Transcript

00:00 A lot of people exercise because they believe it will help them to lose fat one of the biggest debates on the planet. What advice have you got for me. So this is not a well-known fact but Daniel Lieberman he studies and teaches. Humans are supposed to live author and professor at Harvard University exercise disease sleep nutrition. He has the answers and all of those things that most of us care about we evolve to be very. Physically Active working in the fields hunting Gathering but now we live in a world where only 50 of Americans ever exercise and the rest of the world is headed. Our way cancers. Depression anxiety can attribute that to less physical activity in fact women who get 150 minutes of physical activity. A week have a 30 to 50 percent lower breast cancer risks and it's crazy right. The problem is that we spend three percent of our medical. Budget on prevention and yet 75 of the time. The disease is a preventable disease. It's a completely backward stupid system when you started writing this book about exercise was there any instant changes that you implemented into your own life strength training. The more I study the importance of doing weights especially as you age. The more I started kicking myself for being lazy about that. When people retire they're become less active. They tend to lose muscle and then that starts off a vicious cycle so would you say we shouldn't retire. It's a very modern Western concept and yes we do pay a price for it. So how does one go from having a negative opinion towards exercise to becoming an exerciser as an evolutionary biologist. There are multiple ways of doing that so Daniel what are some of the biggest myths within exercise gosh. There are so many one of the most common of course is Daniel Lieberman. He's been to every corner of the world visiting native tribes to understand how humans are supposed to live and now he has the answers and all of those things that most of us care about on sleep nutrition exercise disease you know on disease. He says that 74 of them can be prevented and he knows how to prevent them aging running are we born to run. He tells me the story of a CEO that forces his employees to exercise and the impact that that's had on that company and he talks about how as humans we've evolved to either use it or lose it. So maybe maybe retirement is a really bad idea for many of us. One of the most thought-provoking pivotal conversations I've had on the show you're really going to take a lot from this one and I suspect after listening you'll probably start running too for exercise or from some of the decisions you've spent your life. Making your work is so so incredibly impressive reaches such an incredible depth Charter's new territory and it's been an unbelievable clearly very passion driven career. You had so my first question for you is why are you doing this um. It's a good question um.I um you know. I started off being obsessed by a human evolution ever since I was a kid. I was really interested in human evolution and I spent much of my early career working on skulls and heads and why they are the way they are. And then I kind of got involved in public health and issues of health and disease kind of through the back door. I sort of slowly shifted my research trajectory towards studying the evolution of running and then the evolution of physical activity and its relationship to health and disease and and I've become part of a movement that's often known as evolutionary medicine which is how to apply evolutionary theory and data to issues of health and disease evolutionary medicine. I've never heard that term before. But I love it where has your work on evolutionary medicine. Let's call it where has that taken you where where has it taken you to learn to research to study you know so much of what we think about in terms of health and disease comes from a tiny fragment of the world's population almost entirely like 90 of all. The medical information comes from people from the United States Canada Europe and Australia. So in order to study how bodies really work and how our bodies evolve to be. You have to leave places like Boston where I live and go to places like Africa or Mexico or wherever to look at at other populations and look at how those populations are transitioning to to Lifestyles like mine and so we've been working in Kenya for the last 15 years or so and I've traveled some other parts of the world as well. India you know to kind of collect some data but uh but mostly in mostly in Africa after doing all of this work and after taking in all of this information how has it shifted your perspective on running exercise.More broadly. What have there been any sort of significant cognitive perception changes you know yeah um I actually had a I mean. It doesn't happen very often but I had kind of an epiphany moment um. When I was working in Mexico. We were collecting data on the tarahumaro very also famous for their long distance running and there was this elderly guy. He's about 70 something years old and he's famous for his distance running and I was asking him how he trained and I had asked this question of a whole bunch of other people and the translator I was working with was always struggling to ask that question because it turns out there's no word for training in in that language. The concept of training doesn't exist so so she was trying to explain to this guy. What my question was um and I could even a translator I could figure out just from his tone of voice. He was like why would anybody run if you didn't have to and I suddenly realized yeah of course exercise is a very weird thing right well if you're if you're a farmer and you're working super hard every day in the field without machines and whatever or if you're a hunter-gatherer and you're walking. You know you know five to ten miles a day and digging and throwing you know doing all kinds of hard work and you're barely getting enough enough food why on Earth would you go for a needless five mile run in the morning I mean it's crazy right the most viewed videos of yours in the most viewed moments in those videos address. One question do you have any idea what it might be no actually the biggest myths in exercise right. And I think you actually pointed out one there with the um. Insight you got in Mexico. The way we exercise going to gyms. Practicing is the natural or human but evidently it's it's a consequence of the privilege of our lives and the Comfort we have of not having to seek out our dinner every day what are some of the other biggest myths within exercise that um you've come across in writing. This book gosh. There are so many I had to actually limit limit it to ten. So I think um if you understand physical activity and exercise you also have to understand inactivity and I think one of the biggest myths out.There is that you need eight hours of sleep a night and that sitting is when you're smoking you know that basically and I if you think about those two different myths. Why is it that we're constantly told to sleep more and to sit less actually. It seems a little contradictory to me right and it turns out that um that let's take sitting first so um you know. There are all these uh you know these slogans like sitting against and you're smoking and it's really bad for you and you know every time you sit in your chair. You lose two hours of your life and whatever uh turns out that uh all animals sit right. My dog sits um cows. Sit chickens sit every animal sits and hunter gatherers also sit in fact if you some of my students actually put sensors on hunter-gatherers and uh when we're doing some research in Farmers as well but they sit just as much as westerners um uh. So sitting is there's nothing special about being uh about today's life. It's sitting so it's that we sit all day long and don't do anything when we're not sitting right so if you and and furthermore the big distance difference is not so much how much we said but how how we sit so turns out that people who um if you get up every once in a while right. Interrupted sitting is actually much more healthy than non-interrupted sitting okay the same amount of time. So in other words. Two people might in the west people sit for an average about 40 minutes at about whereas hunter-gatherers for example are farmers in Africa where we work get up every about 10-15 minutes and when you do that you actually it's like turning on the engine of your car. You don't drive it around the block you're you're you're you're um you're turning on all kinds of cellular mechanisms. You lower blood sugar levels. Your. All kinds of genes get activated and it turns out that that is by far the most important way to way to sit so just get up every once in a while. Just pee frequently make a cup of tea. You know pet your dog whatever thinking when I'm on planes and I've got a long flight. I always sit in the aisle right.So I can get up a lot always and um what about sleep then so sleep is another interesting one so this idea that you know um that you need eight hours of sleep. It's been around for a long time. It's been around basically since the Industrial Revolution um but um if you actually so so colleagues in my field. So an evolutionary medicine have put sensors on people who don't have all the things that we're told have destroyed sleep so think about it. We're told that TV and lights and and uh you know our phones and all these things are are preventing us from sleeping. You know Edison destroyed sleep right uh so so when you put sensors on people who don't have any electricity and they don't have TVs and they don't have phones and they don't have have any of these gadgetry right electricity. They it turns out they sleep like six to seven hours a night um and um they uh and they don't nap um so this idea that natural human beings sleep eight hours. A night is just. It's just nonsense. It's just not true and furthermore when you start looking at the data seven hours if you actually look at if you graph sort of how many hours a night you sleep on the x-axis and sort of uh. You know some outcome like cardiovascular disease or just. How likely you are to die. It's kind of a U-shaped curve. So people don't get much sleep are in trouble but the bottom of that curve is pretty much always about seven hours so people actually do better if they sleep seven hours rather than eight hours and yet we're told that if you don't sleep eight hours there's something wrong right oh so you can oversleep well. Yeah. I mean there's also some complexity of this too because of course people who are ill might be sleeping more and so there's some there's some biases that creep into the how you analyze the data but but basically it turns out that seven is for most people optimal. But there's a lot of variation right you know teenagers sleep more older people sleep less.It's complicated one of the things popular in culture as well is this idea of doing 10 000 steps a day yeah. Now that's fun you know that started because of a Japanese epidemic pedometer um so but right before the the Olympics were in Tokyo. In the in the 60s they had invented the pedometer and they were in the sitting in a board room and they were discussing what to call the pedometer and they picked out of just out of the blue. They picked 10 000 steps because that's apparently an auspicious number and it sounded about right. There was no science behind it. Interestingly it turns out. It's pretty good um if you actually if you look at steps per day and health outcomes your average hunter-gatherer walks. Between 10 to 18 000 steps depends on male or female Etc and and if you look at steps per day and and outcomes um but around seven to eight thousand steps. The curve kind of bottoms out right. There's. It doesn't seem to be a huge advantage to taking more than that per day. In terms of you know large epidemiological studies so it turns out to be not that bad a goal. But it's not a there's no. It's not a perfect number like a lot of things right. It's just a kind of a it's a reasonable.

11:36 It's a reasonable goal to shoot for when you um when you started writing this. This book about exercise and running on all these subject matters was there any instant changes or any real lasting changes that you implemented into your own life from everything you've learned. I think about that all the time with this podcast I'll have a guest on I have these mini Eureka moments and then something will stick so. I'm wondering having studied all of these people all around the world and looked at their bodies and exercise and physical exertion. What have you taken into your own life that has stuck I would say that I've become more serious about doing some strength training. You know I've always loved walking and running and you know endurance kinds of activities and I've always sort of hated doing weights. You know I just don't like it and I'm I'm a wimp. You know. I'm not a very well.I'm not a very strong person and you know people tend to do what they like right you get reinforcement from it and the more I study the importance of resistance training and the more I study the importance of doing weights especially as you age um. The more I've the more I started kicking myself for for being uh being lazy about that so now I try to do a good two strength workouts out of every week at least and uh and take it more seriously because especially as you age loss of muscle mass can be really debilitating. There's a um the technical term for that is sarcopenia Sarco is is the Greek word for muscle and penia is loss of muscle loss. So as people get older they tend to lose muscle and when you do that you become frail and you lose functional capacity and then that starts off a vicious cycle right once that happens then you'll be less likely to be fiscally active and then of course. When you're less. Physically Active your muscles begin to waste away more and it's very debilitating and so I think as we get older and I'm getting older. It's more and more important you know to to kind of incorporate that so I think that's the one thing that I've I've taken to Heart yeah from what you said there. It sounds like not doing resistance training not doing not lifting weights as you age almost accelerates. Aging in any sort of superficial sense but but it also in a physiological sense. You're you're increasing the speed of Aging yeah. I'm not sure if I'd think about it that way. But it I think I I kind of reverse it slightly which is that you know aging is just the clock ticking on right. There's nothing we can do about age but senescence is the way the way our bodies degrade as we get older and what physical activity does affection. Maybe the most important thing about physical activity is that it slows senescence especially for certain organs and systems and there are different kinds of physical activities so there's endurance physical activities. You know like running walking Etc. Swimming and then strength or resistance physical activities and they have different kinds of ways in which they slow various properties of senescence which we you know colloquially call aging and all of them are important and I think one of the things that's really interesting about humans. In fact I think it may be the most important thing about this book and you asked about myths earlier. The most important myth I think by far is this idea that as you get older it's normal to be less active and that is just not true.We evolved to be grandparents. We evolved to live one of the things that's most interesting about humans. Maybe is that we evolve to live about 20 years or so after we stop reproducing. No other animal does that except except orcas maybe killer whales but with the exception of killer whales. Humans have this really weird life history. We evolve to be grandparents but grandparents in the old days weren't you know retiring to Florida. Or I don't know where they do. But they do in England or whatever go to Majorca or whatever and you know kick up their heels and play golf or whatever with carts. Grandparents in the in the olden days right or in many cultures still today are working right. They're working in the fields they're hunting they're. Gathering they're getting food for their children and their grandchildren. They're helping with child care and that physical activity is you know that's what their job is to be physically active. But in turn that physical activity turns on an amazing Suite of of physiological processes that counter aging turns on repair and maintenance processes that not only keep our muscles strong but also keep our DNA from accruing mutations keep our mitochondria numbers. High keep keep our the cells in our brain from accumulating Gunk so that prevents Alzheimer's and other forms of dementia I mean for almost for every system of the body. Physical activity has has benefits that slow the aging process and so when you stop doing it you accelerate and that's the way in which you it perceive. You perceive it as accelerating aging but really it's the absence of physical activity which lets aging run a mark in your first book. In 2013 the story of the human body in chapter 12 you said um use this phrase you use it or lose it. Basically. We we evolve to use or lose our bodies and I was sat with um someone recently and I was trying to figure out why it appears that when people retire or the other instance I've seen is when they're their elderly partner passes away. It appears as if they don't live much longer yeah. It's kind of like kind of folklore or something that once you retire your days are kind of numbered yeah yeah and I I was trying to figure out the evolutionary reason for that but it sounds like that's kind of what you've explained there.Well I mean I think part of that is um is depression right um when you lose a partner. I mean grief and depression your cortisol levels go up your immune system goes down. I mean you know. It's. It's really tough on your body. I mean psychosocial stress plays a serious physiological toll but but also as you just pointed out. When people retire. They're become less active and that that loss of activity has enormous effects. On every aspect of our of our of our body. I mean in our brain and our minds. I mean physical activity is important not just for physical health but also vital for mental health and I think a lot of the problems that a lot of mental health issues we have today depression anxiety uh some of them to some extent. We can attribute that to loss to less physical activity and as people age becoming less. Physically Active again makes them much more vulnerable to a wide. Suite of diseases so would you say we shouldn't retire well or if you do retire. I mean retiring is again another modern weird thing right nobody retired in the past I mean if you're a farmer. It's like a subsistence farmer and name it any place right. It's not like something you hit 65 and all of a sudden you no longer have to work in the fields. You work in the. Fields until you're you know until you're dead. Right and hunter-gatherers don't retire they. They continue to be physically active until until they die right or until they get too sick. So it's a very modern Western concept um and um and yes we do pay a price for it. But you of course can replace you know work that you do with with with challenging rewarding fun things to do.The important thing is just not to not to stop being Physically. Active one of my favorite studies ever published without a doubt um is a is a study done by a guy named Ralph paffenbarger. He realized that places like Harvard are fantastic for studying aging because um Harvard like other private universities never lets go of their alumni so until you the day you die. They're asking you for money on a regular basis and and so they're um um and so he he got the Alumni Association. The Harvard development office to let him follow a series of Harvard alumni from several years and can keep asking them and questions about their physical activity levels and also their diet and whether they smoked and stuff like that and then you track them for 25 30 years and what he found was that the alumni we have to correct it for every Factor you could think of that as you as the alumni got older. The effect of physical activity on their health outcomes was bigger and bigger so alumni who are in their 20s. 30s and 40s. For example who were exercising you know four or five times a week. They had about 20 percent lower death rates. By the time they got to their 60s and 70s. The alumni who were exercising more had 50 lower death rates so as you get older so what and this has been replicated again many times. But what he showed was that as you get older exercise becomes more not less important for maintaining your health been thinking a lot about this because I was saying to Jack. My dad is 60-ish but he's very very out of shape very very out of shape and I was in um. I was in Indonesia and I was with my girlfriend and we went and we were going white water rafting. So we had to go down this really big hill. With all these stairs. It was like 300 meters of stairs and I remember just thinking my dad wouldn't be able to do this at his age at 60 and I want to be able to go down those stairs when I'm his age because at the bottom there was a fun activity with someone I loved and to think that I'll get to a point in my life where not so far away in the grand scheme of things um where I won't be able to go up or down. Some stairs because I'm 60 um because of my sort of genetic predisposition.As I saw it was quite was quite sad but having heard you say that it really feels much more like a choice than it is genetics. Yeah look we have this expression in my field which is that genes load the gun. An environment pulls the trigger right. Some of us have genetic predispositions towards being you know more likely to get diabetes or heart disease or this or that or the other but our great great grandparents in different environments weren't getting these diseases or they were getting them at much much lower frequencies. It's not because they were dying earlier. It's because these diseases were less common. So I think we too often blame our genes for many of these. These these diseases um or many of these health problems um and it's I'm not in any way denying the role of genetics. But that environment is way more important and we have control over our environment to some extent and so if you want to reduce your risk of cardiovascular disease reduce your risk of diabetes reduce your risk of Alzheimer's dementia exercises in a Magic Bullet. It's not going to prevent you from getting those diseases completely. But it lowers your risk quite quite quite substantially and we know why too. I mean we have an immense amount of data on why that's the case for every single. One of these diseases we understand the mechanisms by which physical activity has uh. You know important mechanistic effects on on these diseases. So it's this epidemiological data. There's mechanistic data there's personal data. The problem is that it's hard to do right. It's. It takes willpower to overcome the the the inertia of of of of doing what's completely normal which is wanting to take it easy.

22:11 Right. I was I was just you know I just flew yesterday from Denver to Boston and in the in the in the in the airport you know. There are these escalators right next to the stairway right and and and and and um the escalator and the stair. It wasn't a huge stairway everybody's lining up to take the escalator and like the stairs are totally free. So I being me I of course. I can't. I'm not allowed to take the escalator unless you know I have to right so I run up the stairs. But you know it's but those people taking the escalator there's nothing wrong with them they're not lazy. It's just an instinct or it's an instinct to take to take it easy when you can right because and we now live in a world where everybody can do that right because we have escalators and and lifts and cars and shopping carts and all these wonderful devices to make our lives easier and now you have to overcome this fundamental Basic Instinct to take it easy in order to be physically active. And that's basically what exercise is and so and furthermore if you're out of if you're unfit and you're not really you know exercising. Isn't any fun right. It's it's. It's it's unpleasant. You you know you sweat and you get hot and you get cranky and you know um and and it's not that rewarding uh until you get fit and so uh people hate it right um and uh and then we blame them for being lazy. But they're actually just being they're just being normal and I think we need to have more compassion towards towards people who struggle to exercise quick one before we get back to this episode just give me 30 seconds of your time. Two things I wanted to say the first thing is a huge thank you for listening and tuning in to the show week after week means the world to all of us and this really is a dream that we absolutely never had and couldn't have imagined getting to this place. But secondly it's a dream where we feel like we're only just getting started and if you enjoy what we do here please join the 24 of people who watch this channel regularly and have hit that subscribe button means more than I can say and if you hit that subscribe button here's a promise I'm gonna make to you. I'm gonna do everything in my power to make this show as good as I can now and into the future. We're going to deliver the guests that you want me to speak to and we're going to continue to keep doing all of the things you love about. The show thank you thank you so much back to the episode. This Basic Instinct to take it easy are we evolved to be lazy take escalated Riders well. I wouldn't use the word lazy but we are evolved to take it easy to to rest whenever possible right.So we've now got ourselves into a bit of a comfort crisis here because everything has in our lives is optimizing us for convenience and ease right right and well. It's also it's it sells right. I mean Comfort. I mean I mean who prefers to sit in economy as opposed to business class right. Nobody. Right Comfort is nice right who prefers shoes that are uncomfortable right. We we you know comforts comforts you know we love Comfort right but since when is Comfort necessarily better for you right. I mean our comfortable shoes actually better for you than going Barefoot or the comfortable chair is better for you than we're taking the the lift better for you than taking this. It is a short term or at least it appears to be today right yes because we often value the short-term benefit over the long-term cost right um. That's hyperbolic discounting is the technical term for that but but um so we you know we live in a world where where we we you know we pay extra for for Comfort or and we'll prefer it but um but now we also live in a world where we have to now go out of our way to be physically active because it's no longer necessary and so again I go back to my original statement which is that people evolved to be physically active for two reasons and two reasons only when it's necessarily rewarding. When we don't make it necessary. We need to figure out ways to make it rewarding and and that's hard it's very hard making it rewarding. So one way that you might make something rewarding is by looking at the stick and then the other side is maybe the carrot but just looking at the stick.Then you were going through a series of diseases a second ago. Alzheimer's um high blood pressure all of these kinds of things. Cardiovascular diseases I almost think we've come to assume that these are inevitabilities of Life yeah. We'll get cancer yeah. One of us will get yeah someone in here is going to get Alzheimer's and that's the way we live. So we're we're preparing to meditate when that day comes. That's right I get good forbid diagnosed with something. That's absolutely right in fact. That's what medical students today are taught right. If you go to medical school today. You're taught that as people get older their blood pressure goes up. I can tell you that's just not true. It's in the western world where people are physically inactive and eat. Crap diets that their blood pressure tends to go up but there are plenty of people. I'm actually one of them right who don't have high blood pressure as they age and guess. What's the best way to prevent getting a high blood pressure. As you age. It's um you know. It's not like a broken record. But we have this idea that as you get older yes you're are gonna you're and we're lucky right you know because we don't die from smallpox when we're 30. We're lucky to get cancer when we're 60 right. What we've done is. We've confused diseases that are more common with aging with age being a cause of those diseases in the first place and they're not inevitable inevitable diseases and many of them are preventable and and the problem is that in our society we we don't value prevention. Very much we may talk about it but we don't really put our money where our mouth is right in the U.S which is arguably one of the worst Healthcare Systems. It is the worst Healthcare System. Among the industrialized Western World. We spend approximately three percent of our budget our medical Budget on prevention. And yet when people walk into a doctor's office 75 of the time the disease is according to the Center for Disease Control of preventable disease. So we essentially spend nothing to prevent diseases that overwhelm our system and cause enormous amounts of misery. It's a completely backwards due stupid system and so and and the good news is. It's not that hard to prevent a lot of these things um. It takes willpower and takes education and it takes access to to good quality food and whatever um but um so in the one sense. It's very depressing on the other hand. The Optimist in me says you know we really can do something and people even if without even if they're not wealthy or whatever I mean. They're simple things that everybody can do to improve their health outcomes.These diseases we we encountered today as we age and just generally in our society when you look at hunter gatherer hunter-gatherer communities where you look at certain tribes around the world. Maybe in Africa do you see the same um the same types of diseases in the same um occurrence level of occurrence or is there some diseases which just don't like I'm wondering if like if because you know cancer seems to be so popular for as the disease and Alzheimer's and these kinds of things. So I Wonder has that always been the case throughout human history and is that the case in other parts of the world that's such a good question. So first of all some of these. Some of these diseases are really hard to to measure in non-western populations because we don't have the diagnostic tools so nobody really knows how common cancer is in in a lot of parts of the world right. There's just the data don't exist that said when you make estimates and you do look at the studies that are out there and even if you look in in historical records and in places like Europe where people have been keeping track of this. There is no question that cancer rates have been rising and that cancer rates are much much more common in the western world. There's a strong association between Cancer and wealth and that's because cancer is basically a disease of energy right when your cells because cancer is basically natural selection gone awry in the body. It's when cells start competing with each other either in ways that that cause basically and start you know going you know multiplying and dividing out of control right. It's a kind of natural selection and what is it that those cells are doing they're competing for energy and when you have more energy like when you're eating more and being less. Physically Active you can you basically feed those cells so um so cancer so a high levels of insulin insulin is highly uh related to cancer. High insulin levels are carcinogenic um high levels of a body of energy. You cause women for example to increase the the amount of estrogen and progesterone that they produce men produce more testosterone. These are and these are these are hormones that of course are for good for reproduction but they're but again we have we evolve to be to have as many babies as possible. Right but that doesn't mean that translates into Health right so more estrogen more progesterone increases risks of say breast cancer or testosterone increases the risk of prostate cancer so if you look at most diseases. Right people are more physically active. They have lower levels of estrogen progesterone testosterone. They have lower levels of insulin. They have lower levels of blood sugar.All of these depressed cancer rates and on average people who are Physically Active have much lower rates of almost every single kind of cancer that you can think of women who walk 150. You know get 150 minutes of physical activity. A week have on average about 30 to 50 lower lifetime breast cancer risks than people who are sedentary and yet for some reason. This is not a well-known fact um and we underst we have we have epidemiological data. We have mechanistic data. We understand how and why it works and yet and that how often do you hear about cancer prevention. We talk about treating cancer which is all important. If I get cancer I would like it treated too thank you very much but why don't we spend more energy and activity and and have more education about how to prevent cancers in the first place physical act. I don't mean I've never had that before so that's that's really helped me um to add more value to exercise in my mind. You're talking there about insulin levels and how that has there's a link between your insulin levels and your chances of getting cancer sugar glucose inflammation bad yeah I mean I mean look if you want to if you want to take like the three things you should you know if you really care about your health. Don't smoke right that's kind of obvious I think everybody knows that get some exercise. I don't think you need me to tell you that right and and cut down on sugar and foods that are high in sugar and low in fiber right that you know what we call high glycemic foods. Those are the foods that elevate your your your your blood glucose levels.Your your insulin levels shoot up and Insulin insulin. The basic function of insulin is is it's what we call an anabolic hormone. It's its job is to is to store energy glucose glucose but also fat okay all right okay so what insulin does is to get energy into cells. So it's like a taxi. It's like an Uber. It's like a taxi yeah well. I mean it. It's not attack. It's like a it's telling other cells to do that so insulin for example binds to other cells that are the actual taxis. So it's like. It's like calling the Uber I would I can maybe right um and um and insulin is is you know. It's the fundam so when you when you eat food. Insulin levels go up because its job is to store that energy and when you exercise insulin levels go down because because you want to then use that energy right so so uh so when cells get more energy. They're more prone to going out of control basically and and and and inflammation is caused by basically by getting you store so much fat in your cells that those fat cells start to swell and when those starts to swell like anything right they start to rupture. They get damaged and that damage attracts the immune system and the immune system gets turned on and that causes inflammation so so too much adiposity. Too much fats you know over swollen fat cells is the is a primary cause of systemic inflammation and inflammation is like the slow burn in our bodies that causes widespread damage to pretty much everything you can think of and it turns out that so the two ways to deal with inflammation are one to prevent it right. So don't eat foods that are pro-inflammatory like anything with a lot of sugar basically right. I mean that you know the sugar is highly inflammatory. Um or trans. Fats are highly inflammatory but also turns out. Many people don't know this but you also want to turn down your immune system. Right you want to turn the dial down and I don't know just give you one guess what it is that does that exercise exercise and the and and the way it does. That is that when you when you're physically active you're using your muscle cells. It turns out. Muscles are also an endocrine organ. Your muscles are producing a molecule called interleukin-6 il-6 that in low levels is pro-inflammatory but at high levels it's actually anti-inflammatory. It turns down inflammation and your muscles because a third of your body is muscle right when you go for a run or or swim or bike ride or whatever you're producing a ton of this stuff and it turns down levels of information. So people are Physically Active. Even if they're overweight are actually controlling and regulating their inflammation. We never evolved to regulate inflammation because in this way because we never evolved to be physically inactive until recently nobody was physically inactive until unless they were dying right so. So so we never evolved an alternative mechanism to regulator inflammation other than physical activity and we didn't live in a world.

35:18 With this much sugar. We never lived in a way I mean it's astonishing you pay more money for Foods today that have less sugar added right. I mean that's just ridiculous right because it's so cheap and sugar is you know we love. Everybody loves sugar I mean I've um I've gone hunting with um hunter-gatherers. You know you know foreign and um and I can tell you that they're honey addicts right. I mean I've gone out with these guys and they go from you know if they if they fail on their hunt like by 10 or 11. If you haven't killed an animal. You know that's it for the day right and then it comes. It turns from being a Hunting Expedition to a honey collecting Expedition and they'll go from hive to. Hive to Hive get smoke burn out the bees and just Gorge themselves on more honey than I could possibly imagine to eat. Except these are a lean. Physically Active hunter-gatherers and they they handle it just fine um.But it's you know. It's the it's the Paleolithic equivalent of you know eating Mars Bars all day long but they've been out doing physical activity for how long yeah I mean. The average day is about 15 kilometers of of walking with some running yeah. So so so they're you know they can. They can they can cope with it how many hours is that oh that's two to three hours probably okay. So from that I have garnered that I need to do 15 kilometers a day for two or three hours every day well remember. It's not a prescription right so that's a kind of like the Paleo fantasy sort of naturalistic fantasy that if you live like a hunter-gatherer somehow your your world will be perfect right. That's basically what the paleo diet is sort of all about right and that's not true either yes. We need to be physically active but it turns out that a certain amount you know if you're any any physical activity is better than none right and if you look at the kind of any curve of any output. Any health health outcome like how many years you live or whether you're likely to get cancer or heart disease or whatever you know any little physical activity. Your curve starts to fall quickly right your likelihood of cardiovascular disease. That's just you know a few minutes a day of exercise has big benefits but eventually that curve flattens out right and it flattens out well before the hunter-gatherer level. So you don't need to be a hunter-gatherer in terms of physical activity to get the benefits.This is a I've asked a few people. This question I don't think everyone's anyone's really answered it um. But I suspect you might be able to if if you were responsible for redesigning the nature of our modern world to make it more matched and less mismatched. What are some of the first things you would do to help Society benefit in terms of our happiness and our health. I I think about this all the time because we don't seem to be turning around. We seem to be hurtling in a direction kind of unconsciously towards artificial intelligence and moving less and being more sedentary and taking pills more to fix everything lonelier than ever before you know. If we were to redesign it blank canvas piece of paper that's a tough question because um we've essentially given ourselves what we want right.I can go into a supermarket and I mean I can do something that's unimaginable until recently I can have I can have basically anything I can eat better than the king of France. You know a few Generations ago. I can I can I mean here. I can New York. There's like every Cuisine possibly available to me. I I don't ever have to climb the stairs I can take elevators. I mean we've we've we've. We've made our world so convenient and comfortable and yet there are consequences to the many of the things that we crave and want so in an Ideal World. You don't want to you don't want to REM. I mean you have to you have to honor and respect people's um um desires right. I'm not a I don't believe in in preventing people from taking the elevator right or or forcing them to you know eat eat a whole grain bread as opposed to white bread right. But if you banned white bread and you banned elevators other than for those people that need it for accessibility reasons Etc. They would do better over the long term they would be healthy and happier they would right so. It's really a balancing act between between um um respecting people's Liberties and choices and educating them and helping them so in my world. I would I would do more to nudge people right um. I would instead of banning sugar. I would tax it more um instead of um pushing uh all kinds of foods on people. I would push.I mean why don't we why don't we advertise healthy foods the way we advertise. Unhealthy. Foods right I mean when's the last time you saw an ad for just how amazingly healthy asparagus was right but that doesn't get the part of my brain going does it. No. It doesn't but um but we could do more to to nudge and encourage and help people right. You don't have to like ban sugar and cookies right otherwise some people but but but simply promote um and help people help themselves right. Most people want to eat healthier food. Most people want to exercise um but they live in a world where it's hard to do it and they live in a world where um there are very few incentives. I would make it such that healthy food would be as as inexpensive as as unhealthy food and make sure that that people had incentives and and make it also fun to be physically active. Like for example um. Every I mean who doesn't like to dance right. Every culture in the world has dancing. Right dancing is a form of of physical activity. It's social. It's fun. It's engaging why don't. We have uh why doesn't every every town in America sponsor dancing right um. You know it would probably do an enormous amount for people's physical health and their mental health. I mean we could do that I mean that's just one example right.So I would I would um. I would I would I would and and why is it that in medical schools doctors don't learn about I mean they don't they don't study nutrition and they don't don't study exercise and they don't learn um because that's because in our medical system is designed to treat people after they get sick rather than prevent people from getting sick so so we need to you know reverse how we fund health care right and so schools of Public Health are these kind of little marginalized places where you know where where great ideas go to die right and and medical schools where all the money is right and doctors aren't. I mean their entire fields of medicine that don't have the word preventive associated with them. I mean you've ever heard of preventive Orthodontics or preventive. Uh you know Optometry or preventing you know the preventive Orthopedics I mean it just doesn't exist right so we we could do a lot more um and and have enormous benefits chapter. 11 of this book you talk about someone who has taken their own approach to getting people moving and exercising um in their own business.

42:29 That's the bjornberg company I love that Bjorn ball company can you tell me about that yeah. So I was um so I was. I was curious about this idea of how to get how to help people be more physically active right and again you know my my fundamental hypothesis is that we evolved to be physically active either when it's necessary or rewarding. And so I was curious if there's any any companies in the world that have made physical activity necessary. In other words what if we force people to be physically active and I found one so far. I think there's only one company in the world that I know of maybe there's some others. But this is the only one I've ever found so far. And it's the bjornborg sports company in Sweden where the CEO of the company is. This crazy sort of exercise addict and he um. He requires every member of the company to to exercise.They have sports hour every Friday at 11 o'clock. So I actually um when I when I was searching around and I was thinking you know I write working on the book I actually you know got. I found an article about them and I you know I clicked on the on the company website and you know how every most companies have a little contact. Us. So I I clicked on the contact desk and I wrote a little note saying you know dear bjornberg company. I'm a researcher. An evolutionary biologist I'm interested in exercise and I'm and I'm fascinated by how your company requires people to exercise. Can I learn more and the next morning there was a an email from the CEO of the company saying why don't you come and visit us. So so I hopped on a plane. A few a few months later went to Sweden and they they let me he was so nice. He just let me just go anywhere in the company and I went to sports Tower and I I talked to employees throughout the company and it was fascinating I mean um a lot of the employees of the company. First of all a bunch of people apparently left the company when he took over a CEO and required this but it doesn't matter who you are. You could be working in the mail room you could be the CEO. You could be a visiting board member whoever you are. If you're there.On Friday you have to go exercise with them and they have this pretty serious kind of exercise thing and apparently some people quit but um but but pretty. Much everybody else said you know it's actually a pretty damn. Good. Thing do you agree with that approach well yes and no um every University in the world used to require in every school. Right supposedly requires exercise right. I'm sure you had physical exercise. You know physical some kind of phys. Ed required in your school. Those standards are slipping around the world and more and more kids are doing less and less in school universities were no exception. It used to be that all universities required. Some degree of physical education. Mine was no exception in fact Harvard was a leader in that back in the you know 100 something years ago and over the uh since basically the 1970s that's basically disappeared although most students if you ask them they think yeah. It's actually a pretty good idea. So I don't know maybe. We can bring back exercise as a and and the thing is that if you get used to it right when you're young you're more likely to do it when you're older right because you set those are the that's the age in which your habits become become about. Your habits become your habits right and so at this a certain age where where if you can keep keep you know get that making it make it a habit you're probably more likely to continue doing it for the rest of your life. We kind of see it as overreach don't we I was thinking about if I was to announce one of my companies that everyone is now required to exercise it would seem like like tremendous overreach. If I announce that everyone is required to read a certain book. They do it. It'll be fine and it might be seen as a positive thing right. It might be a representation of our values that we are Learners and we're innovators and we keep you know nourishing our brains.But we turn around to your team and said this thing we're all acquired to you're all required to go for a run every day or something people would it just feels personal yeah like that's not the responsibility of an organization to tell me to go for exercise. But we have we have company you know. Retreats. I mean we do all kinds of stuff where people are required to do it. So I don't know I challenge. You try it what we do and what we've always done. We even do it with this team. The driver SEO team is about 30 people. So we have a fitness channel in the company. Um slack channel the communication channel that we use and in that channel um and we did this at my previous company as well where we would enable and facilitate. So we someone started a women's football team so we enabled it and promoted it. Someone started a men's football team so we enabled it and promoted it and this this also applies to non-physical sort of exercise. Related clubs. Like someone starts the reading club and we enabled it and promoted it um and we also paid for it if they need to if they need new kits for example when the women's football team needed wanted to have their own uniforms. We paid for it because we saw a huge value in terms of Staff retention connection community and all those things that actually lead up to staff retention. If we could have more Social Clubs outside of the office you know if you're thinking about leaving a job.There's a number of things you weigh up to pay the job whatever but you also weigh up how the community like the group of people I love and how much they bring to my life and I actually think in the remote. Working World um. It's something that CEOs and leaders have really not paid enough attention to that if they really want to retain their team members they should have them together as much as they can even outside of the office bonding in a world where screens are on. The rise and pubs are on the decline in social activities and churches are on the decline. There's less sort of Institutions that connect to socially work has a big opportunity to do to do that so one of my big things always in. My head is like how can I get the team members and my companies to hang out more and a multiplier to that is how can I get them to hang out more and move their bodies more because then they'll feel better right well well think about it. It's play right play yeah exactly and I mean and play is what is another thing we evolve to do right like kids play and we're one of the few species that plays as adults right and what is play play is a way in which you you learn cooperation. You you you build community but you also move your body right in the first chapter of your book.You say that you went to visit the Native American tribe and I'm going to try and pronounce this the Tara Huma Tara humara and they're famous for their long running. Yes. What did you learn about running from them well. It's you know they have been famous for well over 100 years. I mean many uh people have gone to study the taramara and have commented on their amazing ability to run. But what I really learned from them is that um for them. Physical activity is spiritual. Um. You know there's this book Born to Run that uh that describes their their running and calls them a hidden tribe of Supernatural super athletes. They're not hidden and they're not super athletes um and um and the one thing that the book missed was that the the main impetus for the for their for the running. They do these famous long-distance races is that it's a form of Prayer. It's really very beautiful um and um and it's a it's a metaphor for for life and um and and it's also a an opportunity to bet in sports and all that it's all wrapped into one and and what I've learned was that this actually used to be almost Universal among Native American populations. Right Native American tribes. Everybody had long distance races and ball games and and they were all had a spiritual element. It's just that they've they've retained their traditions because they're in a very remote part of of Mexico that's essentially inaccessible we all used to do. This. All humans used to do this and in fact if you think if you look around the world. Every population has this tradition of endurance during its events. Some of the subject might you talk about in your book but also outside of your book is is how we used to run um in terms of you know.

50:12 I was at the foot doctor what's it called. I don't know what they're called podiatrist. That's what I said but podiatrist. What did I say. But I went to the podiatrist the other day because I I got this. What's it called when you're I'm gonna point it on my foot. It's part of my foot here started to get lots of pain everything. That's it plantar officiitis. I started to get some plantar fasciitis and it was just this ongoing pain and they prescribed me. Some insoles I stood on a couple of machines some soft stuff and they measured my foot and took this scan of it and said right basically. You're standing wrong um. Your arch is a bit too flat take these insoles and wear them in all of your shoes and I just I always think in these moments when someone prescribes me something. That's not natural. I go why like where did I go wrong. And I think that's the key question where did I go wrong who lied to me to the point now that at 30 years old I have these bloody insoles that I have to put in all my shoes because presumably that's not natural presumably. My my ancestors don't have Bloody insoles yeah so plantar fasciitis is what I would call a mismatch disease right a disease that's more common or more severe because our bodies are inadequately adapted to Modern environments and in your case and as is the case with a lot of people you have a weak foot. So so we you know you look like you go to the gym looks like you're a pretty fit person right. I'll make a bet you you strengthen pretty much every muscle group in your body. Except your feet right. No come on right well but we don't right. One of the reasons is because we we encase our feet in stiff-sold shoes that are very comfortable and and the reason the shoes are comfortable is that your your foot muscles have to do less work. When you was using those shoes right. We have shoes that are stiff soles they have arch supports. Right and your foot has four layers of muscles in them and those muscles are supporting your arch and at the bottom of those four layers of muscles is this layer of connective tissue.The plantar fascia and the problem with the plantar fascia is that if it stretches too much it like anything else right it gets inflamed but it's got almost no vascularization right. So it's very hard for it to repair itself when it gets inflamed to prevent plaster plantar fasciitis. The best way to preventing it is having a strong foot a strong foot's a healthy foot so the way to the way to treat the disease on the long term is to strengthen your foot but if you want to just alleviate the symptoms. That's what your podiatrist did by giving you an insole right. It's basically preventing your muscle your arch from collapsing as much making it more comfortable. So your your plantar fascia gets stress less and so it can kind of alleviates that that that that that stretching and hence the pain right so that's a typical example of what I call dis Evolution. It's what what happens when you treat the symptoms of a mismatched disease rather than their causes of preventing their causes. So podiatrists are a bit like drug pushers in that sense right because they're they're essentially putting your foot in a cast right and then and for the rest of your life. You kind of have to keep using them unless you strengthen your feet. So I so so there's nothing wrong with those you know treating the symptoms. I mean pain is no fun so where are the insoles right to kind of you know alleviate the pain but also work on strengthening your foot and I think you'll find that the plantar fasciitis will will disappear and never come back so. The plantar fasciitis fasciitis um has now healed after about a month of wearing the insole um. I no longer have the insoles um with me here in New York and I don't have them in any of my shoes because I've also taken a bit of time off um running on my feet.I was playing a lot of football so now I'm at a point where I can go to the preventable stage prevent it happening again and you said to. Strengthen my foot how does one strengthen their foot good question. So there are some exercises and they're kind of foot doming exercises and things like that. They're you know I can send you some links to videos showing you some good foot strengthening exercises so that's one way to do it. But the other way is to wear more minimal shoes to wear shoes that aren't stiff sold that don't have arch supports go barefoot a lot right and those that will naturally strengthen the muscles in your foot because you'll have to use those muscles so you ever gone for like a long walk or run on a beach right and afterwards your your feet are kind of tired right. The reason your feet are tired is because you're now working on a compliant surface right. It's not stiff so your muscles having to work more to stiffen your foot to push you forward. Right jack could you go grab my the black shoe out of my bag. I just want to show him something so uh so wearing shoes that aren't as stiff sold when they don't have arch supports will slowly strengthen your feet but and this is a huge but if you do too much too fast you will your plantar fasciates will come roaring back and you'll hate me you'll like you'll never forgive me because um yeah there's a Vivo barefoots um yeah. I wear the same shoes oh you've got the same shoes on um great shoes yeah. Those are wonderful shoes. Those are those are the those are the exactly the kind of shoes that will help strengthen your feet. These are failing a new addition in my life yeah yeah. They and they feel really strange because you can kind of feel the floor yeah. It's exactly what you've described is yeah but but you you can transition if you have a weak feet which I'm guessing you do you if you go if you suddenly. If that's the only shoe you wear all the time you'll probably regret. It right so so slowly slowly slowly increase the percentage of time that just like anything else if you if you like suddenly decide to lift you know huge weights that you can't lift before you'll hurt yourself right. The same thing is with your feet so so slowly. It does it but you if you do it gradually and slowly and carefully you can build up strength in your foot and um and you'll and you'll be a happier happier person and this is this goes back to everything else. You've said about how choosing Comfort choosing to have a nice supportive shoe has actually just kind of deferred a problem off into the future for me. It's the same with diets the same with avoiding exercise and being sanitary and and all these other things where when you choose the easy Road in the short term which is this wonderful cushioned shoe I've chosen. The muscle hasn't built up in my foot and I've paid the price correct so I need to again choose discomfort more in the short term. Go up. The stairs run Barefoot to avoid the late the consequences later down the line yeah. I mean I don't think you have to run Barefoot but um though it can be fun but um um. But yeah I mean and I can think of plenty of other examples um we love Comfort but comfort's not necessarily good for us when you um.When you look at these tribes are they do you know who liver King is huge. Massive muscles talks about ancestral living um what do our hunter-gatherer ancestors look like in terms of them. Not like him. No okay I mean look think about it. Muscle is really expensive right. It's actually a super expensive tissue. About a third of our body is muscle and it's using up about about you know. A fifth or more of the calories that we're expending right uh just just sitting there. Not even using them right. They're they're very costly tissues right and so if you have more muscle than you need you're basically adding to your your cost of living right. If you're. If you're a hunter-gatherer or even a subsistence farmer living on the margin of food security having more muscle than you need is actually deleterious. Right remember the only thing that natural selection cares about is how many offspring you have we survive and reproduce. It doesn't care if you're strong or healthy or nice or loved or you know fun or whatever it only cares about whether you have grandchildren. That's it right. That's that's cold calculus of selection. My brain is going if I have big muscles. I'll have more romantic opportunities and then I'll have grandchildren well only up to a certain point right now so if more muscles if if they attract the opposite sex and and make them want to reproduce with you yes that could be a benefit. I'm not so sure how much women are attracted to the liver King but um and that's not something I even want to know the answer to but um and certainly shouldn't ask him but um um um.But but there's a reason we have use it or lose it which you mentioned earlier right because when we need when we increase our demand we increase our capacity right. When you go to the gym and you work out right you build muscle. But if you stop using those muscles you lose it and that's an adaptation right because you don't want to spend extra energy on muscles. You're not using right so you want enough but not too much. You want to be economical with muscle mass right um and so our if you look at the data from hunter-gatherers and people have done that they've done grip strength tests Etc and all kinds of other fun things with like mini Olympics. I mean we've done. This too um people are reasonably strong but they're not super strong and they're not. They're not buff and built and bulked and all that sort of stuff. They've got enough muscle to do what they need to do but no more and the reason why people find muscle attractive. Anyway is because it's evolutionary signal isn't it of uh reproductive value and resources. Maybe and the ability to go out and you know what I mean why why does why does a woman for example find a man with muscles or in good shape attractive in 2023 when we're not hunting for gazelle well. I'm not a I'm not a I'm not a psychologist or or so. I'm not sure if I'm qualified to answer that but I could I could Venture the guest that obviously if you're trying to if you know we pair bond as a species and we have been for for millions of years. Probably you want to pair bond with somebody who's going to because we also have of cooperation and food sharing right. You want to pair bond with somebody who's gonna be able to you know bring home the bacon literally and figuratively right but but bringing home. The bacon does not mean looking like Arnold Schwarzenegger at least back in the day Arnold Schwarzenegger back in the day right being bringing home the bacon back in the day meant being a persistence Hunter being able to run long distances and being moderately strong so they looked more like a marathoner or or a football player than they did a a weight lifter right so it's conceivable.It's conceivable that someone who is really really big is actually um less attractive because they wouldn't have been able to hunt and run and Hunt as well as someone who was a little bit. Yeah you also have to you have to feed my you have to feed them more too yeah and that's a you know. Those are precious calories. So I'm gonna guess that uh look if you look in in non-western populations uh you don't see physiques like that. This is a this is a privilege of people who are able to go to gyms and um and you know eat you know you know whey powder shakes and all that kind of stuff to kind of build their crazy muscle mass. But it's not something that our ancestors were able to do on a regular basis that's for sure a quick quote on huel as you know they're a sponsor of this podcast and I'm an investor in the company. One of the things I've never really explained is how I came to have a relationship with Hugh one day in the office. Many years ago a guy walked past called Michael and he was wearing a heeled t-shirt and I was really compelled by the logo I just thought from a design aesthetic point of view. It was really interesting and I asked him what that word meant and why he was wearing that T-shirt and he said it's this brand called heal and they make food that is nutritionally complete and very very convenient and has the planet in mind and he the next day dropped off a little bottle of fuel on my desk and from that day onwards I completely got it because I'm someone that cares tremendously about having a nutritionally complete diet but sometimes because of the way my life is that falls by the wayside. So if there was a really convenient reliable trustworthy way for me to be nutritionally complete in an affordable away. I was all ears especially if it's a way that is conscious of the planet. Give it a chance give it a shot.

01:01:45 Let me know what you think there's another myth that are you bust which I thought was really interesting because I think I know a lot of people that have used this as a reason not to run. They say it's really bad for your knees. Oh man that gets me so mad right. I mean I hear this from doctors. All the time right. Oh yeah writing is bad for your knees. Now it is true that knee injuries are the most common running injuries um but arthritis which is really what they're usually talking about. It's absolutely definitively not true that running increases rates of knee cartilage damage and arthritis. So arthritis is caused by cartilage wearing away in a joint right and it's a it's a myth that that running actually increases cartilage damage. If you have arthritis running is excruciating and problematic but if you don't have it running actually if anything may be slightly preventive because cartilage joints like everything else benefits from being used.Right and so physical activity actually helps promote strong and healthy joints. We used to think that it just caused them to wear away but actually you know like cars you know wearing away at their tires but now we know that actually physical activity promotes repair mechanisms and cartilage just as it does in other tissues in the body and um and of course. The other thing about running is that I think a lot of people run incorrectly today so uh so that's why we started studying barefoot running. Millions you know along a few. A bunch of few decades ago is because if humans have been running for millions of years most of that time we were running Barefoot so we're kind of curious how did people run before shoes and what we learned was that today shoes have these cushioned heels that enable you to essentially run the way you walk right. You land on your heel and everybody who's Barefoot sometimes lands on their heel. But people who are Barefoot often more often than not land on the ball of their foot and then let their heel down. It's called a forefoot strike or a midfoot strike and when you do that we worked out the biomechanics of that and published a paper on the cover of nature showing that when you do that you actually prevent your foot from crashing into the ground causing it. What's called an impact a collisional force you run lightly and gently so if you were to take your shoes off and run up Lexington Avenue. Here I guarantee you you would not be landing on your heels within a few steps. You'd start landing on the ball of your foot because it hurts less and so that's how we evolve to run.We've off to run in a cushion in a way that that doesn't involve you know he's slamming into the ground with every step and the and that that causes less Force around your knee um the trade-off though because nothing comes for free everything has trade-offs is that it's harder on your ankles. Your calf muscles and your Achilles have to do now a lot more work to let your heel down and so people who switch from heel. Striking to forefoot striking often have Achilles tendon problems. They get calf muscle problems. They don't do it properly. They'll get their foot muscles aren't strong enough. They'll get all kinds of foot problems right so you can't just suddenly become a Barefoot Runner and start forefoot striking. If you're gonna switch. You have to switch gradually and slowly and build up strength and learn to do it properly. Another thing people do is they tend to run like a ballerina high up on their toes that's really hard on your ankles and your calves. So you got to do it properly but if you but it can have enormous benefits and so and we know again if you run that way. There's puts much less force on your knees and again knees are where people get injured the most so I think a lot of knee injuries come from um from the way in which we run so would you recommend if you can to run more Barefoot especially if you have those kind of shoes we just discussed well. I think what matters is how you run. What's on your feet okay. So I would say a Barefoot style. How do I learn to run in a new way. Though well. I mean there's some tricks. So one of them is um first of all. I don't know how you run so so maybe. Maybe you already run just fine um. But a Barefoot style tends to be a high stride rate or high stride frequency so 90 strides per minute or 180 steps per minute. Roughly you know um 170 180 steps. A minute is about right um relatively short strides so you're not throwing your leg out and to me.The most important thing is not what we call over striding. You've asked any coach on the planet they'll say overstriding is bad over strings when you throw your leg out way in front of you and you land and that leg is a stiff leg so that a stiff leg means more Force right um and uh and um and it's harder on your knees um and so if you and so a good runner lands uh with their with their shank with their tibia vertical so their ankle is below their knee. When you do that pretty. Much everything will work out properly right um. It'll mean that you won't land hard on your heel. It'll mean that your your leg will be acting like an excellent spring. You won't produce a lot of braking Force um. It's a it's a it's I to me. I think the most important skill in running is not to over stride um and um so. I actually so don't worry about how you're going to hit the ground just worry about your overstride if you solve your overstride. You're more likely to run well.What do you think's um what's the best kind of sort of cardiovascular exercise for the promotion of good health because I've been doing some CrossFit stuff. I've been doing some hit workouts um I've been trying not to run because I've had a few injuries and try not to run as much because it seems to be a little bit more impact than if I'm bullshitting myself there. But um so I've been doing some like hit workouts every for 30 minutes a day when I leave here well you do it. You hit. It works every single day pretty. Much every day at the moment. We track it with a group of friends. We have there's 10 of us in a WhatsApp group whoever's last whoever does the least workouts every month is evicted and there's a raffle. So there's a raffle yesterday. On the first was it the first yesterday yeah for a new member and we do that every month and we've done it for three and a half years that's good I've been in there. I was the first ever member so I've been in there for three and a half years well.I think you know I mean the most the best exercise. The one you like doing but is that one that's like better you know like the you know I think you got to mix it up. There is no one perfect exercise right I mean I think what you do. It sounds actually pretty good right. You got a mixture of of of you know low slow intensity. Some some high intensity you want to have some strength training. You want to have some cardio. I mean we never evolved to do one thing and our bodies are too complex to benefit from just one thing. Uh mixing it up is is the obvious way to go right um. I think the Bedrock for any kind of physical. I mean you've asked anybody. Right cardio is the Bedrock of of of of of of of of exercise right it. It promotes the most health benefits right and it's good for your good. You know your burning energy. It's good for your cardiovascular system. It's good for controlling inflammation but but but there are different kinds of cardio in high intensity versus low intensity and there's also strength training right uh which is also you know important.

01:08:47 So you know there's no look. We've tried to medicalize exercise right. It's like a like. There's a proper dose right you know take this pill. This many milligrams this many times per week right exercise. It doesn't work that way there is no there is no optimal dose. Everybody's different. It depends on are you more worried about heart disease or Alzheimer's or diabetes or depression or you know are you previously injured are you fit are you unfit. There's it's impossible to prescribe exercise in this kind of medicalized way. It doesn't work a lot of people exercise because they believe it will help them to lose fat belly fat are the biggest debates on the planet. It has been a huge debate. Even on this podcast I've had multiple people come and say a whole range of things about weight loss and cardio and I'm kind of I don't know what to believe anymore well. Anybody wasn't confused doesn't understand what's going on right you know it's um. It's sad that it's such a debate um but um but that's how science works right so um as you know I wrote about that. In this book um part of the explanation for the debate is that again what dose are you analyzing and what population in what kind of context right so though pretty. Much every major Health Organization in the world recommends that you get 150 minutes per week of physical activity that's kind of like The Benchmark. That's what the you know the wh who the World Health Organization considers the the division between being sedentary versus active so and a lot of people are unfit and overweight and struggling to be physically active have struggled to get 150 minutes a week right. So a lot of studies prescribe 150 minutes a week of exercise walking for example a moderate intensity physical activity and then look at its effects on weight loss and guess. What when you when you walk 150 minutes a week which is what 20 minutes a day of walking which is about a mile a mile a day. You're not going to lose much weight you're basically burning about 50 calories a day. Doing that right. That's a piddling amount of calories compared to drinking a glass of orange juice right. So so surprise surprise those kinds of studies show that those doses of physical activity are not very effective for weight loss. However plenty of rigorous controlled studies that look at higher doses of physical activity 300 minutes a week or more find that they are effective at losing for helping people lose weight but not fast and not large quantities. So you're never going to lose a lot of weight really fast by exercising it's not. Going to happen because you know a cheeseburger has what you know 800 900 calories. You have to run you know 15 kilometers to lose that to burn the same number of calories you're going to be hungry afterwards too. So you're going to make some of that back you have compensation so so physical activity is a is actually there's just no way around it. You have to be a flat earther not to argue this way. But they're you know their physical activity can help you lose weight. But it's not going to help. You lose a lot of weight fast and not at the low doses that often are prescribed. But the one thing that we do agree on. And I think this would not be controversial is that physical activity is really important for helping people prevent themselves from gaining weight or after a diet from regaining weight and there are many many studies which show this one of my favorite was a study that was done in Boston. On policemen. You know policemen are kind of a reputation for you know having too many donuts and being overweight right and Boston is no exception. So they did this great study at Boston University right across across the river where they got a bunch of policemen on a diet. A really severe diet. The policemen all lost weight but some of the policemen were had to diet and exercise. Some just dieted alone and as you might imagine the ones who died plus exercise lost a little bit more weight not a lot just a little but and then they tracked them for months afterwards because most people after a diet. The weight comes just crashing back right. The policeman who's kept exercising even after the diet was over and they went back to eating whatever the hell. They wanted donuts whatever they're the ones who kept the weight off but the ones who didn't exercise the way it came crashing back.Another good example would be the have you ever seen the TV show The Biggest Loser. Uh yes were they are people going to lose weight yeah so that so there's a crazy show right these people you know this is like totally unhealthy. They were confined to a Ranch in Malibu and he's got these people lost ridiculous amounts of weight. A guy named um Kevin Hall at the National Institute of Health studied them from for for years afterwards and looked at and most of them regained a lot of the weight that they lost and there was one person on the show who did not and that was the person who kept exercising right and that's you know just yet more. We said one data point but there's lots and lots of evidence to show that physical activity what its other important benefit when it comes to weight is is preventing weight gain or weight regain. When we talk about dieting. We talk about exercise or Diet exercise or Diet like why is it an or I mean why isn't it exercise and diet. Diet is of course the Bedrock for weight loss. But exercise also plays an important role and should be part of the mix. On the um police example and The Biggest Loser example I can relate in the sense that when I exercise when I go through the moments of my life where I'm most committed to exercise. I'm also most committed to my diet yeah because I if I go to the gym I will not then leave the gym and have a donut or a pizza absolutely. Not. It seems like wasting the effort. So if you look at the sort of correlation between the moments in my life where I eat healthiest. They're also the moments in my life where I'm most most focused on the gym and I noticed there was a couple of months ago. I had a bit of a motivation slump managed to stay in a little WhatsApp group but coaster down the bottom of the leaderboard for a couple of months on a just like surviving every month by one um and through those moments. My motivation of the gym had gone down and my diet had gone down the minute I managed to get in the gym and do a big workout. The same day. My diet came back yeah of course right and they co-vary right and and that's one of the reasons why when people do big studies of of you know what you know you can look at what what people die of right what's on the death certificate you know cancer heart disease whatever heart attack um and then you look at what caused the cancer. What caused heart disease when people try to do that. It's almost impossible to separate diet and exercise because people who tend to eat better also tend to exercise more. They're both in our modern upside down topsy-turvy world. They're both markers of privilege. People have money to go to the gym almost have money to buy healthy foods and um and people who care about their physical activity also tend to care about their diet so so at that level. They're very hard to separate. However if you're studying a particular component of a system and it randomized controls trial in a lab you can separate them out and so we know that they have independent and also interact of effects. What is the um the most important thing we haven't talked about Daniel. I think the most important thing is that we need to be compassionate towards each other. I mean there's so much shaming and blaming and prescriptions and you know you know the reason I entitled. The book exercised is that people we make people feel exercised about exercise. We make them feel uncomfortable and I'm confident and shamed and and you know here you and I are having this conversation. But I can tell that you you take you know you're you're I mean I know I've listened to enough of your podcast. You care about your your health and your care about diet. You care about exercise and people may look at you and think gosh.I wish I was like him but uh it's just not me you know I can't I'm not. I'm not there right and they may feel put off by our conversation. And I think that so often these discussions make people feel feel bad about about what they're doing and I and I and I and I and I think that what we need to emphasize is that if you put you know if you put a chocolate cake and an apple in front of me. Here I would want to eat the chocolate cake and it would. I might eat the apple only because you're there. But if you weren't there I would eat the chocolate cake right and and when I'm in the in the in my building at Harvard. My office is on the fifth floor of this old Victorian building. Every single day I want to take the elevator and the only reason I take the stairs is that if anybody catches me in the elevator I'll be a hypocrite. It's not that I don't want to take the elevator I do want to take the elevator right. I guess you guys say Lift right um and and we make people feel bad for taking the elevator right um they should feel bad. It's an instinct and so I think we have to figure out ways to help people without shaming them and without blaming them and without bragging and whatever make you know you know talking about you know the marathon they ran or this that or the other make them feel um less uncomfortable about the topic and realize that you don't have to spend the English Channel or run. A marathon or you know join your WhatsApp group and do crazy hit workouts every day. By the way you don't need to hit workouts. Every day get the benefit um um instead just you know taking the stairs in your building. Every day anything is better than nothing and and you'll get benefits from that and I hope that that's the message that needs to get out right anything is better than nothing and if you can get started on that on that on that pathway. Then it'll it'll eventually become self-rewarding and and that and that leads me to the other topic that we didn't talk about which is that the reward system of physical activity you know you. And I if we go for like I'm really looking forward to my run tomorrow morning in the park I love running Central Park. It's one of the best places in the world around right a fantastic view from the top and it's just gorgeous right um. But when I run Central Park tomorrow I'm going to get a big dopamine hit. I'm gonna my body's gonna produce all this dopamine which is the molecule that says do that again right. It's a award gamblers get dopamine hits right people eat chocolate cake get a dopamine hit right but if I were unfit and overweight I wouldn't get that dopamine hit and so when people start exercising they don't get the reward that people who are fit and and custom to doing it get and then they're made to feel bad like you didn't enjoy your run around Central Park well. It takes months if not years before you actually get that reward really yeah because because just like being overweight causes you to become insensitive. To insulin you become insensitive to all kinds of other hormones. In neurotransmitters and dopamine is one of them so so. It's not an instant like benefit right. It's hard and so we need to be compassionate again towards people who are struggling to become fit and struggling to get the reward and also if you're overweight and you run around Central Park. It's like. If I were carrying weights and running around Central Park it'd be much harder right.Now. It's you know it's challenging and so we once you get you know into that state. It's hard to get back to the state of activity and so we we need as a as a society to to to help those folks rather than judge them. Those folks that are struggling and I was one of those folks that were struggling for many many years I was would say to myself every year um pretty much all of my adult life that this was going to be the year that I'd get fit. I try all of these various different you know fad exercise things by all this stuff I announced in 2017 that I was going to work out every single day and that lasted for six months and then I yo-yo back out of that. It never stuck with me until 2020 and that's I've been exercising six days a week. Since 2020. 82 percent of days and um I reflect and try and diagnose how I went from someone who what was it that changed and if I can figure out what it was that changed that the most fundamental level in my mindset or my attitude or my life or whatever it was. Then I can help other people figure out that too or at least give them more sound advice or at least be more empathetic. Whatever's required to help them you know and I have a platform here where I speak about exercise a lot on these things. So what's your suspicion. What's your suspicion on what it is that makes people go from being. You know maybe having a um a negative opinion towards exercise or their ability to be disciplined with it to becoming an exerciser. Do you know. I've this is a question that obsesses me in fact we have a big project right now a big Grant to actually study this oh really right now um because I the more I study it. The more I think it's social. The more I think that um um again. I think people are physically active in our modern world exercise for two reasons when it's necessary or rewarding and what makes it rewarding for most people is the social aspect and that social aspect can take many dimensions. It can be running with a group of friends and you know you might want to go only a mile but your friends convince you to run another Mile right and you end up running two miles right or you're feeling bad and crappy and your. You know your friends help you do it or I'm a running buddy right. And I often you know meet meet friends for early morning runs and I can tell you that the evening before it seems like a great idea to meet Aaron at 6am on the corner of Mass Ave and linnaean. The next morning at 6am I want to stay in bed with my wife. You know I don't want to. I want to meet this nasty. Smelly guy you know at 6am and the cold dark. But I agreed to meet him and out I go right now. I'm usually glad. I did it afterwards or um you know we can go on. There are other social ways in which which but or dancing right I mean nobody thinks of dancing as exercise. But it's exercise right so that's one important social Dimension and the other one though is accountability um. I describe in the book. I'm there's a there's a friend of mine in San Francisco who's struggling to just to exercise so she signed up for a program with this company called stick.com. I don't know if you run across it where it's a commitment contract where you send like a thousand dollars to them and they keep it in their bank account. They probably invest it make a lot of money on it too. But you set up a referee and and you agree that I'm gonna not smoke or this or that or the other or in this case exercise. And if you don't do it and your referee is you know what you know keeping track of what you do you get to choose something negative. So in her case. Her husband is her referee and if she doesn't walk I can't remember what every day she has to walk a certain number of miles. Her husband will will tell her and and or tell the website and it'll send fifty dollars to the NRA that week oh my God and she hates the NRA with a burning passion what is the name right and the National Rifle Association. They're they're the people who are trying to prevent gun control legislation in the United States and they have effectively prevented gun control like legislation United States which is now kills more children than cars in the United States. So if she doesn't exercise sorry she doesn't do it. Then then money goes to this organization that she hates so that's a this is a stick if there ever was one as opposed to a carrot and I don't think she's every time I see her ask her you know you kept up the walk. He says oh. No the NRA hasn't gotten a penny right so for her. It's been very effective. So it's she's made a commitment contract that that stings right that really hurts now. I think I might be a little on the extreme side and I wouldn't necessarily recommend that to everybody but but she's accountable right. She's made herself accountable in some ways and I think um people can find ways to make themselves accountable to a friend. A loved one a parent you know priest who knows what right um. You might or or hire trainer. That's I mean that's kind of what a trainer does makes you accountable right and I think so so. Those are again social ways to help people be more physically active. So I think there are multiple ways of doing that and I suspect that is going to be the most effective sort of set of tools that will help people. One thing. I actually do is that on the screen saver of my phone it has something that really inspires me. So I see it every day and it's that reminder for me which reinforces my my why across my life. It's actually my home screen on my iPhone is actually a bit of a mood board for me. We have a closing tradition on this podcast where the last guest leaves a question for the next guest not knowing who they're going to leave it for and I don't get to see it until I open the book um.The question is what is one aspect or feature of your life that causes you the most friction slash discomfort and how can you change or fix. It. I would say um. It's my tendency to compare myself to others um. Uh. I you know you know life is short. Life is precious. We're all experiments of one and uh when I think about when I when I when I engage in that oh so and so has such and such um that um. That's a really bad habit. That's a really bad trade. It never leads anywhere good. It only leads towards either either. I think about how I have more of something than somebody else that leads to um uh. I think unhealthy uh feelings of Pride or feelings of jealousy um you know so-and-so has this award or such and such and and uh that's um that's kind of pernicious. So I think that's a bad habit that I uh I work hard to to overcome because it changes your expectations of yourself and that chain takes steals happiness. It steals happiness yeah. It steals. Happiness thank you for the work you do Daniel. Very important very very important and increasingly important. I think um when we look at the the health outcomes especially here in the United States of people. I mean you actually share a number of them in the book which I didn't didn't. We didn't really go into but they're just horrifying yeah um. It's scary out there especially as it really relates to exercise um. There was one in particular that I wrote down because it horrified me. I can't remember it was just all the stats around the current Healthcare. Only 50 of Americans ever exercise ever really ever ever and only 20 meet. Those very minimal World Health Organization standards where where We're a nation of couch potatoes and the rest of the world is headed our way but not if they get. This book because it I think it is a real perspective changer and it's a real eye opener and it's a necessary one so thank you so much for writing it. You're fantastic at what you do and um. I'm I'm now a huge fan of your work after delving in deeper and deeper and deeper um. So I can't wait to see what you do next um well. Thank you and I recommend everyone to go get this book exercised because um yeah. I thought I knew a lot about exercise but uh but from reading that and having that window into a hunter-gatherer ancestors and tribes and other cultures it really that whole idea of a mismatched life how mismatched my life is in so many fundamental ways from diet to exercise to socializing um and these kind of books help to realign. Well thank you. Although it seems that you're doing a pretty good job trying you know I think we're so far from being human though that yeah. There's still a long way to go for all of us so thank you Daniel as you know.Airbnb are a sponsor of this podcast and I was actually in an Airbnb last weekend when me and my friends had a reunion in New York and it's from staying in airbnbs over the years that led me to start hosting my own place. I know friends of mine who actually Airbnb their own place. In order to pay for the Airbnb. They use when they're away on holiday which is pretty smart and maybe you stayed in an Airbnb before and thought this is actually pretty doable. Maybe my place could be an Airbnb it could be as simple as starting with a spare room or your entire place. You could be sitting on an Airbnb and not even know it whether you could use some extra money to cover your bills or something a little bit. More fun your home might be worth more than you think and you can find out how much it's worth at airbnb.com host check it out find out how much your home is worth and let me know what you think uh foreign.