The Wellness Scoop - Why Is Exercise Good For Us?

Episode Date: September 15, 2020

Dr Daniel Lieberman, a Harvard professor, talks us through why we’re over simplifying exercise in the modern world; why ‘just do it’ doesn’t work and why exercise really does matter. We look at how it’s connected to our mental and physical health, from coronavirus to depression; whether there is an optimal form or duration of exercise; how we’ve evolved – the biological and anthropological foundations of movement and whether sitting is the new smoking?   Book: Daniel Lieberman, Exercised Our app: IOS: https://itunes.apple.com/gb/app/deliciously-ella-app/id1445510165?mt=8 Android: https://play.google.com/store/apps/details?id=com.deliciouslyella.delella See acast.com/privacy for privacy and opt-out information. Learn more about your ad choices. Visit podcastchoices.com/adchoices

This is an ad from BetterHelp Online Therapy. We always hear about the red flags to avoid in relationships, but it's just as important to focus on the green flags. If you're not quite sure what they look like, therapy can help you identify those qualities so you can embody the green flag energy and find it in others. BetterHelp offers therapy 100% online, and sign-up only takes a few minutes.

Visit BetterHelp.com today to get 10% off your first month. That's BetterHelp, H-E-L-P.com. Hi, and welcome to the Delicious Yellow podcast with me, Ella Mills. So I have to say reflecting on today's episode feels a little bit funny in some ways as I'm currently quite literally waddling around. I'm 36 and a half weeks pregnant feeling quite a lot like a whale. So record this I'm actually resting the microphone on my belly. So the idea of sort of burpees, star jumps, running, HIIT workouts feels like a million trillion miles away. Exercise for me is trying to walk around the park with Skye and my little daughter and Austin our dog and doing some kind of gentle stretches and

things. That being said even that makes the world of difference and I'm just such a believer in the power of movement in any shape or form basically but as with anything I think understanding why we need those practices in our lives and what they can do to help us is so important to find a bit of motivation to do them and knowing that they have such impacts on our mental and physical health for me really makes the world of difference it also have so feels like the perfect time to be having conversation with an expert about this because we have also just finished recording loads and loads of new exercise videos for our app which will be live in the next week or two so if you don't have the app yet then basically it's a wellness made really simple and accessible

in your pocket on iPhone and Android. And it's over 600 plant-based recipes, 150 yoga and fitness videos, guided meditations, and so much more. And it's literally just 99p a month. We update it every single week. I'll pop a link in the show notes for anyone who wants to try it and you get a week's free trial as well. So if you feel motivated after this, learning about exercise to get moving and you want to do so in an easy way, then definitely try out the app. So today's episode is focused on exactly this, how to make exercise easy, accessible, enjoyable, and as a result, a genuine part of our everyday lives. And I just really want to understand why we need to do that, basically, and why we also need to bring more compassion to the conversation. It turns out,

listening to our expert today, that we haven't actually evolved to want to exercise to some extent. It's actually a very, very modern concept. And so it's a real honor to interview another Harvard professor this week. It's been two weeks in a row, and I have to say I'm feeling overwhelmed and humbled and honored to be able to speak to such educated, brilliant, informed people on the podcast. And through today's episode, we will be looking at whether there's an optimal form or duration of exercise, answering myths like is sitting the new smoking, looking at why it's okay not to want to exercise and how just do it doesn't actually really work for all of us, as well as understanding the links to ageing and our mental and physical health from depression to cancer, coronavirus, and Alzheimer's.

So I am honored to welcome Dan to the podcast. He's the author of the new book, Exercised, which is brilliant. Welcome, Dan. Thank you so much for joining us. It's my pleasure. Thank you. What constitutes exercise? Do you have to be moving for a certain amount of time? Because obviously you've got walking, which I'm assuming you need to do a little bit more of for it to constitute exercise versus like a 15 minute HIIT session. How do you constitute what counts? Well, there is no simple definition.

I think any form of movement is physical activity and exercise is simply physical activity for the sake of health and fitness. So just walking the dog around the block can be a form of exercise, as can be going for a hike or a run or climbing the stairs in your building or whatever that happens to be. There's no one definition of exercise. Sitting while watching TV and doing some sit-ups or stretching can be exercise. It's as varied as the kinds of physical activity that we do. And that's part of the fun of it. I mean, there's so many ways for us to move and be healthy.

There's no one way to do it. Some ways, of course, very stereotypical, getting on a treadmill, going for a walk, going for a run. Think about it. We buy weights whose sole function is to be lifted. That's a very modern phenomenon. Nothing wrong with that. If you enjoy doing it, you should do it.

Whatever makes you happy and fun. Going dancing with some friends, that's a form of exercise. So basically, everything, just move your body and that constitutes exercising. Absolutely, yeah. And there's such pleasure and joy in doing it. Gardening is a wonderful form of exercise. Yeah, something that people have been loving during coronavirus as well, I know definitely in the UK. So I actually, I'm going to go straight to the end of your book. And I absolutely love the

line in the epilogue where you say, all of us get one chance to enjoy a good life and we don't want to die full of regret having mislived it. And that really includes having misused our bodies. And you put forward so many incredible ideas about reframing the way we think about exercise. And I'd actually love to just start with the word itself, because I'd never really taken a huge amount of time to think about it. But you're really right in the way you say that actually the word itself can have quite a lot of negative connotations. And even going back as far as the fact that it was actually originally used to denote kind of arduous physical labor, like plowing a field. And then even more so, which I had no idea about, treadmills actually used to be used for convicts and condemning someone to trudge for

hours in the treadmill was actually a punishment in prison. Yeah. I mean, for a living, I put people on treadmills and I have to say hate them. And I've always hated them. And so I kind of used the treadmill as a kind of recurring theme throughout the book. Because I think a treadmill is sort of the apotheosis of exercise. It's a very strange machine we spend money on. It's sort of a commercialized and medicalized way of getting somebody to work really hard to get nowhere. It's a very strange thing.

I wondered if you could take us back to your thinking about where we are when we think getting somebody to work really hard to get nowhere. It's a very strange thing. I wondered if you could take us back to your thinking about where we are when we think about exercise and the paradoxical nature of it in today's society. Well, we evolved to be very physically active, but also to not be active when it wasn't necessary or fun. So for millions of years, our ancestors were hunter-gatherers, and after that, they were farmers. But these are hardworking people who have to labor to get every calorie they put into their bodies. So they work fairly hard. No, hunter-gatherers don't work crazy hard. They work a few hours a day, walking and carrying and sometimes running and climbing trees and digging and all those sorts of things that are necessary to get food every day. But otherwise, in a world without Sainsbury's and Marks and Spencers or whatever, there's no way to get extra calories. So they hang out in a camp and conserve energy.

And we live in a world today where we can just walk around the corner and purchase foods that are loaded with calories and never have to get our heart rate up. And so we have to find new ways to be physically active because it really is healthy. Can you tell us a bit more about that? Just to kind of, I guess, circle back and start with what you mean by it is healthy, but we're sort of slightly doing it wrong. Is that kind of the premise of what you're saying? Well, I'm not sure that we're necessarily doing it wrong. I think that our approach to exercise hasn't really necessarily worked for everyone. I mean, exercise right now is something that's

become a privilege of people who are wealthy and have time and aren't commuting and don't have the stress of daily life and also have sort of the wherewithal to go to a gym or what have you, because in a kind of strange sort of paradox, people used to have to be physically active in order to survive. And that was really important for our health. And we can go into why that's the case, but our bodies are mismatched to not be physically active. So people who aren't physically active throughout the life cycle, when they're children, in order to develop appropriate capacities and skills. And as we continue to age, physical activity, exercise remains incredibly important. It slows the aging process.

It prevents incredible range of diseases. You know, it promotes health in a wide range of ways and for very interesting reasons. And when we cease to be physically active, we make ourselves much more vulnerable to disease and we age more rapidly. So in the modern world where we don't have to be physically active, we have to find ways to help each other be physically active, but recognizing that exercise is really a very abnormal modern thing. And there's a reason people don't like to do it. And what is that? It takes energy. You know, if you put a stairway next to an escalator, right, you know, like as in a, you know, a tube stop or, you know, in a shopping mall, right? Worldwide, no matter where you are, whether you're in the

United States or England or Japan or Israel or Denmark, all the places they've done this study, just about 5% of people willingly take the stairs. Almost everybody takes the escalator. If you put the escalator in the Kalahari Desert or in the Amazon jungle, people there would still take the escalator because it's an instinct to save energy when you don't need to use it. The equation of life is pretty simple. The equation of life is really energy in, babies out. That's what we evolved to do, right? To take in energy and then use that energy to reproduce. We didn't evolve to be healthy. We didn't evolve to be happy. We didn't evolve to be nice. We evolved to pass on our genes to the next generation. I know that's a very reductionist view, but it's basically true.

And so there are deep and fundamental instincts not to waste energy, which is why most people, when given the choice between sitting on the couch or in a chair and going out and doing a completely unnecessary five-mile jog, will sit in the chair. So you've got 10 myths in the book, which are brilliant. And one of them is exactly that, which is that the just do it slogan is a bit of a myth and that actually it isn't natural in us to want to do that. So we shouldn't kind of chastise ourselves for not wanting to exercise. That is in fact a very normal kind of biological instinct. Yeah. I mean, it's just like blaming

people who have trouble dieting. Dieting is also an abnormal thing. I mean, we never evolved to lose weight because nobody in the past ever had to. It was always an adaptation, a benefit to gain more weight. And the same is true of needless discretionary physical activity. It's a very strange thing. Now, of course, we do it for play. We do it when it's fun. We dance.

But standing on a line and running 26.2 miles to another line as fast as you can is a really bizarre and strange thing. And calling somebody lazy for not wanting to do it is the height of being unfair. It's normal to not want to do it. But it's also abnormal not to be physically active. So we need to find compassionate ways to help each other without blaming each other. And I think that the modern approach to exercise where we've essentially commercialized and medicalized it, you know, there's nothing wrong with commercializing things or medicalizing things. I mean, exercise is medicinal and I buy fancy exercise gear, et cetera, but it doesn't completely work,

right? And the data show that, right? The vast majority of people in countries like the United States and England want to exercise, but the vast majority of us fail countries like the United States and England want to exercise, but the vast majority of us fail to exercise. And it's not because we're lazy. It's because we're fighting against deep, basic, fundamental instincts. So how do you change that? Well, I think there's a number of ways. And I think one of them is to, there's a whole chapter in the book where I try to take a sort of an evolutionary anthropological approach to that problem.

And I think we have to go back to basics. And I think the basics are that we evolved to be physically active basically for just two reasons. One is when it's necessary, and the other is when it's fun. And I think the best way to make physical activity or exercise necessary and fun is to make it social. Again, let's go back to treadmills. You go to the gym and you see people sort of using a treadmill a bit like the way they take cod liver oil. It's

unpleasant, right? So they put on headphones or watch a movie, et cetera, and that can help relieve the tedium, but nobody really enjoys it, right? So we do things to kind of make it tolerable, like listening to a podcast. And I do that myself when the weather's really bad. So that's one way to make it fun. But I think an even better way to make it fun is to do it with friends, right? Walk in a park with friends or go for a jog with friends or play a game of football or whatever it is that you enjoy doing. And there are many things. And I think we as a society need to find more ways to help make physical activities social and enjoyable.

I think if we do that, we'll succeed in helping people. We also need to make it more necessary. In schools, for example, there's just not enough physical education in schools and universities have mostly completely abandoned this role that it used to be an intrinsic part of education. And, you know, the list could go on, right? There are all kinds of ways in which we can get institutions and governments to be involved. A good example is your prime minister, Boris Johnson, right? Who for years wrote, you know, excoriating sort of screeds against the nanny state. And now he's had a near-death experience with COVID-19 and kind of woken up and realized that not only is, you know, fitness and health are woken up and realized that not only is fitness and health really

important, but also that government needs to play a role in helping people. And so he's now trying to get the National Health Service to prescribe exercise if appropriate to their patients. And that's good. That's what we need to do. We need to wake up. And is there a kind of optimal dose and type of exercise in order to have that impact on our health? Well, that's one of the myths that I tackle. And the answer is absolutely not. There is no optimal form of exercise. And there's no simple formula either. And that's part of the problem with, I think, the way we often convey information about science and health, you know, 10 steps to this or five steps to that. We try to make it easy and

simple. And the fact of the matter is it's never really easy and it's never totally simple. And if you think about optimal, what are you trying to optimize? You're trying to optimize your longevity, you're trying to optimize speed, or you're trying to optimize weight loss, or you're more interested in metabolic syndrome, like diseases like diabetes or heart disease. There's no one benefit from physical activity. And so for everyone, those needs are different and their fitness levels are different and their age is different and their backgrounds are different. So for everybody, it's different. So there's no one formula. There's no one prescription. What we can say, however, is that

some is better than none. And then as you increase the amount of exercise you do, you get additional benefits, but those benefits tail off. And at a certain point, you know, you're not getting any more benefit from additional exercise. And there's a big debate about whether or not you can exercise too much, but there are very few people in that category. So I think we can not worry about them. I think it's the same in the US and the UK that you're kind of, we're sort of encouraged to do a kind of base level of about 150 minutes a week. And then there's a lot about 10,000 steps. Where do those figures come from? Those are consensus statements made by, you know, a number of major health organizations, the World Health Organization, Department of Health and Human

Services, the American College of Sports Medicine, the American Heart Association, pretty much everybody has converged on this sort of baseline of, which is 150 minutes a week of moderate exercise, 75 minutes a week of vigorous exercise. So moderate is sort of, you know, you can talk while doing it. Vigorous is where it's kind of hard to really, you know, have a good conversation while you're doing vigorous exercise, but it's based on heart rate. And you should also do some weights, like maybe twice a week. So those are what we consider sort of the baseline. And that's based on big, large epidemiological studies involving hundreds of thousands, millions of people really actually now, where you can look at the relative risk of death on the Y-axis against

essentially how much dose of exercise on the x-axis. And if you engage in that kind of level of exercise, you can essentially reduce your relative risk after correcting for age by about approximately 50%. So that's where that number comes from. But if you look at that graph, if you did half that amount compared to nothing, you'd still get some benefit.

And if you did more than that amount, you'd get more benefit. So there's no one number. It's just kind of a conventional benchmark that helps people come up with something that's attainable. If you think about it, 150 minutes a week is just 21 minutes a day. So really all they're asking is that people get out and walk briskly 21 minutes a day. Is that so hard? And yet many of us really have a hard time doing that because it's not really very instinctive to do it if you don't need to. And if you talk a bit about kind of speed versus endurance and how kind of HIIT training, which I know is very popular, fits into that and that

it's not really about being the kind of tortoise or the hare. How do the two kind of compare? Well, again, you know, we love to simplify things, right? And people come up with a formula. And so right now there's a lot of interest and for very good reason in HIIT, right? High intensity interval training, where basically you go through sort of short bursts of really getting your heart rate up for 30 seconds or a minute, really put the treadmill up at the maximum speed you can run at or something like that. And there's a lot of evidence that that kind of interval training has a huge benefit. You get a lot of bang for your buck, as we say here in America, from HIIT training. But nobody really got fit doing just HIIT training, right? And what we're finding

is that just like our ancestors, you also get benefits from trudging along for a long time, and you also get benefits from occasionally lifting weights. There are lots of different ways to get your body active, and it shouldn't be a surprise that mixing it up is really good. The main reason exercise is good for us is that it's stressful. It's tough on your body, right? You elevate your heart rate, you increase your blood pressure, you produce all these reactive oxygen species, which can kind of wreak havoc in your body. You elevate your temperature. It's a stress. But the reason that exercise is good is that our bodies then respond to that stress, right? We produce vast quantities of

antioxidants. We regulate our autonomic nervous system to regulate that fight and flight response that's elevating our heart rate. We produce proteins and enzymes that sort of clean up the damage. And the interesting thing is that we don't turn those repair and maintenance mechanisms on as much if we don't exercise, right? If we're not physically active, that's because you don't want to turn these things on unless you need to. And so what's really good about high-intensity interval training is that it really stresses the body really hard. So it really turns up those responses and you get a very healthy, beneficial response. The metaphor I like to use is, it's like, imagine you spill some coffee on the floor, and then you clean up the floor, and then the floor is actually a little bit cleaner than even before you spilled the coffee. You get kind of a net benefit. And again, mixing it up

gives you different benefits. Stressing your muscles gives you a different benefit than the cardiovascular stress from aerobic exercise. So that's why mixing it up is good, because you want to stress different systems of your body in different ways. And the end result is something that slows aging and keeps us vital and healthy and reduces our vulnerability and susceptibility to an extraordinarily wide range of diseases, including, by the way, COVID-19. Interesting. So what's the connection with COVID-19 then? So COVID-19 is a respiratory tract infection. It's a virus that we mostly inhale. You can also get it through other entry points, but inhalation seems to be the major way we get it. And when you exercise, one of the things you do is you upregulate parts

of your immune system to kind of defend you against potentially negative consequences of being out there and physically active in places where you might get an infection. And so it turns out you produce more immune cells. There are certain kinds of cells called natural killer cells and others called cytotoxic T cells. And they sound scary and horrible because they are, that is if you're a virus. And you produce more of these cells and you actually send more of them to the vulnerable parts of your body, to the mucosal linings of your respiratory tract, for example. You also upregulate your ability to produce antibodies. So if a vaccine comes around, go for a good run before you get the vaccination. It'll give you actually a boost in terms of your immune system. So our bodies evolved to respond

to the stress of physical activity and also the vulnerability of physical activity by turning up our immune system. So it's vital. There's, of course, a debate as to whether or not you can exercise too much. And there might be, it's very debated right at the moment. But if you went and ran, like, say, a marathon, you might sort of open a window for a little bit more vulnerability to infection because you've used so much energy. But again, very few of us are in that category. Interesting. And what about the link to sort of other diseases like cancer and cardiovascular disease? Oh, I mean, there's almost no disease that's not helped prevented or sometimes even treated by exercise. I mean, cardiovascular disease is probably the poster child. I mean, there's a reason we call aerobic exercise cardio. It's really good for your entire circulatory system. It strengthens

your heart. It helps you produce more capillaries and blood vessels throughout your body. So you actually lower blood pressure and arguably high blood pressure is the major cause of death in the world today. It decreases your levels of bad cholesterol. It's no secret that aerobic exercise is really important for your cardiovascular system. It turns out that physical activity is also very important for a number of cancers. Now, not all cancers, but there are quite a few studies which show that you can, for example, women can decrease their likelihood of developing breast cancer by as much as 30 to 40. Some studies even suggest 50% by physical activity, by just moderate levels

of physical activity. And that's partly because you reduce the amount of estrogen and progesterone that are circulating that are mitotic and can increase your chances of cancer. You can really vastly decrease the risk of colon cancer. And there's a whole series of mechanisms by which we think this occurs, partly by upregulating the immune system, partly by decreasing levels of glucose in the blood, partly by decreasing levels of inflammation in the body. There's no one single pathway, but there's numerous pathways by which physical activity affects your cardiovascular system.

It affects your vulnerability to cancer, metabolic disease, Alzheimer's. If you're concerned about Alzheimer's, by far the best way to prevent Alzheimer's is by being physically active. Nothing comes close, nothing. And then on the flip side, because there are other kind of myths that you addressed, which I think are really important. I think it's like, you know, and it's a line I think we've all heard a lot of time. It's like, is sitting the new smoking? Is it a myth that sitting is kind of intrinsically unhealthy? And you also quite quick point out that actually, like, there's an importance in inactivity as well. And good things happen when we take it easy

on the flip side. Yeah, I mean, we have such a simplistic approach to exercise, right? We get so hot under the collar about physical activity, we start demonizing chairs. I mean, but I'm sitting in a chair right now, and I don't think it's killing me. And if you went into a hunter-gatherer camp, they'd be sitting as much as you and I. They sit on average about nine hours a day. You can't exercise all day long. It's not possible, and it's not probably even healthy to exercise all day long. We react so strongly to the things that

we're scared of that we, I think, sometimes oversimplify. And in oversimplifying, we get things wrong. So sitting isn't intrinsically bad. Sitting too much, however, is a problem. And it turns out that there's not that much association, if you look at epidemiological studies, between how much you sit and your vulnerability to disease, that is how much you sit at work, it's really leisure time sitting that turns out to be most correlated with disease. So people who don't exercise after they get off work or don't walk to work or whatever, they're the ones most vulnerable. Because if you're physically active and sit, that's not necessarily a bad thing to do.

And the other problem is sitting for very, very long periods of time without getting up every once in a while. So there's pretty good data which shows that long bouts of uninterrupted sitting are inflammatory and problematic. So if you think about it, the way we evolved to sit is to be in camp and every once in a while get up and tend the fire and take care of kids and just sitting completely inertly in chairs with backs for long, long periods of time aren't good for us. So there are ways to sit more healthily, but let's not demonize sitting. Yeah, absolutely. And what is a long period of time to be sitting? Well, you know, again, there's no simple answer to that. But it looks like the data suggests that, you know, you should get up every 10, 12, 15 minutes, right? Very long periods of time sitting with no interruption.

A good analogy is like turning on your car, right? When you turn your car on, even if the engine's not running, you're still getting the motor working and stuff is happening and filters are being turned on, et cetera. And the same thing is true with your muscles. Even if you get up and walk around the room and you're not running a marathon, you're still using up some glucose in your bloodstream. You're burning some of the fats in your bloodstream. You're kind of waking up your metabolism.

You're kind of turning on various functions, and that seems to have a good effect on preventing inflammation, which is kind of the slow burn of your immune system that's really unhealthy. So just kind of being, you know, moderately active every once in a while is good for us. I mean, just think about the chairs that we sit in, right? Right now, you and I are probably sitting in chairs that have backrests.

But until recently, only the king and queen and the pope and grandees could have chairs with backrests. The rest of us sat on the floor on stools or, you know, benches. It's only in the 19th century that chairs with backrests started getting mass manufactured and most of us could finally sit without having to spend even a single calorie. But sitting used to be more active. So if you can sit slightly more actively, you get a lot of benefit. That doesn't mean you shouldn't sit. But good things also happen in your body, don't they, when we are inactive? We shouldn't just see ourselves as lazy.

We need rest just as much as we need to move. Oh, absolutely. And in fact, in a normal person, you spend more energy resting than being physically active. Inactivity is not totally a state of doing nothing, right? When you're inactive, all kinds of things are happening. You're digesting your food. You're repairing things. You're maintaining your body.

Every tissue and cell in your body benefits from rest. That's why we need to sleep. When we sleep, we clean out our brains, we store memories. I think it's ironic that we're told to exercise more and that sitting is bad for us and we should sit less, but we should also sleep more. That doesn't actually make a lot of sense if you think about it, right? So rest is important. It's just if we only rest, well, then we get into trouble. You've mentioned aging, and I'm sure that's something that people will be very interested in. You said it's a myth that it's normal to be less active as we age. What's the link between

aging and desire to exercise and impact of exercise? And should what we do as our exercise shift? Well, so this is one of the things that I'm most interested in. We're actually trying to do a lot of research on this right now. But, you know, the idea that as you get older, you can kind of take it easy is a really modern idea. And in fact, I argue in the book that we evolved not only to age well, but to be physically active when we age. So most animals, almost every animal on the planet is unable to survive past their reproductive

lifespan. So chimpanzees and other mammals are unable to have offspring. There's no selective benefit for them for being around anymore, and they die. We're one of the few animals that evolved to be grandparents. Killer whales are another example, but there are almost none on the animal world. And the reason we evolved to be grandparents, and I call this the active grandparent hypothesis, is that grandparents play an important role in foraging societies in working really hard to get food for their offspring. So grandparents aren't sitting around in camp or going to Florida or Spain or wherever it is you might go to kind of go on

retirement. They're actually out there hunting and gathering and digging and preparing food and taking care of kids. They're helping their children and their grandchildren. And in fact, in many of these hunter-gatherer societies, grandmothers are more active than mothers because they don't have the same childcare duties. And that physical activity is, just as we talked about earlier in the conversation, is really important because it turns on repair and maintenance mechanisms, right? And you know this because your metabolism is actually elevated after your exercise. We call this, sometimes it's called the afterburn. For hours after you're physically active, your metabolism is slightly elevated. And that slightly elevated metabolism

is evidence of all kinds of mechanisms that are repairing your brain and producing proteins that are good for sending in memories and improving your blood supply and wiping out reactive oxygen species and all those other things that happen when we're physically active. And, you know, study after study after study shows that physical activity is important throughout the lifespan. But if there's any one time when it may have the most bang for your buck, right, it has most effect on vulnerability to disease and aging as we age. So it's even more important to be active as we age, not less important to fight the aging processes. And think about all the people we know who have managed to survive into old age and are still vigorous and don't have a lot of illnesses and disease. I guarantee you, if you think about them, these are mostly pretty active people.

These are not people who sit in bed all day long and just watch the telly. Yeah, absolutely. And you mentioned there about how exercising speeds up metabolism. they're not people who hang out who sit in bed all day long and just watch the telly yeah absolutely and you mentioned there about how exercising speeds up metabolism there seems to be like as far as i understand an ongoing debate and a lot of confusion around weight maintenance and weight loss and exercise and whether or not exercise can support weight loss or whether it makes no difference at all which i've always found a very confusing concept. And I wondered if you could shed a bit of light on that. Yeah. Well, anybody who isn't confused doesn't understand what's going on. It is confusing. So I devote a whole chapter in the book to this. So it is true that if you want to lose weight, you're much better off or you're

more effective if you diet than exercise. Because I just went for a run this morning, I ran about 10K, right? So I probably burned about maybe 600 calories, which is a fair amount, right? But if I had denied myself a big milkshake or two sodas or something, I could have not had the same caloric effect, right? So you can much more easily, by not eating dessert and giving up sugar, lower your calories through diet than through exercise. Because the exercise just doesn't burn as many calories as you can avoid by not eating highly caloric foods. So there's no question that exercise is less effective for losing weight than diet. So that has led some people to argue that exercise is kind of useless for weight loss.

And people have also pointed out that when you exercise, you're also more hungry and you're tired. So you might be less likely to move for the rest of the day. And also you're going to more likely to reach for that Coca-Cola or that Chelsea bun or whatever it is you want to eat afterwards to restore those calories. And the studies show that to some extent, the compensatory eating is true, right? We are more hungry after we exercise and they're not immediately. But people tend not to eat as much as they exercise necessarily, and you can control that. And as for the other sort of laziness compensation, that turns out not to be true. People who exercise don't tend to be more inactive for the rest of the day. So it turns out so that moderate levels of exercise can help you lose weight. It's just

they can't help you lose weight rapidly. So just a regular regime of walking, or if you can do something more vigorous, you can lose weight. You're just not going to lose it quickly. But there's nothing wrong with that. Sometimes I think we're in too much of a rush to do things. And sometimes maybe the healthiest way to lose weight might be to do it slowly and gradually. And then the other really important point is that physical activity turns out to be incredibly important for preventing weight gain or weight regain. So one of the big problems with dieting is, and we've all seen this, we've all experienced it, you lose weight and then it comes back again. And that's partly because your metabolism is altered and just comes roaring back. But study after study has shown that physical activity plays a really critical role in preventing

that weight regain from a diet or preventing that weight gain in the first place. So dieting certainly has its place in weight loss, but exercise also is an important component of the process. And plus you get all kinds of other benefits from exercise that you don't get from dieting, all the other health benefits. So again, it's a way we oversimplify things. We focus on, you know, do this, not that. Well, it's really best to do both. You just mentioned there about other benefits, and we've obviously talked about the physical

benefits and the link to a lot of physical disease. But there seems to be a lot of conversation at the moment as well around the benefit of moving our bodies on our mental health as well, and depression and anxiety and kind of a lot of the afflictions of the modern world. Oh, I'm so glad you asked that question. This is so important. And I think for many people, really, it can and should be a primary motive, right? Because physical activity has enormous effects on our mental health. And we know this at every level. We know the mechanisms and we have big studies which sort of show the correlations. Exercise affects neurotransmitters like dopamine and serotonin, making us feel more rewarded and happier,

hence having huge effects on depression, also potentially affects on anxiety, although it seems to be less effective for anxiety than depression. Exercise affects other neurotransmitters that affect mood in all kinds of ways. You produce opioids and endocannabinoids and epinephrine, and it's an incredible mood enhancer. Of course, we all know that from our own experiences. And I think one of the problems of the modern world is that so many people are inactive and they don't get that mental health benefit from physical inactivity. And then we kind of lose that kind of vitality. So there are immediate mental health benefits from physical activity that surely play into

a lot of the mental health issues that we face today, especially during this pandemic when we've all been driven inside and we're sort of starving for anything that will help our mood, right? Exercise is absolutely one of them. It also improves sleep. It decreases our stress levels. This is something that we didn't already know. I mean, I think everybody knows that exercise is good for them, but I think the science is really fascinating and I think compelling. Yeah, absolutely. And as you said, it's also such a great motivation

to get moving. And that's what I wanted to kind of ask you. There's obviously so many reasons to exercise. But then, as you said, at the beginning, we've got this difficult relationship with exercise where we're not necessarily biologically evolved to want to exercise and be really excited about getting on the treadmill. And, you know, how do we kind of bring in everything that you've shared and that you've learned looking back at the kind of evolutionary anthropological elements of this and understanding like how our brains, how our bodies work, how do we use all of that to reframe our thinking in order to take on board a much more positive approach to it, make it a bigger part of our life and then start to reap all those benefits, not just for ourselves as individuals, but as a society,

you know, we'll probably all benefit from massively for our healthcare systems and so on and so forth if we all were able to do it just that little bit more. Yeah. Again, I think the most important message of this book is to help each other acknowledge that exercise is abnormal. But so are lots of other things in the modern world. Think about reading, right? And education. Those are also abnormal. Until a few thousand years ago, nobody read, right? Because there was nothing to read. Writing hadn't been invented. You know, education, going to school is a completely modern thing, right? But none of us question whether education and reading are good for us and good for our kids.

We recognize that. And so we've created all kinds of social structures and systems, institutions to help make education fun and useful and necessary. And exercise is no different. It's also a modern behavior that didn't used to exist in the ancient world. Of course, people were physically active, but they were physically active because they had to be, or they did it when they were dancing and for other reasons that were fun. And I think we need to treat exercise the way we treat education. Recognize

that it's something that's beneficial, but modern. And then use the kinds of social structures that we create to help each other and compassionately without blaming and shaming and getting each other exercise. That's why I call the book Exercise because we get exercised about exercise. And again, I go back to these very simple principles, which is that we evolved to be physically active when it was necessary and fun. And so if we're going to help each other, we need to compassionately help make it necessary and fun. And that means making it social. And that means providing incentives. And there are all kinds of ways to do that. And in the book, I try to outline fun ways to do that. And everything from dancing and playing and sports to running groups. And there are so many ways of doing this. And we can even use a method called commitment contracts, which is, I think, a very interesting

experiment, right? I'm a professor, right? There are all kinds of students in my school who pay ridiculous sums of money for me to make them work really hard, right? And if they don't, I give them a poor grade, right? They suffer. We can even kick them out and they become humiliated, right? And they willingly enter this contract because they know it's good for them. And we can do the same thing for exercise. We can have people enter commitment contracts where they can set a goal or a level for themselves and we can have referees, they can have friends or relatives, you know, act as a referee and then get some kind of benefit from it. They could even just get their own money back, for example. There are all kinds of creative

ways that we can help each other. One of the ways I exercise, I mean, when I go out for a run in the morning, I don't ever want to leave the house, but I often run with a friend. And if I don't meet the friend at 6 a.m. at the local pharmacy, he's going to be really pissed off at me and vice versa. So I find ways to coerce myself. And we all need to incorporate that in our lives and help each other do that. Yeah, so make ourselves more accountable. Yeah, and be compassionate and helpful rather than engage in the kind of blaming and shaming that I think is counterproductive. I mean, nobody likes to be nagged to exercise. Nobody,

not even people who love to exercise. And so nagging people to exercise, telling them to just do it, is clearly ineffective. Well, Dan, thank you so much for your time today. I'm definitely inspired to get up after this and walk around a little bit, take the dog out and not sit still for too long. Thank you so much for inviting me. So appreciate your time. The book, Exercised, I'll put all the details in the show notes below. If this is an area you're interested in, it's absolutely fascinating and really, really, really recommend it. Otherwise, we will be back again next Tuesday.

Thank you all so much for listening. You're a podcast listener, and this is a podcast ad heard only in Canada. Reach great Canadian listeners like yourself with podcast advertising from Libsyn Ads. Choose from hundreds of top podcasts offering host endorsements or run a pre-produced ad like this one across thousands of shows to reach your target audience with Libsyn Ads. Email bob at libsyn.com to learn more. That's B-O-B at L-I-B-S-Y-N dot com.