Why Running *Isn't* The Best Way To Get Fit, How The Running Craze HARMED Fitness Enthusiasts & Why Walking Is Essential To Health & Longevity, With Mark Sisson.

My name is Ben Greenfield, and on this episode of the Boundless Life Podcast.

Most people who go out the door, put on their shoes, go out the door, run, they're running at a heart rate that's above their fat max. Their heart rate is too high to be burning fat efficiently, so they're mostly burning glycogen. Their heart rate is too low to be generating any sort of shift in VO2 max or anaerobic threshold or power. So it's this, all you're doing is practicing hurting every day and not getting better. You're not performing better as a result of all of this wasted junk amount of miles that you're doing it at the wrong heart rate. So most people would be so much better off walking a lot more.

Welcome to The Boundless Life with me, your host, Ben Greenfield. I'm a personal trainer, exercise physiologist, and nutritionist, and I'm passionate about helping you discover unparalleled levels of health, fitness, longevity, and beyond.

All right. It arrived fresh and new and shiny, although not so shiny anymore because you guys, you're watching the video version. You can see all these pages folded over. This is, well, it's a book, obviously, but it's a book written by a guy who writes books that I always read, no matter what. I don't even ask any questions. He could probably write a book about something I'm barely interested in, like the intersection between cryptocurrency and democracy or something like that. I still read it. The guy is prolific. He's an OG in the fitness industry. And this book is called Born to Walk. The author is Mark Sisson. Mark, welcome to the show, man.

Hey, good to see you, Ben. Thanks for having me on.

Yeah, sometimes, 'cause I think I've interviewed you twice in the past, I almost take for granted that everybody should know who you are. And then I'll be sitting on an airplane or whatever and I'll mention, hey, ever check out that website Mark's Daily Apple? Which I know, I don't think is in operation anymore. You know Mark Sisson? And occasionally, I'll get an eyebrow raised. So, I know not the entire health industry, or at least all my listeners may not know exactly who you are, but who you are is actually a pretty good introduction to this book because I originally knew you as like the hardcore marathoner, Ironman triathlete, endurance guru. But you're not anymore. And how this book came to be is a big part of that.

Huge. And it's, you know, life is a journey and we learn along the way. And I certainly learned a lot starting at an early age when I was an elite competitor and I got injured and I got beat up by the combination of overtraining, bad equipment, bad shoes, bad diet. And that really set me on my path to, you know, explore human health and performance in general, not just among elite athletes, but, you know, how can we all be strong and lean and fit and healthy? And that really dictated my process for the next, you know, 30 years. This book started out as an anti-aging book and, you know, because I'm 71 now and—

and I should mention, folks, if you don't follow Mark, he's one of the most like ripped fit 71-year-olds on the planet.

Well, thanks. I try. And the irony here is that a lot of the stuff I've learned have been, you guys call them hacks. I don't like that term, but things I've learned over the years that have allowed me to maintain my health and my fitness and my energy and my muscle mass all at the same time without having to make too many massive sacrifices along the way, whether those were sacrifices in diet or sacrifices in overtraining and things that I thought I had to do to be to be, as Ali G would say, well fit. But no. So the book started out as an anti-aging book, but as I got deeper and deeper into the research, I realized, Jesus, so much of this comes back to walking. Walking being the quintessential human movement. And the idea that somehow we lose sight of that, we lose track of that. We start thinking that with a sedentary life that we've created for ourselves, that the best way out of this hole is to go run and put on running shoes and go run 5 miles or 6 miles. And so many people have embraced running as the sort of the ideal form of exercise for humans. And I go back to the book Born to Run, which came out. Christopher McDougall wrote that book in, I think, 2010. And I started to really think about like, what, we're, we're not born to run. We're born to walk. We're born as these bipedal animals that populated the face of the planet by walking, by lifting and carrying things, not running with them, but, but with, by walking with them. And, you know, the idea of 10,000 steps a day, our ancestors got 16,000 or 20,000 steps a day. Um, and they weren't throwing on their shoes and going out for a, a quick 6-mile jog. They were walking. They were, they were living their lives. The idea that we are somehow born to run got, I think it's a, it's a cultural and anthropological misappropriation of a couple of data points. You know, one of the things that, that, uh, McDougall wrote about in his, in his book Born to Run was this notion of the, the persistence hunter and that we evolved eating meat with larger brains and the ability to track animals. And it was these, these, uh, evolutionary adaptations we had that allowed us to run after a beast and then stick a spear in it after we outlasted the beast for 2 hours on the hot plains of Africa. Well, that's not how it works in a persistence hunt. A persistence hunt is sort of like jogging a little bit, stopping, sniffing, tracking, crouching, hiding, uh, cutting the tail.

There's vid— there's videos on YouTube, by the way. You can see how it's done.

Yeah. Yeah. So it, it's done to the point that, uh, you know, like my friend Eric Edmeades. Do you know who Eric is?

Yeah, he's amazing. The wild fit, wild diet. Something like that.

Yeah. Eric, Eric, by the way, he took a pair of, of Peluvas, of the Peluva Desert Boots, my shoes, and he went on a, on a persistence hunt with a Hadza and he said it was no big deal. It's like 2 hours. Like even a, a reason.

That's so funny by the way, cuz I wore your toe boots on my last hunt. They're, they're great for stalking as well. You're like whisper quiet.

No, that, that's one of the things that Eric said was the first time he did it, he did it in like, you know, clunky running shoes. And the guys in the hunt kept turning around and going, shh. And this time you didn't get that. But we digress. So the idea that we're persistence hunters is, it's a romanticized notion. We're born to be able to run, right? We're born to— by the way, the subtitle of the book was going to be Born to Walk, and then in parentheses, and Sprint. But we're not born to run metronomically at 8 or 9 or 10 minutes. Mile pace day in and day out, day after day, over a lifetime. It's literally antithetical to health.

Yeah, yeah. You say, by the way, that it might better be described as the walking, sprinting, jogging, hiding, climbing, crawling, collaborating, strategizing hypothesis instead of the born to run hypothesis.

Instead of the born to run hypothesis. Exactly. So the fact that our ancestors could do this persistence hunt didn't mean that on their days off— look, they didn't do it every day. Once they killed a beast, the beast lasted for however many days it lasted. They didn't have refrigeration, so they couldn't like go accumulate, you know, new animal carcasses and pile them up in their storage area. They hunted out of necessity. So every couple of days, maybe every couple of weeks, they'd go on the hunt. Well, they didn't, on their days off, they didn't train for the hunt, right? They didn't go, hey, let's go do a quick 10-miler so we're ready for the next hunt. No, their life of walking, lifting and sprinting prepared them to be able to run. And by the way, not run 7-minute miles for 2 hours chasing an animal, but to be able to run enough to, to, you know, catch up and get to the next set of tracks or, or, or scents or whatever there was there. So anyway, we, we quickly dispel the notion of humans as born to run in the book, and we talk about Look, we're bipedal. Our bodies literally depend on us walking. We, we, not just to locomote, not just to get from one place to another, but our immune system depends on us being able to, to move and to put, like our lymphatic system requires movement, requires slow, steady movement throughout the day.

BDNF production, VEGF production, you know, Miracle-Gro for the brain. I can tell you right now, you know, even though I get flack sometimes for walking, like I'm doing right now while I'm talking to you. Dude, I feel way more focused, way more energized. My head's in the game way better. I'm getting like 20,000 steps a day and it's incredible for the neural component as well.

100%. So people will say a lot of their best thinking is done while they're walking. I would say that people who are in a low mood want to go outside and change their mood. Walk. You're hungry, you're tempted to reach for the refrigerator cuz you're on a new keto program or a new carnivore or a new, whatever it is, a new way of eating. The quick fix is go out the door and start walking. It immediately starts to mobilize stored fat. You start to burn that fat and you become energized. You lose that craving or that appetite pretty quickly if you do this in the appropriate manner.

Yeah, you get into some of the fat loss calorie burn stuff later in the book and And, you know, just to briefly touch on that, we were talking before the show started. I just moved into my new home. This is one of the first podcasts I've done in my new office. And for 5 days, we're moving, taking boxes out of the truck, hauling them up and downstairs. Best work I can do occasionally. I had the first 2 nights at the home, horrible sleep. And I thought it was because I was in a new sleep environment. I slapped the blood glucose monitor on. I was sleeping at like 50 to 60 blood glucose because I was simply burning more calories walking around the house. I didn't do a single workout. And, you know, I, it reminds me of a text I got from one of my clients. He's probably listening in right now. And he really wanted to start getting fitter, faster, and burning more calories. And he said, you know, I think I just need to start running again. I used to run 45 minutes a day. I want to pick up my run again. Because this idea still permeates the fitness world that one of the best ways to increase aerobic fitness quickly is to simply start running. And you dispel that notion pretty well in the book. But before we get into maybe some of the biochemistry of why walking might even be superior for running for things like, you know, metabolism and weight management, you have a really fascinating section of the book where you get into what sparks this whole myth, if we want to call that, in the first place. It's all endurance running. Craze. I'd love to hear you get into that a little bit.

Sure. Well, you know, we have like, I don't know, first third of the book is dedicated to sort of the, this, this perfect storm of events that happened that created the running boom that ultimately wound up being extremely disappointing for 95% of people who engaged in it. You know, it's fraught with no weight loss when weight loss was intended. It's fraught with burnout, with high cortisol production. With injuries. I mean, runners get injured at a rate higher than NFL players. So in order to set the stage for all of the reasons that maybe running is not the best choice to achieve robust fitness and longevity, we kind of have to go back to the beginning and understand that, as we said out of the gates here, our ancestors didn't, didn't of necessity go out and run just for fun. It was not a fun thing to do. It was a life necessity. And only precipitated on, on the need for more food. When did running really start? Well, you know, you trace it back. Yes, there were Olympic Games where there were sprinters and there were javelin throwers. This goes back to, you know, Greco-Roman times. But really, it's only in the, like, the post-Industrial Revolution in the, in the mid-1800s when cross-country started. And it started as a pub game. It started as instead of darts or trivia in a pub in England or the UK, they would have these hounds and harriers things. They'd rip up little pieces of paper and off would go the rabbits, the hares, and they'd set these trails and the hounds would chase them. And that's where the term harrier came into existence for a cross-country runner.

Wait, I'm assuming that both the harriers and the hounds were human beings and the harriers would just take off running. As like a, like a chase. The hounds would have to catch them. Yeah.

Just a pub game. And it was for, you know, it was to, it was, it was to see who, you know, instead of playing darts, should be outside seeing who was the more, you know, robust runner that morphed into cross-country, which the schoolboys in, in public and private schools started doing cross-country runs where they'd run, you know, 2K, 5K across country on soft surfaces with leather shoes, with great with good form. That morphed into somehow somebody said, you know, there was this guy Pheidippides. There was a poem written about him. Apparently he, you know, he ran into Athens after the Battle of Marathon after running 25 miles to tell the townspeople, rejoice, rejoice, we won. And apparently he dropped dead. We should name a race after him. Let's, you know, let's call it the marathon because the Pheidippides was too, too difficult a word to pronounce. So the marathon only came into existence in 1896 with the first Olympic Games. It was 25 miles. By 1908, when the Olympics, that Olympic Games were in London, um, the Queen wanted the race to start at Windsor Palace and then finish in the stadium. And in order to make that happen, it had to be 26.2 miles. So that's where the, that's where the distance of the marathon.

Oh, interesting. I didn't realize that.

Um, this guy Philippides. Didn't really run into Athens to say, rejoice, rejoice, you know, we won, and then drop dead. That was a poetic license of a poet, Robert Browning. What really happened was Pheidippides was an incredibly gifted athlete who ran over a period of 4 days, ran 306 miles as a courier, as a messenger for the armies to enlist the aid of the Spartans. He ran 153 miles to Sparta. To, at which point he found out the Spartans were on holiday and they couldn't come assist in the war against the Persians. Give us a couple of days. So he had to turn around and tell, run back and tell the general. So if, if we really wanna honor this guy, Philippides, we have to run 306 miles, which nobody's gonna do anyway. So all this stuff is sort of background into how even the concept of humans running long distances came to be. It was sort of a, a human challenge, a game. It wasn't until the 1970s when it really started to take off and this running boom, as we call it now, started to, to take shape. It started with people like me, self-selected skinny people who were, you know, ectomorphs with large lung capacity, a tremendous capacity for pain tolerance, who were willing to go out and run 5K on the track or 10K on the track, or maybe a marathon once in a while. So everybody who started running in the '70s, in the late '60s and early '70s, was basically a runner. Nobody who was overweight would've considered putting on shoes and going out and saying, I'm gonna go run and burn off some calories. It was completely antithetical to health, to any pursuit of longevity or whatever.

I'm assuming because back then it was glaringly obvious that you would get injured really quickly doing something like that if you weren't actually, like you said, self-selected, built to run. Yes. And also running in what back then were the equivalent of, I think something you alluded to earlier, very thin, wonderful shoes.

Ben Greenfield: I started running at the age of 13, so in 1966, in Chuck Taylors, in just basically basketball shoes. And then I was able to get ahold of some Onitsuka Tigers in the late '60s, early '70s. These were the original running shoes in the United States that Phil Knight, later the Nike founder and CEO, imported from Japan. But even those were a quarter inch thick. And it was to the point where in those early days of true runners gifted, like people who self-selected to be runners, it was the shoes that told you when it was time to stop running for the week. It was the shoes that said, man, I think 50 miles a week is tough enough on your joints, on your foot pads, on your heel pads, on your ankles, on your metatarsals. So it was the shoes that kind of dictated how much mileage you put in, right?

Built-in safety mechanism, kind of.

It forced you to run. You couldn't be a heel striker. Oh my God. You'd immediately trash yourself if you were a heel striker. So you had to run with perfect running form and perfect running economy. And even then, it was still, there was still a limit to which your Achilles could take it and, and, uh, you know, your feet or your lower limbs could take that amount of pounding.

Right. And then by, by the way, not, not to insult your shoe company, Peluva, but I can't jog in them. It's uncomfortable. And it really, I could say the same for any minimalist shoe. They totally, totally suck for jogging. Now sprinting up from the mailbox, which is about the equivalent of the running I do, incredible. Cuz I have to maintain good form.

Yeah, so exactly. If you can maintain good form and if you know what good running form is, which not many people do and not many people can accomplish, then my Peluvas are good shoes. But we tell people, don't run in these shoes, do everything else in them. And then when it's time to run, put on whatever.

And when you say don't run, you're talking about the exact form of running we're discussing right now.

Yeah.

Like I think they're the best running shoes I've ever had.

I mean, I could run in them. I could run trails in them all day long, but you know, I know how to run. I know how to have perfect midfoot strike, et cetera, et cetera. So we're, we're digressing a little bit. So what happened was in the early '70s, Bill Bowerman is now the coach of the Oregon, the men of Oregon, the Oregon Track Club. They're some of the best distance runners in the world. Distance running is starting to become a thing. Frank Shorter wins the Olympic gold in '72 in Munich. Running becomes kind of a worldwide phenomenon, at least racing does, worldwide racing. And so Bowerman and Phil Knight get together and they say, let's, let's make it easier for our guys to put in 90-mile weeks and 100-mile weeks and, and more. Let's make, let's put some cushioning in these shoes so that our skinny ectomorphic self-selected runners with good running form can do more miles without beating themselves up. So that was the original, that was the origin, that was the original idea behind the thick cushion padded running shoe. Well, now we, we cut to a few years later. Bowerman has written a book called Jogging, cuz he went to, he went to New Zealand and found out there were people in New Zealand that were doing this little thing where they were kind of running, but they were running slow and he called it jogging. And people are starting to take on, Ken Cooper writes a book called Aerobics. It transformed the notion of heart health and cardiovascular health.

Yep. I, I still talk to doctors today who are heavily influenced by that book and still prescribe aerobic fitness as their primary exercise modality because And even though Cooper sort of backtracked it 10 years later and said, whoa, whoa, whoa, you know, not so much.

Don't, don't do that much. There's a, there's a, there's a limit to which the benefits accrue and then you, they start to drop off and there's a, there's a decreasing return after a certain point, which we talk about in the book a lot with, especially with elite runners. So, so, so with the combination of now an interest in the running boom, books being written on aerobic endurance and cardiovascular health with the notion that now these new shoes would enable anybody to go out and run and not hurt their feet. Now on comes an onslaught of the runner boom. It, it's, it begins in the, in the late '70s. Jim Fixx writes a book called The Book of Running. And it becomes this, this growing ethos that running is the best thing you can do for yourself. And,, and it's, there's a certain amount of, of, uh, struggle and suffer embedded into it, which is, which is good for you. And you know, you're supposed to sweat when you get out there. It's, it's, you know, in contrast to this cushy life that we've otherwise provided for ourselves. So then we see for the next, uh, 20 or 30 years, an increase in the number of people who are running, a decrease in, or, uh, an increase in the, in the, in the amount of time it takes to finish a marathon. Ben, do you know what the average finish time for a marathon was in this country last year?

Oh, fuck. I'm going to guess 5 hours.

Yeah, it was 4 hours and 30 minutes. That's the average finish time. So it's unbelievable to me. Like, when I was running, when there were only runners running, if you couldn't break 3 hours for a marathon, you didn't even call yourself a runner. It was okay. You called yourself a jogger, but you couldn't call yourself a runner if you were competing in a marathon and couldn't break 3 hours. So now we get, we get more and more people coming on this bandwagon. Uh, shoes getting thicker and thicker, form breaking down more and more, people getting bigger and bigger and, and fatter just in society. I mean, 70+ percent of people are overweight now, and yet, and, and no decrease in the amount of running injuries. In fact, there's been an increasing amount of running injuries over the years within the running community. Those people who call themselves runners. 50% of runners are injured every year. 25% of all runners are injured right now at any point in time. 25% of people who call themselves a runner are injured. This is a horrible outcome for what is supposed to be a healthy activity.

Yeah, totally. So, I mean, you were there. I was there. My wife ran cross-country. She was there. You're constantly injured. Or like, what, 15 years of Ironman for me? Not a single week where there wasn't either IT band or or big toe issues or some type of low back problem, like the chronic repetitive motion and friction from that. Yes. And I was light and I was fit, and I can't imagine doing that, like, 30 pounds heavier.

No. So, so many people engage in running. They heard it was the best thing you can do. They sign up for a 10K or they sign up for a marathon. They sign up for a training program, either online or in person. And they start their process of putting in the miles. Well, one of the biggest issues with most people who run is they run too hard for their capacity, for their genetic ability. And the fact that they go out and run 3 miles, 5 miles, 7 miles, whatever it is, and they sweat a lot and their tracker says, oh my God, such a great job. You burned 600 calories. You burned 700 calories. Well, Typically people who engage in this activity are doing so to burn off stored body fat. You know, and when you wanna lose weight, you wanna lose body fat. What happens when you start untrained and you don't build up an aerobic base, which is what walking will do for sure to, for anyone. If you don't build up an aerobic base and you start running, you, you automatically run at a heart rate that is too high for you to be burning fat. So you're burning mostly glycogen in these runs. And it feels valuable. It feels like you're working your ass off. You're sweating. You come back, you're tired, you're exhausted. You just want to sit there and kind of recover for a while. But what's happening is you're burning off stored glycogen every time you go out and do this. And what the brain says is, oh my God, we don't want to tap into body fat stores because we've done this stressful activity. If there's access to food, we need to replenish these glycogen supplies. So typically people replace their lost glycogen with more carbohydrate. As you and I know, going back since we knew each other from day one, you know, carbohydrate is not an ideal choice for most people who are looking to, to learn how to burn body fat. And over time you see people not only not losing weight, you do see their body composition changing because Running is catabolic. Running is catabolic. It tears muscle tissue down. So over time, somebody, a woman might say, well, I'm 155 and I've stayed at 155 for the last year since I've been running. She's lost some muscle mass and she's gained some body fat. Her weight stayed the same, but her body, her composition has changed.

And possibly a short-term, somewhat rewarding decrease in overall weight because glycogen carries up to 4 times or more. It's weight in water. Bingo. So you lose water, you lose glycogen, you—

well, and you, because if you're going from a sedentary lifestyle, which is pro-inflammatory in and of itself, you lose, maybe, maybe you lose 4 pounds of systemic inflamed water weight that you carry just from an inflamed lifestyle otherwise. So it's not unusual for people to lose 10 pounds, you know, their first 4 months of running and go, oh my God, it's working. Well, not if you're not burning fat, it's not working. In the book, in, in Boardwalk, we talk about what it, like some of the metrics we would use to decide if you are acclimated to running. If you, for instance, we use it, we use the term the Maff heart rate or the fat max heart rate or zone 2, whatever you wanna call it. It's in the book, it's 180 minus your age. So let's just say you're a 40-year-old man and you start running. If you, if you're running at a snail's pace and your heart rate's above 140, you're not in your fat burning maximum zone. You're not in your fat max zone. You're, you're, you're basically in what we call this no man's land of training. It feels like you're doing the work, but you're only burning glycogen. You're not burning fat. Most people discover when they start this process that, that, that they can, they can only stay at or below zone 2, at or below the prescribed fat max heart rate. If they're walking. Now, walking doesn't mean walking slow. You can walk briskly.

Yeah. I mean, and by the way, I use this strategy for Ironman training and would often find myself walking on hills when I first began, just because I would exceed that aerobic threshold if I didn't. Yes, it was a little embarrassing.

Yeah. And by the way, if you're walking hills in an Ironman, you're not going that much slower than if you were running those hills.

No, sometimes you're going faster.

Yeah, exactly. Exactly. So I want people to understand that walking is an amazingly— it's certainly beneficial. It's quintessential human activity. But there are all variations of walking that you can be doing, all of which accrue to your fitness level. But back to the running thing. Most people who go out the door, put on their shoes, go out the door, run, They're running at a heart rate that's above their fat max. And so they're not— what's happening is they're what we call the black hole of training. Their heart rate is too high to be burning fat efficiently, so they're mostly burning glycogen. Their heart rate is too low to be generating any sort of shift in VO2 max or anaerobic threshold or P speed or power. So it's this— all you're doing is practicing hurting every day. And not getting better. You're not performing better as a result of all of this wasted junk miles that you're doing at the wrong heart rate. So most people would be so much better off walking a lot more and then sprinting once in a while. And make no mistake, I'm a huge fan of sprinting. Sprinting doesn't have to be on the track. It doesn't have to be running. It can be rope pull. It could be rowing machine. It could be bicycle. It could be assault bike. It could be any number of pickleball, ultimate frisbee, any, yo, exactly. Any, any of these things where you get your heart rate up to a max for anywhere from 10 seconds to 30 seconds. And yeah, that's an, that's an integral part of, of increasing VO2 max. But, but the fact that you think you would go out and run 4 miles a day every day, 6 or 7 days a week, and somehow improve your running economy to improve your body composition, it doesn't happen. One of the things that you sacrifice in doing that is you sacrifice energy for enjoying the rest of your day, going out and playing ball with your kids, or going on a long walk with your dog, or raking the leaves, or whatever other activities that your body wants you to do throughout the day. So many people think, well, I already did my activity. I did my 4 miles. I'm done with activity for the day. That's not how the body operates at optimal efficiency. The body wants to be moving pretty much throughout the day, which is why what you're doing right now, you know, you're multitasking. We call, I used to call it productive leisure, but you're having a podcast while you're walking on a treadmill. I mean, when I started Primal Kitchen, the food company, I bought everybody in the company a stand-up desk and a treadmill, and it was amazing.

Yeah, it's incredible. That's why the ketchup tastes so good. Yeah. So besides the risk of injury, the induced state of hypercortisolemia, the shift from a fat oxidation state to a carb oxidation state, or the inability to shift into a fat oxidation state in the first place, you haven't addressed what I think is also, and correct me if I'm wrong here, one of the big stinky elephants in the room, and that is the gut. It seems to be persistently problematic amongst most people who run that they're in this constant uphill battle against their gut. What's going on with that?

Well, different strokes for different folks. I think something like 30 or 35% of all elite endurance athletes have gut issues that cause them to have pre-race problems. I was one of those guys for sure. Inter-race problems. I mean, in the best marathon I ever ran, I ran 2:16:37 in a mar— in the, in the national championships in Saratoga, California, 1980. I had to stop at the 15-mile point and, you know, and not just, and not take a leak, shall we say. Yeah.

I learned early on, don't give your fellow athletes bear hugs after the race.

Yeah, exactly. Yeah. And we see, you know, you see the memes on, on Instagram today about the, the gal, the triathlete who just said, you know, I just shit my pants. Please don't get me from the, from the waist down. Did you see that one?

I didn't know. No, it would've been, it would've been painfully, it would've been a painful memory for me. 'Cause I've, I've had that happen too many times. Yeah.

Yeah. Anyway, what's ca— what's happening? Well, first of all, I mean the, like the most egregious example, Julie White, who won the Canadian Ironman a bunch of years ago after she finished the race, was rushed to the hospital to have a bowel resection because her, she, she had been ischemic. Her gut had been ischemic for so long that part of her intestines died. She had like 12 inches of her colon removed. That's an example of, that's a real dramatic example of mind over matter. So she was hurting so bad, but she forced herself to finish. What's going on is when you're running this much or doing this much activity, you are diverting blood flow away from the digestive process to the muscles, which are working. So the more the muscles are working and the harder they're working and the higher your heart rate, the less is being allocated to digestion. So a lot of people have issues with digestion in that regard. In my own case, my understanding at the time, which was that carbs were gold and you had to carbo-load every day to be able to go back and do it again.

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That's it. So I had a pretty heavily grain-based, sugar-based diet. So my gut was always reeling from whether it was, you know, leaky gut syndrome or just other issues with folded, you know, tightly folded proteins, you know, the gluten, the gliadin, or whatever. I had all sorts of issues with the foods that I chose to eat in order to top off my glycogen stores because I thought that was necessary to get better as an athlete and to continue to train on a day-to-day basis. I suffered from that for almost 40 years.

Yeah. And obviously much of this can be mitigated with, you know, colostrum, L-glutamine, you know, KPV peptide, et cetera. But I think, because some people might be wondering, you know, well, I lift weights, it probably does the same thing, diverts blood away from my gut. And that's true. But I think the difference is that when we're talking about running, particularly, you know, marathoning and beyond, you're eating while you're out there.

Well, you're eating while you're out there and you're also, you're not resting. You're not stopping to rest. You're, you're con— so you're lifting weights, you know, you take 90 seconds in between, you let your heart rate come back down. I mean, even if you're doing a high intensity, you know, session, which I, I talk about in the book, you should only do that once or twice a week anyway. I mean, it's not like I, I, I see all these, you know, cardio bunnies doing, you know, Orange Theory 4 days a week and then spin classes the other, the other 2 days.

That's not, that's not high intensity though. Tell, tell people why that is. Tell people why that is not. What is actually studied when you see HIIT in exercise literature versus HIIT on the wall of F45 or whatever.

HIIT is Wingate. HIIT is Tabata. And not, and by the way, Tabata, not, you know, like 8 sets of Tabata because, because, you know, you automatically meter out.

Doing a half hour of Tabata is my warmup.

Yeah, exactly. It's like, that's not Tabata, pal. Yeah. High intensity is high intensity. When I say max all out, I'm talking max all out. And I'm saying don't do it more than once a week. Maybe if you're really good at it, twice a week. But for most people, they think they're doing high intensity stuff and they're, again, they wind up in that black hole, that zone of training, that no man's land where they're not— they're going too hard to be burning fat and they're burning glycogen and they're getting exhausted and they're producing cortisol, but they're not going hard enough to generate either power or explosive power or sustained power. Or VO2 max increases or anaerobic threshold, any of the high-end stuff that elite athletes seek in terms of really measuring improvement and ability to sustain a pace at a high output. All you're doing is struggling and suffering and practicing to hurt every day without getting better. And the example I refer to a lot is And I know, you know, a lot of these people, we see a lot of internet influencers and they're like, yeah, I'm a marathon influencer and I do 6 marathons a year and I'm, you know, I'm 34 years old and I can run 3:24. And I'm like, okay, uh, A, I'm not impressed. B, if you're not getting any better after all the training you do, you found the wrong sport.

It's just, you're so jealous of their number of followers right now.

I am. It's, and they have the followers and I'm like, I'm like, okay, this is, this is like me. If, if Mark Bell said, you know, um, you know, my bench record is 164 and, uh, my squat record is 85 pounds and I'm a weightlifter. No, you're a dude that goes to the gym and lifts weights, but you're not a weightlifter. And, um, and I feel the same way. Like if, if, if you are not running at a competitive level, then you're just beating yourself up on a regular basis with no positive outcome. You're certainly not improving your longevity prospects. I guarantee you, if you're doing 6 marathons a year averaging 3:20 or 3:40 or 4 hours or whatever it is, all you're doing is accelerating the aging process in the name of feeling somehow feeling good about what you're doing because It hurt and you got through it and onto the next thing. It's kind of the David Goggins effect, which is, and by the way, you know, great example. I mean, David has changed a lot of lives, but the guy beats himself up relentlessly.

Yeah. I don't want to get negative or like throw people under the bus, but sometimes that Navy SEAL, I'm injured and I'm going to push through no matter what. I'll sleep when I'm dead philosophy. Yeah, it's inspirational, but I think it's really not doing people a service. And I'm sure that you've been doing several podcasts leading up to the release of this book, Mark. So, I imagine you've gotten this pushback from folks who might say, "Man, how could you say that about fitness influencers, about people just strapping on their shoes and getting out there and moving, baby, and starting to change their lives?" And, yeah, they have the identity of an athlete now and they're running. How could you just throw a bunch of water on that gasoline.

Well, you know, it's, it's not, like I said, with Goggins, I'm like, he's changed a lot of lives. I'm not going to dispute that. Um, how, you know, how he, uh, forces himself through all of that is beyond me. And as an example to the rest of the world, I guess that, that's fine. That works. Um, as a metaphor maybe, but not do as I, you know, do as I say, not as I do. Um, on the other hand, you know, a lot of the influencers are, you know, What I see is you gotta put the time in, you gotta struggle, you gotta suffer. And my pushback to their pushback is you don't have to suffer. There's ways to do this that are gonna generate improvement in performance that are gonna make you healthier, that are gonna keep you from getting injured. Look, I mean, the injury rate among marathon trainers is, it's unbelievable. And much of it is due to the footwear. Much of it is due to the shoes. And yet people are, they're pimping the newest brand of thick cushioned, whatever fly shoes that they're training and racing in. And then once they finish, once they've gotten 400 or 500 miles in 'em, they relegate them to walking around town shoes, which is just as bad.

Which, which have a time and a place where like, I have a pair of basketball shoes. I'm not gonna go on the courts barefoot or with—

I'm not telling you what I'm saying.

Cause it's a court shoe, you know, train.

Absolutely. When it's time to go race a marathon, put on your you know, put on your running shoes or not, or go rock climbing.

You're going to have a compressed toe box. Deal with it. Like, you know, there's a time and a place.

Hockey players. I mean, Jesus, nobody's got a more restricted foot than a hockey player. So, but wear your skates because that's what they're for. But when you're spending the rest of your day moving around, put on shoes that allow your feet to become, you know, more mobile and resilient and stronger over time. So you're less able, less likely to, to twist an ankle or whatever. And the same goes for running, you know, so much of what happens to runners as a result of overtraining and overstressing their bodies. These injuries are repetitive use injuries that could be avoided if they spent some time in the gym. I would suggest that for many of the so-called runners, walk more, run less, spend some time in the gym, get stronger, sprint once in a while, but cut your miles way back. If you say, but Mark, I'm a runner, and I say, well, what does that mean? Well, to me it means I run 5 times a week, 6 times a week. My response would be, what if you ran once a week, 6 miles, and every time you ran that once a week, you got faster and faster, faster than every workout you ever do as you accumulate your 30 or 40 miles a week? Wouldn't that be— would you not call yourself a runner then? I mean, the identity, runners having an identity as and what we call an obligate runner, somebody who feels compelled to have to run every day or else their life is incomplete.

That's where my sons talked me into doing a DEKA fit last year. And I continue my normal habit of walking 15,000 to 20,000 steps a day. I put in one running day. It was a circuit. We had a quarter-mile circuit at our house. So I just run almost like a 400 on that circuit, stop, do one of the DEKA fit exercises, do that again, about an hour-long workout. I did that once a week for the 12 weeks leading up to the race and took top age grouper in the race by walking, which for you and me as former endurance junkies know the top age grouper doesn't say much, but I didn't run that much at all. It was once a week.

That's my point. That's my point. I mean, in a book that preceded this called Primal Endurance, which I really first started to develop this notion of spending 85% of your time at zone 2 or less, 80% of your training time. I noted the fact that once I retired from competing and I started coaching professional triathletes and I had to make a living because professional triathletes don't pay that well, and I was training ordinary citizens to become fitter. So I spent much of my day walking with my regular clients, not even jogging, walking, walking, walking, walking. Doing light weights, doing maybe some easy stair climbs. And then once a week I'd go to the track and do a track workout, and I would jump in some of these elite races that I was traveling around the world with my pro athletes, and I'd enter the age group thing and I'd win my age group. Same thing on minimal training. When I say minimal training, it was a lot of low-end aerobic base building, and then just once in a while doing that high, really high-intensity stuff. To not only maintain my fitness, but in many cases to improve my fitness. And then jumping in a race once a month, I jump in a race. I mean, one year the Desert Princess Duathlon, which was the number one duathlon in the world for years, I finished 11th overall, won my age group by far on this sort of minimalist training with lots and lots and lots of low-end aerobic stuff, walking and maybe a little bit of easy jogging, but even the easy jogging was zone 2 or lower. Yeah.

Running every day sells lots of shoes though.

That's the problem. That's the issue. And what's funny is, no, you know, we now have the new shoe company, Peluva, and we're talking to a lot of running shoe store owners who will say, don't tell anybody, but 85% of our business is walkers. Most of our people who buy our shoes don't run. They're walking. And a lot of them are walking because they're injured and they can't run, but they want to do something. By the way, when you're injured running, what do you do to come back from running to, to, to, to return?

You walk. I was going to say, I mean, I used to do those boring shoot-me-now aqua jogging sessions, but yeah, also walking.

Yeah.

Yeah. So, so explain, explain this to me because I'm a little bit confused about this part. There's so many longevity enthusiasts and physicians talking about zone 2 training. You talked about the aerobic threshold about, you know, maintaining a conversational pace. If you were going to use that Maffetone-style training philosophy, but zone 2 often is still running. Would you consider walking to actually be zone 2, or is it so depending on your fitness and, and can you, can you get as fit?

Yeah. So, so zone, zone 2 for a lot of people, people can run in zone 2, and if you can run in zone 2 with good form, then go for it. But what we're saying is most people, if you do this test and you go out and say, You know, how do I put on a heart monitor and, and, you know, I'm trying to stay at or below, not above, uh, zone 2. Um, you know, what kind of pace is that for most people? Once they break into a trot, once they're running a 13 or a 12 and a half minute mile, which is kind of the cutoff point between walking and, and, and brisk walking and running. Um, they exceed that heart rate and they have to drop back to a brisk walk. So if you can maintain a run pace at zone 2 or below, go for it. As long as you're maintaining good form. 'Cause form is part of this. You know, we don't want you to get injured. And good form for me means you're running with a midfoot strike. Your biomechanics are such that your, you know, all of your kinetic chain is functioning appropriately. So there's no one. Part of your kinetic chain that is overburdened because of a lack of input from the bottoms of your feet. There's a lot of nuance to this. What I do for like my favorite workout, I go to the south of France every summer. My favorite workout is a hike that I do. It's about an hour and 20 minutes and I run part of it, but I run until I lose form and then I walk. And I walk for 5 minutes and then I run until I lose form and I walk. And at no point is this ever more than 400 meters that I'm running. And when I say lose form, I get tired. My, you know, my calf gets tired or whatever. I'm happy to just start walking again. That to me is the ideal mix of running and walking. And that's your, that's your Ironman training that you just referenced, you know, right? You, you run a little bit, you walk a little bit, you run a little bit, you walk a little bit.

That reminds me of my Sunday afternoon frisbee golf sessions. We run the hills, we do 10 pushups, 10 burpees, or 20 air squats at every hole. I know this is probably near and dear to your heart because your co-author Brad does speed golf at a very impressive pace with a very impressive score. But that kind of leads me to a little bit more of a practical question for you. And I might have a few of my own to add, but your favorite ways to walk besides just walking, like things that you do during a walk to amp up the intensity or trigger another physiological system, anything like that?

Yeah. So I love rucking. Rucking is a great way to add some weight-bearing activity to your walk.

Are you a weighted vest or a backpack guy?

I'm a weighted vest mostly, but I do some rucking. I do a backpack. But I'm in Florida, so weighted vest works really well for me. I do a weighted vest. I walk as part of my leg day in the gym. I'll do 12 to 15 minutes backwards at a 15-degree incline on a treadmill with a weight vest on as part of a knees over toes, you know, concept as a warmup for the legs. I skip once in a while. I love, I love skipping. I mean, like I'm skip rope or just, just, no, no, skipping, just skipping. I mean, I'm a, I'm a, you know, I'm a cis male, but I still like, I still like skipping and it's, it's fun to break into it. It's a little bit of a, there's a, there's a little bit of a track and field drill aspect to that. Brisk walking.

Bounding is technically plyometrics. Correct.

One of my favorite things is go off-road. I look for cobblestones because I'm wearing minimalist footwear. I want to feel everything underneath my feet. I will, we call it foot candy. I look for different surfaces to walk on. One of my favorite workouts I've done in the last year, I was in Kona, and you know how the lava fields of Kona are, they're cooled, the ones near the ocean, but they're so crusty and gnarly and up and down. I spent 45 minutes walking on a lava field one day. It was the best foot workout I've ever had.

My feet, I've done a lot of hunting out at the base of those volcanoes and your feet are just toast at the end of the day.

Yeah. But they, but they're toast in a good way, right? Because if you're not running on them, if you're not putting 7x the G-forces, um, just, just landing and responding and pushing off from a different, uh, plane or platform or direction or tilt or texture every time, every footfall strengthens your foot in a good way. Versus wearing stiff, thick cushioned shoes where you can't feel the bottom of what's going on and your brain has to guess on how much to bend the knee. Or do I not even roll the ankle, but do I absorb all of this by bending my knee the wrong way outward? So there's lots of ways to walk. I mean, look, speed walkers in the Olympic Games, they can hit 6-minute miles speed walking.

I know my exercise phys professor at University of Idaho, Dennis Dolman, he was a speed walker. He took us out on the track once. I just, crushed us. Like even the shin splints alone, you talk about heel striking.

Yeah, I know. That's, that's, that's, but that's not heel striking in the same way that running heel striking is, right? They're planting and rolling, planting on the heel, rolling off. But they're, they're, they're the sort of exception, uh, on the, on the, on the walking front, but they're still walking in a way that is biomechanically sound. They plant the heel, roll off the big toe, plant the heel, roll off the big toe. That works as a walking gait. It does not work as a running gait. Yeah.

I'll throw a few more. Yeah. I wanna hear your opinion on these. Playing with your breath when you're walking. You know, I have some of these breath devices. They're almost like a whistle and you put 'em in your mouth and you, you're forced to breathe through your nose and then you breathe out typically through pursed lips against resistance. So it's almost like you're doing Buteyko breathing or carbon dioxide retention. While you're walking, your heart rate's about 10 beats per minute higher, but you saturate your body with carbon dioxide during that protocol, and you're also doing nasal breathing the entire time.

Interesting. Love it. I'm gonna try it. Yeah, so I do nasal breathing a lot. I mean, I'm focused on that, and I'm focused on pacing. I mean, I'm a counter from day one, so it's 2 in, 2 out, 3 in, 2 out, whatever the pace is.

Whole book about that, Running on Air.

Yep.

Yeah. Yeah. Okay. So how about thermal stress? Do you ever do, like, obviously you live in Florida now, so you don't do this, but I'll often do minimalist clothing, often gloves, hat, wool socks, shoes, and walk with thermal stress, do like a cryotherapy walk.

Yeah. I mean, because I'm in Florida, that happens automatically. So I'm not doing thermal walks as much as I'm doing thermal bike rides. You know, if I'm doing fat bike on the sand on a hot day, like I usually go out at 11 or 11:30 in the morning. It's like literally the hottest part of the day. Sun's highest. And I love that stuff. And, you know, I wear a heart monitor whenever I work out. And I'm usually 10 or 15 beats a minute higher than that same effort would be at room temperature, maybe even, maybe even higher than that.

And by the way, the heart rate thing, that reminds me, Joe Mercola, back in the day. He was telling me that when he was recovering from a heart issue, he used a very, very expensive hospital machine called Enhanced External Counterpulsation. It's basically like a compression gear that compresses, and it compresses timed to the diastolic beat of your heart, allowing for a much, much greater return of blood flow to the heart. And he told me about this device. I got it and used it for a couple of years called a CounterPace. It's a, it's a chest rate or chest strap. It detects the diastolic phase of your heart and then does a little metronome to adjust your walking cadence. So with each strike of your foot, you're actually pumping blood back to your heart and it teaches you how to time that. It's almost like breath running on steroids.

Yep. No, interesting. I mean, all these things, look, I think, I think walking has, it's been cast aside. It's been relegated to the trash bin of of workout options unnecessarily because people think that everything else they're doing is so much more valuable, especially if they're compressing it into 10 minutes or 15 or 45 minutes. When in fact, walking, I think we're entering a new phase of walking being recognized as the quintessential human movement and something that, that there are so many ways in which we can optimize our health through things that you've just talked about, this optimized breathing, this, you know, the cardiac output, you know, vagal tone, HRV, whatever it is you want to talk about. There's so much opportunity here to use walking as the aerobic base building, the foundation of everything else we do. And I'm excited to promote, I'm certainly excited to give runners permission to walk again. Look, I was one of those guys when I was a runner. There's no way I was ever going to walk anywhere. If I had to get from point A to point B, I ran.

Yeah. Okay. So, I would be remiss not to ask you one last thing because I'm just intrigued by your productivity, your energy, your vitality. I've always looked up to you as a guy who accomplishes a lot in the fitness industry in a very approachable and ethical way. And the routine of high achievers is something that I think often tells you a lot about how you can tap into some of that same success. So, I realize your daily routine could take you an hour if you wanted to, but give me or give us just like the lightning round overview of what Mark Sisson's day looks like when you pop out of bed in the morning.

I mean, it's more routine is the right word because I really crave that routine. And, if I get off my schedule, I get a little bit upset. But no, get up, I don't know, 7 o'clock, have a cup of coffee, read. I read 2 newspapers. I skim 2 newspapers for what's going on in the world. I actually read physical newspaper.

What's a newspaper?

Yeah, I know. Exactly. Then I do probably half an hour worth of puzzles, word puzzles. That's kind of my hobby. Hobby. I get to work, do some email, do some writing, do some calls. Break at about 10:30 and do my workout, whatever that is for the day. Understand that by then I still haven't eaten yet, so I do my workouts fasted other than the cup of coffee. Some days it's, you know, I do weights twice a week. That's upper body weights twice a week. I do legs once a week. I do a fat bike once a week. I do stand-up paddling once a week, and then I fill in a lot of the gaps with walks. So, I'm walking every day. By the way, I just had a hip replaced. 5 weeks into my hip replacement, I'm probably 95% back. I mean, I'm stunning myself how I rode 45 minutes on a stationary bike today. Pretty hard. It's so funny. Pretty hard. I was looking at it. I was in zone 2, maybe zone 3, level 15 for 45 minutes on a LifeCycle, cranking out what amounts to about, I don't know, 180 watts. Which is, you know, for a 71-year-old guy isn't bad. And my heart rate's not that high and I'm, and I'm doing the work. I stretch a fair amount now. So anyways, that's my workout. I break around 12. If I have time to go back and do some stuff before lunch, I do that. I usually have lunch around 1. It's usually just a piece of protein with some kind of vegetable around it. Not a big meal. Work. In the afternoon, I have a lot of podcasts. I do podcasts 4 or 5 times a week. More writing, more thinking. I have meetings, you know, I have team meetings with Buluva a couple times a week. And then up until maybe 6 or 6:30 recently, I go down to the sauna and I do a 20-minute sauna. We have a, I live in a building where we've got a nice little spa at the bottom of it. Come back, have a, you know, have a cold shower and make some dinner. Dinner's again, usually a large steak with either a salad or some kind of green vegetable, a glass of wine or two. And that's it. Now, throughout the course of the day, I'm in the meetings, in the writing. I'm, that's, I'm productive in that regard. I'm, I'm, I'm an idea guy. I'm a big picture thinker. So I'm working with my team, whether it's my writing team, at Mark's Daily Apple, whether it's the book team with Brad, whether it's, you know, Instagram or Twitter. I'm the idea guy, and then I've got great people around me who are able to execute based on these wild-ass ideas I have about life or about what we should be making.

Incredible. I get it. I'm the idea guy too, much to the chagrin of my team sometimes when I, you know, I'm off traveling, I come back having read 4 business books, and all of a sudden the Slack channel has 11 new ideas in it. What an incredible day. And folks, he did kick my ass on that fat bike the last time I was in Miami. So caution if you're ever out there on the fat bike with Mike.

Mark, you loved it, but you loved it, right?

I love it. Yeah. The book is Born to Walk. All the show notes are at bengreenfieldlife.com/born2walk. If you grab Mark's book, I can tell you he's got a pretty prolific Amazon library. All of his books are good, but this new one, will really change the way that you think about running. Check out his company, Peluva. When you see me with those funky looking toe shoes on, that's the brand I use. Nice wide toe box, good fashion. You won't even look dumb when you're skipping. And then finally, even though he's sold the company, Primal Kitchen Foods is pretty much the only ketchup, mayonnaise, mustard, et cetera, in the Greenfield pantry. So Mark has created a lot in the industry. Check out all of his goodies, and I'll, I'll produce some juicy show notes for you at bengreenfieldlife.com/born2walk. Mark, thanks so much, man.

Thank you, Ben. Great to be with you as always.

It's fun once again. All right, folks, signing out from Ben Greenfield Life. Thanks for listening.

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