I want to shift us to rocking. I really dislike rocking, but now you got me rocking. So tell us why rocking and things like it are so valuable and are distinctly different than like, quote, unquote, hitting the gym. So I'll tell you how I sort of came to this realization, started writing about this in the first place, is that when we were in the Arctic, we're hunting, right?

So when you look at why humans are good at running, and by the way, we're good at two things. We're good at running and we're good at caring. And I'll tell you why we're good at caring. So the reason we're good at running is because we evolved to run long distances to chase down animals in the heat and spear them.

So humans are really good at cooling ourselves in the heat, right? And we can run these long distances. Other animals can't manage their heat. So we'd slowly but surely run down animals. Eventually, they would get too hot, they'd topple over from heat exhaustion, and then bam, we'd kill them.

Okay, so this is a theory called, it's called persistence hunting. So we won the thermoregulation game. We run the, won the thermoregulation game. Yeah. So we can, we sweat, we don't have much fur, and then our bodies are also designed for this type of persistence hunting. There's a guy at Harvard, Dan Lieberman, who had this, I think it was in 2004, paper about this, how the reason we're built the way we are, one of the key reasons is so we could run long distances for persistence hunting.

So I'm familiar with that research, right? I'm like, oh, that's really interesting. Cool. I'm like, yeah, this explains why I have like, you know, these big butt muscles, these arched feet, whatever. So we go up to the Arctic, we're hunting, eventually successfully hunt a caribou, and we, you know, we're taking every usable part of it we can, so we load our packs with all this weight, it's like a hundred something pounds in this damn pack, and start walking back to camp.

And I'm just thinking about this research about, okay, humans evolved to run long distances so we could hunt. Great. But what happens after you actually kill an animal? You got to carry that damn thing back to camp, right? And so it occurs to me, well, wait a minute, we're also pretty unique among animals in that we can carry weight.

Like no other mammal can just pick up weight on its own and carry it a long distance. It's like, huh, that's interesting. So I just start looking into this, and yeah, humans are the only mammal that can pick up a weight and carry it a long distance, and it absolutely shaped us into who we are.

It allowed us to really conquer the globe, because we could take tools into the unknown, right? We can walk, we can cover these long distances in our two legs and our feet. Our hands are freed up to carry our tools, to carry whatever it might be, and it really turned us into who we are.

Now, the thing is, is when you look at running, plenty of people run, right? Like running and marathons, that is a popular activity. But how many people are just like carrying weight as a regular form of exercise? The answer was really not that many. So I'm thinking like, okay, who actually still maybe does this?

And it turns out it's the military. So rucking is sort of the main activity of physical training in the military, just throwing weight in a backpack and going for a long walk. And I've actually started to sort of even shift my language from using the term rucking to simply saying walking with weight or weighted walking.

And the reason for that is, is if I tell my mom, hey, you should ruck, she goes, oh, okay. And she types in ruck and she goes, the hell is this military stuff, Michael? I'm 75 years old. So I've started to call it more walking with weight. So it's a little more approachable for the masses.

But I think the benefit of it is that you're getting cardio stimulus because you're covering ground. But you're also getting strength work because you've loaded your skeletal system, your muscular system. And that comes with a lot of benefits. You kind of got this two in one. So it generally will burn more calories per mile than walking or running.

And that is simply because you've added extra weight. Of course, if you're running, you might cover more distance in the same amount of time. But if you just compare it by distance, it's burning more calories. And I think it's one of these activities that can really fill in gaps in people's training.

And to what you sort of alluded to in your question is there's a variety of reasons it fills in gaps. But one of them is simply that it gets people outside. Like there's a lot of gym people who are like, yeah, I lift all the weights, but like I'm not doing that running thing.

A lot of people can't run and like, oh, by the way, walking feels a little too easy. I'm not going to do that. So if you can throw some load on someone and have them go for a walk, it gets them outside, helps them preferentially burn fat, it seems compared to something like running.

So there's this interesting study. And I'll caveat this by saying it was a very small study. I think it was only 12 people because they could only find 12 crazy enough people to do it. It was on backcountry hunters in Alaska. And so these guys carry these heavy packs out into the mountains for a week or whatever.

And they test them and they ended up losing a significant amount of weight, but it was all from fat. They actually gained like a very minute amount of muscle. And that really shouldn't happen in the context of going out and losing weight, right? You're probably going to lose fat along with muscle.

But with this, they ended up losing mostly fat. So I just think it's this amazing activity that we really wove out of our lives due to technology. Humans evolved to carry. People were carrying babies all the time, like every day in the past. We'd go hunt and we'd have to carry all the meat back to camp.

We would carry food that we gathered, like gathering. We're hunters and gatherers. Gathering is literally walking around, finding some food, carrying it, finding more, carrying it back to camp. And then we got, you know, cars. We got grocery carts. We got XYZ. We got furniture dollies that we don't carry as much.

And I think we've lost a really important form of human movement and physical activity that we're literally born to do. And so my suggestion to all the listeners is get some weight and carry it. Easy to throw some weight in the backpack and go for a walk. And it'll be good for you.

How much weight and how far? So if someone is just starting, I tell them to start light. I think, so after I published The Comfort Crisis with the, there's a chat, there's an entire chapter on walking with weight or rucking. I got all these people in the military, rucking destroyed me.

Okay, well, how much did the military start you with? A hundred pounds. It's like, well, yeah. It's like, if you did anything at that intensity immediately, just immediately went into like the red, you're going to get injured. You know, it could be squatting. It's like, yeah, I tried to max out on my deadlift every time I deadlifted the first time I deadlifted.

Therefore, no one should deadlift. You need to ease into this. So I tell people, women can start with anywhere from five to, say 20 pounds to just, um, men, anywhere from 10 to 30, depending on your fitness level. I would rather have someone really ease in and sort of get used to it.

Cause a lot of people will say, yeah, I went a little too heavy and it really sucked. Like I want you to sort of on ramp slowly. And then from there you can build up over time. And so I have plenty of, you know, women who might weigh 130 pounds who now use 30 pounds, which is a significant amount of weight.

Um, I'll have men who, you know, maybe they started with 20 and they're like, that's way too light. Like I, I just have too much of a base of fitness. It's like, okay, good. Well, I'm glad we started there though. So we know for sure. And then they've ramped up to say 40, sometimes 60.

I mean, for me, I generally, my sort of go-to weight is probably 35 to 40 pounds. And I find that that's a weight where it's uncomfortable. It's challenging, but it's also not so soul crushing that I'm like, I got to end this walk. I guess this absolutely sucks. I can still enjoy it.

And of course I'll go heavier. Sometimes if I'm going really far, sometimes I might be like 20 pounds or something. You know, I think it's really just like start light, take a walk, see how that feels. You know, it doesn't have to be too complicated. Yeah. I said, I hate rocking, but, um, I love the way I feel afterwards.

Maybe that's the form of exercise. I don't like there. I just outed myself as not liking. I find that, um, it forces me to pay attention to some of the smaller stabilizing muscles. Like you can't be as loose with your gate. You have to be pretty thoughtful, especially if you're hiking.

Um, you can't stride too long here or there. You, you just naturally keeps you moving more like a pack mule, uh, which I think can be helpful. Um, and I do notice that when I take off the rucksack or the vest, um, on a different day and I, and I run, I definitely feel faster and lighter just by way of comparison, probably a real, real change too, due to the state small stabilizing muscles.

This thing about losing more body fat, we'll get, we'll get people motivated. Yeah. People love, people love that. I think it's also a good tool for runners because the injury rate is much lower. So if you're within a reasonable amount of weight, like of course, if you go up to these crazy weights, so I generally tell people, if you just want like a firm number, don't go over 50 pounds.

Um, if you want a more sort of dialed in number to your body weight, don't go over a third of your body weight. There's a lot of military research that suggests that, but even for me, like I don't go up to a third of my body weight all that often, unless I have a really good reason I'm training for something like backpacking or hunt or something.

Um, so if you're in a, within a reasonable amount of weight and not too heavy, um, the injury rate is exceedingly low. It's not that much higher than the injury rate of walking and walking is pretty safe. Do you ever experience the kind of, uh, crossover of understanding between, uh, your physical pursuits and your, um, creative intellectual pursuits?

Like, do you find that for instance, if you, you rock that there's a certain, that you start to recognize where the resistance is, is it putting on the pack? Is it, uh, you know, a third of the way through you tend to feel pretty good. Do you notice those contours and do they map to the contour of sitting down and, and writing, um, that it's hard at first, then it gets easier.

And then at some point there's a breakthrough or else it just plain sucks the whole time. I think so. I'd like to hear your experience with running, but my experience with running is that the first, say three miles, they suck. You know, this is hard. Like things just start, you just feel like resistance.

And then eventually, usually after say mile three, all of a sudden I feel like, oh, I could do this forever. I could do this the rest of the day if I wanted to. But if I don't go through that first three miles, I'm never going to get to four plus or whatever it is.

And I do feel like that's the same, um, with writing where it's, it's challenging at first, the things aren't moving, but then things just, things start to move, you know, and you, but you need to, you need that buy-in. Like you need the, you're not going to have those amazing four plus miles after mile four or sentence after the 20 paragraphs you deleted.

If you don't run the first three miles or write the first 20 paragraphs.