dairy, have lots of protein in them. And you might sometimes have tofu and occasional bits of fish. They're all fine. So I think vegans have to be a bit careful and they should be carefully working out what their protein levels are. And some do end up being deficient. But for the average British person, yeah, I think if you are cutting back on your, your meat and dairy, you've got to just make sure you're filling your plate with all those, those plants that have so much protein to offer as well as fibre. And as Claire was saying, it's not just the protein, it's the other things that your microbiome needs that's really important. So that all

• 47:28Speaker 02

  that diversity of plants, that keeps the microbiome going well, which makes you more efficient in the way you make protein and muscle.

• 47:35Speaker 01

  Yeah, I definitely second that. And I think the other thing is, is that different plants have different sorts of protein in them. And what's really important is that you, you combine those different sorts of plants. So, you know, you always have some cereals, for example, whole grain cereals with some legumes, which then gives you the same sort of protein that a meat would give you. I think that's one thing about meat or, say, for example, eggs, really great source of protein, is that it's got everything in that single source. So that's why some people have perverted that. But you can definitely do the same with plant-based proteins.

• 48:09Speaker 02

  And realising that, you know, knowing a bit more about nutrition will tell you that having pasta rather than rice is much better way to get protein into your diet. Or whole grain pasta gives you even more protein than, say, something like white rice or potatoes.

• 48:24Speaker 00

  And so these just examples of foods that are high in protein that aren't sort of like my protein shake or red meat? Or are you actually talking about foods like specifically that should help to maintain my muscle strength because of, you know, what we've been talking about earlier in this show?

• 48:39Speaker 01

  So yeah, I guess a combination. So if you, so those things like whole grains and legumes, are they going to help your muscles? But they're also going to help your healthy gut microbiome. Whereas having sort of, you know, beef burger or whatever is only going to do the one, it's not going to do both. But I think the other thing that's really interesting about protein is that lots of studies that look at protein and muscle function really focus on muscle bulk or muscle or certain characteristics of muscle. But when we look at muscle function as a whole, it is a neuromuscular thing. And so we know that diets that impact the brain Um. Which is really important, brain and nervous system, really important for muscle function, actually, seem to be slightly different. And that's where some of these

• 49:22Speaker 01

  other things, you mentioned fish, but the other aspects of, say, for example, a Mediterranean diet, it's high in whole grains, high in fibre, it's high in fruit and vegetables, it's really high in things like extra virgin olive oil, which seems to have loads of polyphenols in it, which might be what's key. Nuts and seeds, and then fish, so fish being a component of the Mediterranean diet, um, which is quite, probably quite important for brain health.

• 49:48Speaker 02

  And not much pasta or pizza. So it's, it's, it's not what people always imagine.

• 49:52Speaker 01

  Yes, exactly.

• 49:53Speaker 02

  The diet to be.

• 49:55Speaker 01

  So those nuts and seeds and whole grains and legumes, yeah, which are really strong in the Mediterranean diet, those are all really good sources of protein. And they are also things that are going to help your gut microbiome, but also particularly your brain and, and nervous system health, which is really important for healthy movement. Then the polyphenols, that's probably super important for your gut function, but it's also really super important for nervous system function and that neurovascular bundle, that healthy nerve recruitment of muscle fibres.

• 50:23Speaker 02

  I think what Claire's highlighting is that we need to always look at these organs not as alone, but as part of a system, they're all connected. So if we go, as we always do in nutrition, very reductionist, and say, I've just got to have this artificial protein that's going to feed this particular bit of this muscle, you'd be missing a lot of the picture. You've got to be feeding the whole organ and its connections. And so that, you know, the, the idea that muscle is connected to the immune system and the nervous system and the gut, you've got to look after all of those if you want to be really maximising your benefit for muscles.

• 51:01Speaker 00

  You could think, I've got my car, so I've got to make sure the tyres are in fantastic shape and all sorted now. And that's sort of my protein is going to make sure my tyres are really in great shape. But actually, you know, if I don't fix all the other components of my car, then that's what's going to cause me to run off the road when I turn a corner. And so I think what you're saying is the protein is really important for growing the muscle fibre, but the whole thing is really affected by my overall immune system health and my low inflammation. And so as I'm thinking about what I'm eating, I sort of have to get all those components to work. Otherwise, it's like I've fixed my tyres, but I forgot to make sure the steering wheel actually moves. Is that?

• 51:41Speaker 01

  Yeah, I think that's a great analogy. It's, it's a complex system. Yeah.

• 51:45Speaker 00

  And Tim, can you paint me a picture for my son of what is going on inside him if he is on that sort of red meat and shakes diet?

• 51:54Speaker 02

  Yes. So it's a bit like people going on keto diets or carnivore diets. Short term, they might feel slightly better. You will see improvements in your muscle if you're young and you're exercising, but only if you're exercising at the same time. But gradually over the weeks, you'll see your gut microbes decreasing in diversity. Some of the good ones that are the only thriving on these fibres will be dying off. And they'll be replaced by these meat and fat loving ones that are generally pro-inflammatory, that then produce pro-inflammatory chemicals that stimulate your immune system and might eventually lead to, you know, more brain fog and you acting a bit more slowly and eventually getting

• 52:38Speaker 02

  more tired. So long term, you're doing some damage to your gut and the rest of your body at the expense of building up big muscles.

• 52:48Speaker 00

  That doesn't sound like a good place to be.

• 52:50Speaker 02

  No. What we need to find is a happy medium, which, you know, someone who does want to be sporty and have big muscles, also needs to remember to look after their gut. And they still need to have that same diversity.

• 53:05Speaker 00

  So we talked a lot about diet, but I'm pretty sure, Claire, you're going to tell me that nonetheless, that isn't enough to keep my muscles healthy and we also need to do exercise.

• 53:17Speaker 01

  Yeah, yeah.

• 53:18Speaker 00

  Are all forms of exercise the same in terms of the effect on our muscles? But also are they all the same in terms of their effect on our gut microbiome? When I hit forty, I started feeling tired and sluggish. I remember thinking, great, this is it. It's all downhill from here. But I was completely wrong. It wasn't my age, it was my diet. It was literally sapping my energy. I was trying to juggle kids, work and exercise. And back then I'd just grab whatever food was nearby. I still have that crazy schedule. But what's changed is what I put in my body. Our own research at Zoe has shown that if your digestion feels off, or you're regularly feeling exhausted, it's

• 54:00Speaker 00

  often because your gut bugs are starving. They thrive on a huge variety of plants, at least thirty different plants a week, and the more, the better. But if you're as stretched as me, it's not always easy to achieve this. And that's exactly why our scientists developed Daily Thirty. It's a great tasting gut health supplement with over thirty plants in every single scoop. I take it every day without fail. And because we're Zoe, we don't just guess, we test. We put Daily Thirty through a randomised controlled trial, the gold standard of testing. The results absolutely blew us away, proving it's good for energy, digestion and gut health. That trial helped us develop the formula that we have today. So if you're not feeling like yourself, don't settle for feeling sluggish. Head to Zoe dot com slash

• 54:45Speaker 00

  Daily Thirty and try it for yourself.

• 54:50Speaker 01

  Resistance training is really interesting because it's a really good way to build muscle. It seems to really stimulate the muscle in a way that some other training methods don't. I think resistance training needs to be part of the package, but in the same way, like, um, a bit like the diet sort of has to have a bit of variety in it. I think it's a good idea that your physical exercise regime has some variety in it. Getting your heart rate up, getting a bit sweaty, being a bit breathless in whatever you're doing, even if it's just walking briskly up a hill, try and get out forty five minutes three times a week. Old routes as well, they really benefit from balance training, sort of strength and balance. Um, and that's partly because balance is sort of really super

• 55:32Speaker 01

  important for function in later life and helping prevent falls. And that requires slightly different exercise regime.

• 55:39Speaker 00

  Tell us what you do, Tim.

• 55:40Speaker 02

  Yeah, I used to just, uh, go for a run or go for a cycle. I didn't do anything else. And now I'm particularly worried, you know, about dementia and, and cognition problems. I've gone for this diversity of exercise. On the one hand, to sort of make sure that I'm looking after my heart and my muscles, but also looking after my brain, because there's some evidence that the more different things you're doing, the more you can keep all the different bits of your brain active. So this morning I did some yoga, you know, two days ago, I did some pilates. I'll get on my Peloton bike another, another

• 56:19Speaker 02

  morning. Um, and I would sometimes do exercise classes with weights. Uh, and, you know, I'm obviously walking and, and in summer I'm doing a lot of swimming. And as you said, you know, balance becomes increasingly important as you get older. So, you know, can you stand on one foot? Can you get off the floor without using your hands? You know, some of these, these things are actually really important and.

• 56:44Speaker 01

  Yeah, yeah. The really good one for everyone to do, everyone do this from now is, um, stand on one leg when you're brushing your teeth and do some squats if you can. If you can't do squats on one leg, just, just do it with two legs. Squats while you're brushing teeth, that's probably enough to, to really build your muscles, actually, if you do it every time you brush your teeth.

• 57:02Speaker 02

  It probably also helps your brain as well, doesn't it?

• 57:03Speaker 01

  Yeah. The, the other thing really wanted to emphasise to people is stretching as you get older. Stretching is super brilliant at reducing the risk of injury when you're doing exercise. Um, and it's also really good at stopping sort of those awful things like back pain that stops you moving around. If you make sure you're stretching, preferably every day, doesn't have to be for very long, but it can really make a difference because our, um, our tendons just get so much less stretchy as we get older.

• 57:34Speaker 00

  Finally, Claire, for someone who's listening to this and is like, you know what, I, I want to do more to support my muscle health now. What's the one sort of thing that you would say, you know, start today?

• 57:46Speaker 01

  Those squats while they're brushing their teeth.

• 57:49Speaker 00

  Tim?

• 57:50Speaker 02

  I would say do something as soon as you wake up. Just five minutes stretching in the morning before your brain can say no. And get into a habit of doing something different every morning.

• 58:02Speaker 00

  Amazing. I'm going to try and do a quick summary. The first thing that comes to mind is muscles are crazy more important than I'd realised. So apparently they help prevent cancer, they help prevent me getting dementia. I mean, who knew this stuff? I thought they were just for walking around. There's this amazing study that you did, Claire, where you said that people who are following the Mediterranean diet actually have more leg explosive power. And I like the idea of having leg explosive power, but the idea that what you eat could actually change this is also remarkable. You need to do something for muscles, you need to do some exercise. And sadly, over time, though, these muscles are falling away. And this starts only already in your thirties. I think you said like two to 5% is being lost every decade.

• 58:47Speaker 00

  And so unless we really do something, then later in life, it's really going to prevent us having quality of life and maybe even have, you know, sort of life altering fall. But there's some really good news. You said that there were these studies where people doing lots of exercise in like their seventies or eighties and they managed to get their muscles back to a 20 year old, which I love. And as I get older, I find all of those studies more and more positive. And you did also mention that women have a higher risk than men because they have less testosterone, so even more important there. And then we talked about what you can do. And I think one of the most amazing things is this idea that you can eat a healthy diet and that can actually help to support your muscles and that we now understand that your microbiome is a really important part of this. And so sort of supporting the right bugs can affect your muscles, partly directly

• 59:31Speaker 00

  and partly because it has this big impact on your inflammation and your immune system. Protein is really important for your muscles. And so if you aren't getting enough protein, that is a problem. However, most people are in fact getting around 1.2 grams per kilogram just with the diet they're currently having. So this idea that we're all really short of it, and that is the biggest problem, isn't really true. And instead, what you'd like to do is make sure you're eating a lot of foods that are high in protein that are also good for your microbiome. And I heard beans, legumes, mushrooms, particularly dairy that's fermented, which you were like yogurts and cheeses, eggs, tofu, things like this. But you've got to have that still as part of a broader diet.

• 1:00:16Speaker 00

  And this is back to this Mediterranean diet that Claire, you're talking about and looking at this study. So it's fitting in that also things that aren't high in protein, but are just really supporting your microbiome. So whether that's olive oil, nuts and seeds, you know, whole grains, all together, that is really shaping your microbiome, that's really supporting your muscle. And then last of all, I think most interestingly, what you actually do. So Tim says he now does a diverse set of exercises, you know, want to change every day. And Claire, I think really interesting, you've recently gone for proper intermittent fasting. You stop eating at eight o'clock at night. You don't eat again until midday. You always have a very busy morning with three kids, you're a professor, all the rest of it.

• 1:00:59Speaker 00

  At lunch, lots of like plants, you said, veg and salad and fruit. You do exercise in the morning in this fasted state and actually you want to do more. And your guide was, well, if you're going to do one thing, then squat while brushing your teeth.

• 1:01:16Speaker 01

  Do something that's easy for you that you can incorporate. I think Tim's advice to do it in the morning is a really good one because it is the time when things are less complicated. Maybe we can inject a new good habit.

• 1:01:28Speaker 02

  Make it a habit is the way to go.

• 1:01:52Speaker 00

  As you can imagine, hosting this podcast, running Zoe, juggling family life, it all keeps me pretty busy. So I try as best I can to stay energised and show up well in all those parts of my life by fuelling my body with the right food, by exercising and by adding a scoop of Daily 30 to my meals every day. If you haven't heard of Daily 30 yet, it's the gut supplement designed by our gut health scientists here at Zoe. It's made of over 30 high quality, handpicked plants, including seaweed, fungi and different types of fibre. Better yet, it contains ingredients to support gut health, digestion and energy, which is ideal for packed calendars and busy lives.

• 1:02:35Speaker 00

  Simply add one scoop a day to any meal for an extra boost of fibre and plant diversity. And because it tastes delicious on just about anything and adds a satisfying crunch, it quite quickly slots into your life, becoming a daily healthy habit you'll always have time for. By the way, whenever we talk about Daily 30 as a good source of fibre, we're required to say that it contains four grams of total fat per serving. Obviously, that's all amazing healthy fats from plants. So order yours today at zoe.com/daily30. Thanks for listening and see you next time.