Barbell Shrugged - How Circadian Rhythms Shape Strength, Recovery, and Health with Dr. Karen Esser #829

Episode Date: December 31, 2025

In this episode, Dr. Karen Esser Professor and Chair of the Department of Physiology and Aging at the University of Florida joins the crew to break down one of the most overlooked performance variables in human physiology: circadian timing. After a career spent studying muscle adaptation, Dr. Esser shifted her research toward the molecular clocks inside our tissues, uncovering how every cell in the body keeps its own time. She explains how these clocks govern fuel storage, protein repair, metabolic readiness, and ultimately the way muscle responds to training. The team digs into what these clocks do, how they synchronize, and why misalignment affects everything from daily performance to long-term health. The conversation dives deep into time-of-day effects on strength, endurance, and adaptation. Dr. Esser highlights that humans are consistently stronger and more explosive in the afternoon, a pattern reflected in Olympic records and decades of performance data. But her lab's animal research reveals something game changing: consistent morning training can shift the internal clock system, allowing morning athletes to achieve equal or even better adaptations after several weeks, despite using lower absolute training loads. She also explains how travel, jet lag, and mistimed eating disrupt organ specific clocks, reducing performance and creating metabolic consequences similar to pre-diabetes. The crew tests these ideas against real world training habits, coaching experience, and what happens when athletes switch from evening to early morning training. Finally, Dr. Esser unpacks the broader health implications of circadian disruption from increased risk of metabolic disease and cardiovascular dysfunction to higher rates of depression and cancer in chronically misaligned shift workers. She outlines simple, actionable strategies: anchor your sleep and training times, keep eating within a roughly 10 hour window, avoid late night calories, and arrive early when competing across time zones. The conversation closes with practical takeaways for athletes, coaches, and everyday lifters who want to maximize adaptation, improve metabolic health, and align their biology with the rhythms built into every cell. Links: Anders Varner on Instagram Doug Larson on Instagram Coach Travis Mash on Instagram

Shrug family this week on Barbell Shrug, Dr. Karen Esser is on the podcast, and we have a phenomenal conversation today about circadian rhythms and muscle tissue. Bananas. Had no idea this existed. Absolutely mind-boggling how connected our body is to the sun and the spinning of this big rock we all live on. And there's very few things that I hear in the strength. conditioning world or performance or health that catches my attention like talking to hurt it today. Legitimately, it's so many things move at the speed of technology and nobody ever just stops and go, well, wait a second, maybe we're still connected to this nature thing. It's the most important thing. But we just, we love to just move so fast without going,

uh, maybe the sun's important. Maybe the time of the day. Maybe. Maybe. how our body interacts with night and day and the sun and, ah, this is awesome. She's the coolest, mind-blowing stuff, and very, very happy we got to meet her. As always, get over to Rapid Health Report.com. As we're Dan Gardner and Dr. Randy Galvin doing a free lab lifestyle performance analysis, and you can access that at Rapid Health Report.com. Friends, let's get into the show. Welcome to Barb L Shrug, I'm Anders Warner, Doug Larson, Coach Travis, Travis, Smash,

Dr. Karen Esser. We're going to be talking about all kinds of cool stuff, but none. as important as the Jordan story you were about to tell us on super freak athletes because we just talked for 10 minutes about Chicago sports and how important they are to us. Take it away.

All right. So I had a student working in my lab many years ago and it turned out she taught swim class in the summer some of the parks or whatever and she had two of Michael Jordan's kids in her class and the one thing that she

noted with them. So they were teaching him. I don't know whether it was breaststroke or backstroke, but one of those strokes. And so they do that on the ground before they go into the water. And the one thing she noted is his kids had it like that. So the rest of the kids were kind of their arms were flailing in different directions and that kind of thing. But his kids, as soon as she sort of walked through what you're supposed to do, the, you know, sort of the coordination and the fact that, you know, they just would visualize it and then the body did what it was supposed to do was just off the charts. So the genetics were absolutely there.

Yeah. What would it be like to be Michael Jordan's kids, man? Like, what a thing to live up to. Even if you're the best athlete ever, that's a rough, that's a rough go. I'd not do it now. I think you just grow up knowing you're supposed to lose and everything. Like you never have an opportunity to win ever. So you just go second place, guys, we did it.

Congratulations. You got to be second place to dad. but you got to but dad expects you to be first place at everything else yeah my god his expectation has got to be super high but like the regression regression to the means or whatever so like if you got really amazing parents you're probably going to suck you know like instead of having like if you have two average a pretty good parents you'll be elite but like yeah but isn't that interesting on like an athletic side no one knows who jordan's kids are i do they weren't there was Yeah. I think I saw something with Bo Jackson.

I'd be, I say that line. They were pretty good, but like nothing like, yeah. I saw some or somebody interviewed Bo Jackson and asked him about his kids. And he was like, oh, my two boys, like, they don't have it. But the girl, she dominates. She got all of it. And she probably just whatever sport just walked kids for decades in sports until like college was over. Yeah. Yeah. Look at James. LeBron James's son is like nothing close to him. What is the perfect chemistry that allows that freak of a human and then to have to repeat it by mixing somebody else's genetics into the mix.

This sounds like a dangerous conversation. That's all I'm going to say right now. But you were saying, but speaking of like the actual man himself, like you were saying watching Jordan, you know, many years ago, growing up in. Chicago or just being in Chicago when he was like at his prime was just a phenomenal experience. Oh, it was. And I, you know, I mean, and like like most things, it's something to see it in person. I mean, it's, you know, I love, I can watch it on TV, but, but to, I don't know, it's just different, you know, and it's just, it was just, it was beautiful, honestly.

I mean, I think, you know, when you see that kind of athlete, you know, it's just like seeing a beautiful dancer. I mean, it's just the control, the movement, the, all of that to me is, you know, And then, you know, I mean, it's obviously a high skill set. It's real then. Impressive. Yeah. It's real then because you see it on TV, it can be, it's like, it's hard.

When you see it live, it's like real. You see the human. It's all different. My favorite part to think about those people is everybody that you're watching on the court at that moment in time is the best they've ever met at whatever they do until that exact moment where they're around all of the other people that are the, absolute best that they've ever met their entire life. And then there's one guy that, like, if there was a league above that would still be the best at the, at the All-Star League, whatever the best of the world already are. And you're like, just that far above and beyond is.

I love to hear like Reggie Miller and those other guys talk about Jordan. Like, they just talk about like how they did not want to talk junk to him because they're afraid to make you mad. Because if they made him mad, then there was no chance. But just to hear somebody who, everybody else, consider unbeatable. Say that about him. It's like, wow.

That's how good he was. No, I feel lucky to have had an opportunity to see him play. Watch this professional transition. Do you at University of Florida get to hang out with all the athletes that are also complete freaks? Oh, like the swim team and Katie Ledecki and those guys? I thought she was Stanford. Wait, did you? No, she's down here.

I mean, she's not in school. She's, you know, but she cranes down here with the guys. Caleb Dressel, those guys. See, that's the difference. The best girls in the world, they have to show up to guys practice and still hammer them, too. But, but yeah, I mean, so no, I don't. I'm over in the medical school. I mean, it's not that far, but it's, you know, these days, I mean, it's different worlds.

Yeah. It's too bad. Yeah. It's too bad those worlds aren't more connected, you know. Yeah, well, I do. I will say, I'm not going to name names, but I do. have a swimmer coming into my lab next semester. So I'm pretty excited about that. I enjoy having ethics in the lab. They know how to manage time really well. And they're driven. It'd be cool to have more

of that. Yeah. I'm sure. Yeah. Well, let's back up for a second. For all the people in the audience who may not be familiar with you. And who are you? And you know, you're a real scientist over here. What do you study? What's your lab all about? And what do you do at the University of Florida? Yeah. Hi. My name's Karen Esser. I'm a professor in the Department of Physiology and aging. I also serve as chair of the department at this point. I've been studying muscle my whole academic career. So, and I've been studied, so originally was, and very interested in adaptation in response to physical activity. So initially we studied muscle growth. So sort of fitting for Barb Bell shrugged. But then what I love about science is, you know, we

got this data back in the early 2000s, and there were these circadian clock genes in there, and I'm like, what the heck are these doing in here? And that sort of just, you know, curious and really kind of fascinated with the idea of this timer in cells. And so then have taken my lab off in that direction. We, you know, at some point, it's sort of overlaps. So, but, but the whole idea that that every cell in your body's got a clock in it and it keeps time and it affects the function of those cells and it can affect performance, it can affect health, that kind of thing. So, so yeah, it's kind of a wide mix. Aging's thrown in there.

Definitely exercise, exercise trainings in there as well. When I think about circadian rhythms and whatnot, I don't usually think about like one specific tissue, like muscle specific circadian rhythm. Like can you tell us more about that? What does that mean? and how does it play into sport performance and training? Yeah. Yes, it's super great.

So, okay, so there's, so, I mean, most people know about circadian rhythms. So you think about, you know, rest periods or sleep activity. You think about, you know, especially if you live in states where they do, you know, fallbacks, bring forward. You know, that period of time is, or is, is a, you know, where you don't feel great after traveling is a circadian disruption. So the basic idea here is that our cells have these little molecular timers, and it's not just brain, and it's not just light, that modifies these things. And what these timers do is they're playing a role in managing kind of the health, what we call, refer to as the homeostasis of the cell. So the ability of the cell to sense a signal or get stressed, but then deal with it, survive, and then sort of go back to, you know, a happy, healthy state. And it's, so the reality is your cells are doing slightly different things at different times a day.

So if we take our muscle, for example, so these timers are working in muscle so that during the sleep phase, for example, things that are more directed towards fuel storage, like glycogen storage, like identifying damaged proteins, repairing and replacing. So, you know, it sort of makes sense that when you're resting and your muscles are fairly quiet, that's when you want to fix stuff and you want to store stuff. And so then before you even wake up in the morning, what the clock inside the cell is doing is it's like, okay, let's get metabolic enzymes going. Let's start ramping them up before you get out of bed. So you don't have to think about this. This stuff just happens so that when you get out, you can go, you know, it's easier for you to get up and going, all right? And the fact is, so the discovery of the mechanism that underlies this timer was awarded the Nobel Prize in physiology or medicine in 2017. And historically, they just thought of this thing working only in the brain, right?

But it was, you know, early 2000s, people are like, God, these things are in all of ourselves. They're in liver. They're in muscle. They're in, you know, your colon. They're everywhere. And so why? Why are these here? And so there's been a lot of work over the last 10, 15 years to try to understand what these clocks are doing in different cells. How are they organized? And at the

end of the day, you know, I mean, I assume all you guys have experienced, you know, jet like, right? Dr. Andy Galpin here. As a listener of the show, you've probably heard us talking about the RTA program, which we're all incredibly proud of. It's a culmination of everything Dan Garland and I have learned over more than two decades of working with some of the world's most elite performers, award-winning athletes, billionaires, musicians, executives, and frankly, anyone who just wanted to be at their absolute best. Artae is not a normal coaching program. It's not just macros and a workout plan. It's not physique transformation and pre-imposed pictures. Artee is something completely different. Arate is incredibly comprehensive and designed to uncover your unique

molecular signature, find your performance anchors, and solve them permanently. You'll be working with not one person, but rather a full team of elite professionals, each with their own special expertise, to maximize precision, accuracy, and effectiveness of your analysis and optimization plan. Artee isn't about treating symptoms or quick fixes. It's about unlocking your full potential and looking, feeling, and performing at your absolute best, physically and mentally when the stakes are the highest. To learn more, visit Arteelab.com. That's A-R-E-T-E-Lab.com. That's A-R-E-T-E-E-Lab, dot com. Now, back to the show. I assume all you guys have experienced, you know, jet like, right? So if I go and I fly off and I'm fortunate enough to go, you know, to Rome, we're at six hours different, I'm going to feel a little

off. I mean, I'm not going to die. I'm not going to, but I'm just, you know, I'm not going to sleep as well, all those kinds of things. That's purely a circadian problem. It's your clocks in your brain are at one time zone, your guts in another one, your muscles are in another one. So they're out of what we call alignment. And so from a biomedical perspective, when your clocks get out of the line, you have higher circulating glucose, your blood pressure starts going up. You know, you start to see indices of sort of cardiometabolic disease, that kind of thing. So what we are learning is, you know, we have been going on about our lives not really realizing there's this clock system in there. and that, you know, we don't care.

We can get light any time. We can go eat any time. We can do whatever we want. But the reality is the offset of all those sort of lifestyle adventures can actually have negative impacts on our clock systems in our body. Now, from a sort of athlete performance perspective, there's quite a bit of data. Humans, men, women are stronger in the afternoon than in the morning. So if you go and you ask someone to do one one rep max, okay, and you do that at 8 o'clock in the morning, I mean, you can do it yourself too.

And then try it out at 4 to 5 in the afternoon. By and large, all of those people are going to be, you know, somewhere between 5 to 12% stronger in the afternoon. 100%. Which is a lot, right? And, you know, so they, you know, people have tried to figure out why, you know, is it the ability of the brain to do this? And there's no indication that it's that. Is it temperature? Are these different things? And so I don't have a great answer for you at this. I can't say like beyond a shadow of a doubt. But but there are some indications that actually the things inside the muscle can be, can work better in the afternoon than they can in the morning. And this is, this aligns with. when do you see Olympic records set? It's not 6 o'clock and more.

Later. Right? And so there's also indications that endurance is better in the afternoon as well. And so that's, you know, so there are some time of day variations. I mean, they're not huge. We're not talking fold differences,

but we're talking, you know, somewhere between 5% and 15% differences in a particular performance over time of day. And so if- That's huge for athletes. Yeah. huge. Yeah. And you talk about, let's say, college teams going, you know, so since our, our conferences are no longer restricted to regions, so you've got someone on the, you know, the Big Ten,

you know, flying all the way east to play somebody on the East Coast. I mean, they're going to, that, that first day is, that's, that's not good for their performance. They're not going to be at peak. All right. There's actually some really interesting papers. They've done, they've done, They've used major league baseball, you know, because there's metrics on everything. There's, you know, speed of the pitch, bat swing, all kinds of different things, beyond sort of wins and losses. And the data would argue that, let's say, if I'm the Dodgers, I travel to play the Mets, that first day that I get there, athlete performance in some parameters, not all, but some parameters is actually reduced. Now, let's say they're playing a three or four game series by the time they get to the end of the season. series, they're fine. But it's that first day that they tend to be less than optimal.

Wow. Now, what if you train early at 8 o'clock? You're forced to, which is sadly, like some colleges know that you don't have a choice. And so, and you make improvements in the morning, will those improvements then equate to like overall better than if I were to go max out at 4 o'clock? You see what I'm saying? Like, yeah. I don't have a study. Will it all shift forward? Yeah. So you're on to what I think is going on.

So we do have a study. Again, our athletes are furry. They're little mice. Okay. And so what we did, so with mice, you can, you know, we don't really have a good weightlifting, but we do have treadmill training, right? So if we give them a graded exercise test in their morning and then take them, let them recover and stuff and give it in the afternoon, just like humans, they have a much better performance in the afternoon than in the morning.

So what a postdoc in my lab did is he said just that. Okay, so I'm going to take you mice and I'm going to train you in the morning. I'm going to make you get up and get on the treadmill and train five days a week for six weeks, all right? And then I also had a group training in the afternoon. And they were trained. And so now this is, so this guy was sort of a real exercise physiologist. So he said, okay, performance in the morning is less than the afternoon. So I'm not going to equate them based on the same amount of treadmill work.

I'm going to make them train the same percent. So they're relative. So does that make sense, right? So if you can run six-minute mile, anyway, you got what I'm saying. Sorry, I shook my head because someone walked in my office and I was kicking them out. If I threw you, I was taking. No, I did see him and I'm just like, no, don't come in here. not no to you.

All right. So what he did is he set the relative intensity of the workload to same. So the morning runners are running at 70% of their max. And then the afternoon runners, which have a higher max, are still working at 70% of their max, all right? And so he's going to train them running five days a week. So at the end of three weeks, he tests them. And I'm using this because I'm going to become the graph here.

So the morning runners got better. They improved, which you expect. and the afternoon runners got better but to the same amount. So they still had a max performance that was different. All right. So he said, okay, I'm going to sort of increase your, well, I'm going to adjust your training. So you're now doing 70% of this new max. And I'm going to train you for three more weeks, right?

And so he did. And then at the end of six weeks, then we had the morning runners and we had the afternoon runners and they were exactly the same. All right. What that said to us is that so, and remember, I mean, so this is like, oh, great, I'm going to train in the morning because they trained at a lower absolute workload. But they got better. They actually, their performance adaptations were better than the afternoon trainers. Okay.

Got it. All right. Now, you know. I see what you're saying. They were able to travel with, I mean, they were able to train with less of an impact on their over, on their body. less. Well, yeah. I mean,

I don't. So the point with this story is that the, we, it took, I mean, so if we had stopped at three weeks, we wouldn't have seen a difference. I mean, that both would improve. So exercise will improve, no doubt. But the magnitude of the adaptation really became different for that morning training group between the three and the six week period. So we don't know exactly what's going on, but what we think is that what that's doing is it's adjusting that internal clock system because now your body's going, okay, I'm training at 8 o'clock in the morning. And so maybe the first week or two, it's like, okay, fine, but you're not going to stick with it, right? And so, but you keep sticking with it. So the hypothesis here is that the clock system is adjusting to that time. And so that adds an increased efficiency of the

adaptation by getting that shift in the clock system. Wow. Oh, man. You just, I mean, that's a big, because there's this big debate, like, you know, like, I'm sure you don't get on Twitter, but if you get on or X. I used to, but I actually have taken it off for various reasons. That's good. But people will debate that, um, the Smith coaches that, that train, you know, people say

6 a.m. 8 a.m., that they're wasting their time. But based on what you say, they might absolutely. not be, but oh, this is great. Okay, I can't wait to share this one. Awesome. Now, I mean, I, I, you know, I, like I said, this is, we're in the process of, we've got this manuscript submitted. So it's, it's undergoing peer review. But it's, the, I'm pretty, I, I was just really impressed with the data. I mean, it's just amazing. And so I, and there are, you know, the whole idea of time of training, obviously, has gotten kind of actively discussed, as you said.

Sure, all the time. Hold on, Ash, when do you train? When do I? Whenever I have, you know, like, sometimes early. But today I get to train in the evening. So, like, it depends on the day. Yeah, Doug, you're like a lot of time. So the question is more, what would you prefer?

Well, sorry. Sorry, I shouldn't know. No, hold on. Doug, you're a new trainer, right? Yeah, I typically like. train like right before dinner. Like it separates my work day. I just,

I was going straight from high school, straight from college, like same program. Like you go to school, you train, you go home, eat dinner and then like that, that's your day.

Like that routine has worked for me my entire life. So yeah, I like to work in the morning, train the afternoon and it's like a clean cut for family time and dinner and whatnot.

And then, you know, if I need to get extra work done, then I work early in the morning or later in the evening, usually later in the evening. Me too. I'm 645 on the button.

645 to 715. Mondays and Wednesday, spring training, long conditioning. I'm on the bike for, dude, you guys want to hear big numbers, by the way. A.m. you're saying. A.m. you're saying. A.m. Yeah. Up at 545, coffee, those things. My numbers, not absolute strength because it's too early to go and do crazy stuff like that. And it just don't have time to, like, warm up like that. But in a, like, linear progress. I never miss.

And all I have to do is like change if I if I start to stall, but week over week and it's been I've been doing the same workouts for almost two and a half years now and nothing changed in the morning once my body switched over and I love it now because I get I lift weights now that are like, uh, I don't need to warm up. I just go and it's like 85% of like it's heavy but feels good. for 8 to 12 and I don't need to think about it. But every week I get stronger.

I don't even know if I get stronger, but I get better. I do my morning. I have a 5.30 a.m. I do my cardio, I guess you would say, like in the morning. Like I have a sled. I do a sled, reverse hypers. Yeah. Some isometric work that helps my hips.

It's like my favorite. But like my big time training goes on. Either 8 a.m., which I hate or an evening. Yeah. One thing, I, and you may have some insight into this. Karen, when I switched from an afternoon to a morning trainer, it took me six straight weeks of unfortunate feeling to actually be able for my like system to flip. And then once it did, now I, you want me to wake up at five and go hunting.

Awesome. Like, I feel so good in the mornings. I actually have this like, like it just, I'm like a lot. Like my, whatever it is, when it flipped, I became a morning person like immediately. But it took me a full six weeks to actually be able to jump out of bed and go, go do strength training or conditioning, whatever it was. I mean, it makes a lot of sense to me. I mean, I think the, I mean, there's like most things with humans, there are genetic aspects. So, so we talk, you know, in the field, we talk a lot about the morning versus the afternoon, the larks versus

the owls. And there's a genetic underpinning to that. But that said, you know, what you talk about is just it takes time. So for you, it was six weeks. For somebody else, it may be eight weeks. For someone else, it could be five weeks. I don't know. But the way, and again, I want to be, I tend to be very careful. Because we don't know exactly why that is. But what I'm envisioning is there has to be some coordination. You know, I mean, your liver clock needs to know what your muscle clock's doing, needs to know what your heart clock's doing. And it all needs to coordinate with the brain. Because again, for you to feel good, for you to perform, the system itself as a network has to work together for the best performance. All right. And so I think it's just, you know,

when I think about, you know, so circadian rhythms are on literally everything on this planet. Okay, right? So it's in planets. It's in bacteria. It's in bugs. It's in birds. So these things are old. They've been around for, you know, virtually ever. And so, you know, I think that there is this, they are very entrainable from your environmental cues. And so in this case, your environmental cues are going to be your exercise. But, you know, when you get light exposure, you know, when you're eating.

So feeding time also is a modifier of some of these things. And for you guys with your training routines, I assume. you're very, you pay a lot of attention to all of those factors as well. Yeah. I even started Olympic lifting like two months ago and I thought that was going to be like speed and power and athleticism. Like it's one thing to just kind of like sit on a like a hammer strength machine and just knock out some chest, but to like snatch it six 45 in the morning and feel good. But even that stuff now, like once you're once it's been really interesting because it's all, It's been my first year of being a real morning person.

And when I own gyms, I would see the morning people like, you loony tunes, go to sleep. And of course, like the average age in that class is like 55. Like it's all the guys that have been playing business for a long time or like, they just got to get it done. But yeah, even adding Olympic lifting back into my program, like weights move, athletic, there's a tiny bit more of a warm up to what needs to be done. but I going to like the the part that you were talking about of like the the the inability to like lift at maximal weight I almost wish I could rewind the clock and go hey maybe your 23

year old self didn't need to max out six days a week like you didn't have to do all that maybe progression's even faster when you just do enough which is completely the opposite of what I felt for the first 20 years. Oh, I mean, you know, I don't know. I can't speak, because I'll be real honest. I don't like lifting weights. I know it's good for me and I know I'm a cardio person all all over the place. I was so your friend for a second. I'm sorry. I am so sorry. I'm so sorry. We do still like the cobs together though. I know. We still have that. I'm trying to be more like you now though. Like I'm trying to be more of the cardio person. So I think we share that.

Like, I'm being more and more. I think we've all added more cardio over the years. And if you want to talk about aging, both is important, right? Oh, yeah. For sure, for sure. For context with all this research, you're talking about morning versus afternoon. Like, if you're someone chasing a gold medal or world record, like maybe these distinctions really matter.

But if you're just a regular person, like, the most important thing is that you just find time to get it in and you can, you can do it consistently. Day after day, week after week, month after month, you're out. after year and like you can you just you do it at all is the most important thing at the end of the day for the for the most normal people sure you know anybody on here is normal here but that's yes so i certainly not no i would say yeah i mean i think the the most important stuff is be be active i mean for anybody that has i mean if you're thinking about yeah i mean if you're an elite athlete i mean this is why the athletes go over to wherever they're going to compete ahead of time so they can you know i mean if it's jet lag or feeding

cycles or whatever, you just want to get into that time zone. But even as you're talking about, you know, if there's that part of you that wants to see your performance improve, then there are things like paying attention to when you're training to support the potential for seeing that, right? So as, you know, if you're talking about, okay, one morning I'm at 8 a.m., the next time I'm at 8 p.m. Then I'm, you know, if you're just sort of randomly switching around, I, again, the hypothesis would be the, the trajectory on your improve, you'll have improvements, but the trajectory will be less because you're flipping the time all over there again. So if you can do the time and stick with it, that's going to be better for you. Is there like a, uh, like,

the body is kind of like always seeking some sort of homeostasis for stability to grow until that stability becomes a deterrent because there's not enough like volatility in the system to adapt to? Is that is that also with the clock? I mean, yeah. So, I mean, I mean, to me, homeostasis is key, right? I mean, that's, that defines the ability of your cell or your tissue, your system does sort of like, and I think of it more from a health perspective that, you know, you get the flu, you get broken leg, that your body can handle that. it repairs itself and you come back to where you were. So you don't come back to less to, but you come back to where you were.

So in terms of an exercise response, I think, you know, you may have something there. It's the idea is you have these, obviously exercise disrupts homestasis a lot. And so, and in fact, you want to, you know, one would argue, and maybe they do, that you want to make sure you're back to homeostasis before you go into that next bout. Is it useful at all to have exercise, not really recover, then go hit it again? That could be less ideal in terms of, you know, the adaptation, the response, the growth. I don't know if that answered what you're asking. I couldn't, you were making faces again, so I just.

I saw talking to somebody too. There's anecdotally. I live on a farm, so there's a lot of people around here just doing stuff. I don't even know who they are. That one was my stepdad. He likes to come in and just walk around. Oh, yeah, of course. I just wanted to agree with her on one thing.

Upstate, when I was there, the people who trained early in the morning, there was a 530 a.m. group. And, like, I tried it once and quit right away. But I could, but, like, those guys, you know, even though they look miserable, when we went to, you know, when it was maxed out time, as a group, they seem to do the best when it came to improvement. And so your hypothesis, I would say the anecdotal evidence there agreed with you for four years. Over and over, the early groups seemed to when it came to max out time, because then we would max out at the same time. We would all go to the evening. And then they would have this big bounce up.

There might be an element there of like camaraderie where every gym have ever been at. that the 530 crew it's the same people it's the same people every day so they're kind of like a little team and so they train every day and if they're all squatting and maxing out every day it's like there there's this there's this team element that is not present at other times of the day yeah they can keep it he's like I'm not going not doing it I got my own friends I tried it I tried it once it was the most miserable yeah I mean I think you know well so when you think about these you know sort of so I'm I'm looking at you Travis and I'm saying okay so maybe you're more of an evening person. So morning for you, early morning for you, maybe more like eight to nine

rather than, you know, six. It really is. Seven, right? So, so you just sort of have to, you know, that there, I mean, I mean, if you want to do an experiment for me, give that a try and try, try your, try your 8 a.m. training. See how that goes and see how your progression goes. I do, at 8 o'clock, I can do really, I can do not as good at four, but I can do it. enjoy it and like it's fine. Okay. But then when I go, then when, if I have a moment to go to the evening to like to hit a bigger number, it's that normally is a really big like jump up.

So you experience that a lot, huh? Yeah. I do. Yeah, I normally have to train eight. And so every once in a while like today I get to go and I'm excited. I get to train the evening. But normally eight o'clock is my time. Good.

Yeah. Five a. Real quick, earlier, you mentioned how, you know, different tissues might have different circadian clocks or circadian rhythms. Like, how would muscle tissue be off or misaligned from liver tissue or brain tissue or any other example that makes sense here? Or do I have a wrong what I'm saying? No, no, no, no, you're right on.

So I, so the reality is the clock itself, the sort of the components of the clock are exactly the same between the liver or the muscle of the heart, you know, the fat cells have them. Every cell has them. Where the best recognized problem with this is actually people that eat at night. So it turns out what time you eat can be, can tell the clocks in your peripheral tissues like liver, like muscle, those kinds of tissues that, so if I spend more my time eating at night, then the clocks in my periphery are going to shift just like we were talking about morning. exercise, they're going to start shifting backwards, okay? So the other direction. Now, the problem is

the brain doesn't respond to this at all. So the central clock or the master clock in the hypothalamist does only response to sort of when it gets its light cues. So if I eat at nighttime, the brain's like, I don't care. And so what you end up having are some of the organs in your, you know, your body are sort of shifted with that night eating. Your brain still is tied into when you see, light and dark. So you actually create sort of a jet lag effect without traveling. So this is where, you know, when I talk to the students sometime, it's like, yeah, you too can experience jet lag without going anywhere. You just have to offset your light exposure, your feeding. And this could happen with exercise as well. So basically, you know, you sort of think about something like feeding and

the response of insulin and the ability of insulin to help get glucose into your cells, that actually shows a time of day variation, right? So it's not the same all the time. And this can become a problem when, let's say, your pancreas is like, oh, I'm releasing insulin and the muscle's like, nah, I don't really want to bother with it. It's the wrong time for me. And, and, you know, again, this is just sort of a very simplistic idea, but this is how you get sort of pre-diabetes. when your clocks are disrupted. So your pancreas is doing one thing, your guts doing, your brain's doing something else, and your muscles just like, nah, wrong time.

Because muscles stores, you know, most of the glucose. And so if it's not willing to participate in this, it creates a problem. So, so this is maybe completely off, but that just blew my mind a little bit that the circadian, the clocks inside your body not talking to each other creates the stress that's going to also be linked to diabetes. It's like nighttime eating is a big, no, no. It's a big, yeah. Yeah. And I'm not even going to talk about weight gain or any of that, but just the metabolic stressors.

And what it does. Yeah. Like, I'm never, I'm never hungry in the morning. I'm always hungry at nighttime. I eat dinner and then I eat dinner again and again. well you've been doing a long time I mean there's sure

I'm like I'm like you brother like nighttime all the way like I'd be tired all day long and then nine o'clock hits and I'm like wide awake and I'm like dude I keep going all night I know that's like when we hang out

we're like on the same page like all night and I'd be asleep so I mean not me man no wait so for from like the most practical standpoint here. What is like the ideal kind of day with waking, eating, training, all the things in your mind, as far as keeping like maximal alignment between all the different organ systems in the body?

Based on your furry people. I'm sorry. What's that? It's based on the mice, the furry people. The furry people. Yeah. I mean, actually, there's, there is quite a bit of data with humans on this one. But I'd say, I mean, the one thing is, you know, when you think, when you talk about the clock system, This is not a precision clock. So it's not like it's like, okay, it's 10.35, I need to do this. So I think, I think of these behaviors like wake up, go to sleep, when you eat, when you exercise. You know, I think of them in sort of three to four hour chunks of time kind of thing. I mean, eating, I would say, again, I mean, when you guys are doing something, I mean, it depends on whether you're doing really extreme training.

because with a high level of, you know, who's going to tell Michael Phelps when he should eat? No, not me. You know, when you're going through the calories he goes through. But I, you know, for the sort of average person, I think thinking about, you know, a 10-hour window sort of, you know, whenever you have your breakfast, try to get most of your food in in that 10 hours. It turns out when they did some study with a group of people, it's like Americans eat over like a 14 to 15 hours. window. That's probably, I mean, I don't know, again, unless you're talking to somebody with extreme, with, you know, heavy duty training, I don't think that's probably a good idea.

I agree. Yeah. And so. Yeah. I mean, in terms of the sleep wake cycle, I think you really, you know, it's unless you do what, what Andrews did and sort of get himself flipped, generally, like I said, people have a genetic preference. And so as best, you can work with your preferences, it's going to be, life will be a bit easier. So I have always, as far as I can remember, been a morning person. And, you know, I can, there was, when I was a graduate student, I ran, I did a few marathons. So I did a lot of run training and, you know, that kind of thing. And damn, you know, I could run it three in the afternoon, but I hated it.

I felt like crap the whole run. And, you know, I spent all this time, again, I didn't study circadian back then, spent all this time thinking about, you know, when do I eat? What do I eat? What's wrong with this? And, and now it's just like, well, hell, okay. I just, it was, it was just not going to be my time. And so, I think working with your body, when does you prefer to run? When do you prefer to run? Oh, morning. Like, what time? Oh, well, I actually, so I do the, you know, five, so you get to have the coffee, then, then let's go. I mean, when I was in graduate school, I rolled out of bed. I didn't even have. coffee. I just went rolled right onto the road.

The morning is life changing. I agree with you on cardio. Like, I love doing cardiovascular work. Even my, like, you know, I do a lot of circuit training in the morning, but like, I love doing that. I just don't like lifting heavy in the morning. Okay. It just seems like pure hell to me.

Here's the problem, MASH. When you say lifting heavy, it's a lot, dude. It's not. And it's getting more and more. Yeah. It's like, even if it hurts. Even if you were doing like 80% deadlifts, you got to do 1.35, then 225, then 315, then 405, and finally at 495, you get to go to work. It's an absurd amount of weight that you have to lift to actually feel something.

Us normal folk can just lean over 275, feel good about ourselves, and go back home. You complicated the process being too big. I'm trying to get in shape again, too. It's way, yeah, I'm way past. Oh, it's hard. Yeah. Aging doesn't help any of this. When he says heavy, it's just different.

Yeah, but. I agree with you. Like, if you're just trying to get a good sweat in and like, again, you're not like, you're not training for marathons. You're trying to hit PRs. Like, you're just trying to get, you know, 30 minutes of movement in. You're going to wake up and you're going to feel great the rest of the day. Exactly.

That's my point. It makes it. It's like coffee. Like, I didn't realize just how much it made you. And everything the rest of the day is better. Like, I learned better. Like, I love to, like, train 30 minutes hard. Then go, like, study something. And, like, I retain all of it.

I wish I had known this while I was in school. I have a completely out there question to ask you, since we're talking about circadian rhythms and how important sun is to our body. if you are wearing like lots of sunscreen, which I haven't done in over a decade, sunglasses, does that affect these circadian rhythms and that you're blocking?

I was so hoping you were going to say yes because in my brain, and I'm going to act like you didn't answer no and keep telling people that they shouldn't wear those things. I disagree with you. I just say I can't throw all over. No, I mean, no, yeah. So, I mean, the skin cells

do have clocks for sure. But I mean, the skin that gets, I mean, the skin that's on the outside, outside is not really alive. I mean, you're, these are, all right. So, I mean, well, I shouldn't say it like that. But I, your eyeballs, they're like the, the, the absorbers of, they're like a muscle that needs to contract and relax. And in fact, well, in, in fact, I actually, I should retract everything I just said. I knew it. Did you put the show? Not, no, not everything. Not everything. I was just talking about the skin cells. Damn it. Don't mislead anybody.

But I, but it, you know, so in the skin cells, what they see is, what the clock's regulating is DNA damage repair. And so there are time of days your skin cells have more apparatus or more or more of the things needed to both sense and repair, demon and damage, which is, guess what, light induced. and so so the clock is so what the clock is doing in those skin cells is going to be besides keeping time it's going to be different than what it's doing in the muscle cells so that's the i mean it's the same mechanism but it's evolved to do different functions and different cell types i can't believe i've never heard of this i mean i mean it's amazing yeah i'm a master's in excess physiology we never once talked oh no they did no they actually i was uh i can't or one of my colleagues is putting something together.

And so they are just starting to put some of this into the exercise physical. They need to put this in. This is great. Yeah. You mentioned at the beginning of this that you're not working with the athletes, but you're in the medical side of this. As far as where this would show up, you mentioned kind of like being pre-diabetic as something when the clocks are all out of sync.

How far or like what other call them like simple? show up when you see this. Like on a medical side, I don't really even know what the question is outside of like pre-diabetes. Is that the downrange effect, like side effect of this? Or like, is it cancer? How do you? I want to know about aging. Oh, God.

Well, so, yeah. I don't know if you guys have a hard stop at too. But I think, so you're opening a Pandora's box here. So the most well known, you know, so if you take shift workers, so shift workers are a great example of everyday living people who are chronically messing up their clock system, right? Yeah. And so, you know, there's higher probability of metabolic disease, higher probability of cardiovascular disease, higher probability of cancer, higher probability of cancers, all these chronic diseases. But which one, second or third shift? Like, which is worse?

Well, I mean, so again, so the, in theory, if you worked, if you lived and worked third shift, okay, steady. So the problem is people work a shift, then they go back living with their family on a regular day. Then they go back to another shift. So it's this flip-off. It's a flip-flopping. And so something like swing shift is just like the absolute worst, right? Got it, got it. And so, so the Center for Disease Control years ago had made shift work a cancer risk.

So you have higher probability of these diseases when you're undergoing this sort of, you're sort of chronically messing with your circadian system. And I mean, there, and I, you know, there are things like, you know, people that work night shifts will have food preferences that are different, usually not things that are terribly healthy, high sugar, high fat, that kind of thing. So there's everything from what kind of food do you eat and when do you eat, but to just the intrinsic biochemistry and metabolism of the body that get messed up with this kind of thing. Mental health care.

Why does third shift? Oh, okay. That's the first question. Night one. Why does third shift people crave more sugar? I don't know. I mean, there's, I know. I know people have worked on this.

I mean, so the, you know, there are circuits in the brain that I don't know. Yeah. I know when I wake up. I mean, I've worked shift. I've worked that third shift. When I wake up at midnight, I crave sugar. And like, I try. I've been really good about not doing it lately.

But, man, I just want to like eat strong sweet. What about mental health? Like, what causes that? Well, again, I mean, this is, I'm a muscle person. But I, but I, so I'm just what I'm sure. sharing with you is that there's no doubt that circadian disruption will have issues in terms of depression. That's the most common, I think. Paul, because you're awake all night staring at your damn phone, putting sunlight in your

eyes, read Twitter and TikTok, people being angry telling you you're right about everything and why the world's all messed up. Then you have to live with that forever with no sleep. Well, no sleep is, so sleep and circadian rhythms are related, but not overlapping, right? Right. So sleep's absolutely important and fundamentally important. Your clock's going to be more about when you go to sleep, when you wake up kind of thing. And so if you have sleep issues, you usually have circadian issues. If you have circadian issues, you're going to have sleep issues for sure. This has been phenomenal.

There's so many times I feel like I hear something in the fitness after all of these years where I'm like, holy crap. This is like wildly interesting. You did it today. High five to you and your Cubs. Go Cubs. Go Cubs. Where can people learn more and find your research, all the things? So, I mean, you can just Google me and they'll be, you know, you can find papers we've published and things we've done.

Yeah, it's easiest email me. I do actually respond to emails in general. There you go. Coach Travis Mash. Nationallead.com. That was fascinating. It's been a long time since I've been something fascinating.

I'm going to go on a super deep dive, but thank you. Going to the medical side, next time we talk to you, sounds really awesome. We got to get it back on. Happy to. This has been great.

Blood pressure. Yeah. Cholesterol. All kinds of things. Oh, yeah. When do you take your statin drugs for all those cholesterol people? You should take it at night.

There's time of day differences. guess. There you go. All right. That's a cliffhanger. That's all right. You can find me on Instagram, Douglasie Larson.

Yo, appreciate you being here. I'll pair it with these guys said. You taught me many new things, which is exactly why we're here. So thank you for coming on. Okay. Well, thank you. It's been a real pleasure.

And go Gators. I'm Anders. I'm Anders. I'm Anders Warner at Anders-Barrner. And we are Barbelsrug to Barbell-Srug. And make sure you're to visit rapid healthreport. That's where Dan Garner. Dr. Andy Galpin,

doing a free lab lifestyle. and performance analysis. You can access that at rapidhealthreport.com. Friends, we guys. We'll see you guys next week.