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When I first heard about heart rate variability (HRV), I was expecting it to be yet another lame “biohacking” gimmick.

The pitch is by analyzing the rhythm of your heart beat with special software, you can gauge how stressed your body is and adjust accordingly.

For instance, if you wake up and your HRV indicates your body is overstressed, you may want to save the heavy squat or deadlift workout for another day, or if your HRV has been off for several days in a row, it might be time to deload or take a diet break or get a little more sleep.

Again, it sounds like very fake news, but lo and behold, there’s good evidence of its validity. This is why high-level athletes have been using it for years, and now that the technology has become cheaper, it’s becoming more popular among recreational athletes too. 

In this episode with HRV expert Dr. Mike Nelson, you’re going to get a crash course in HRV, including how to measure and track your HRV, what lifestyle factors affect it most, how to use it to regulate your training, and more.

Let’s dive in.


5:13 – What is heart rate variability? 

10:06 – What are the differences between average heart rate and heart rate variability?

15:07 – What do higher and lower levels of heart rate variability indicate?

17:26 – Why is variability affected by the physiology?

25:08 – What affects heart rate variability? 

37:36 – Does diet affect heart rate variability? Does caffeine affect HRV as well? 

40:02 – How does diet affect heart rate variability? 

58:07 – How much does training intensity affect heart rate variability? 

01:15:24 – Is there a specific range where you you tell the client to slow down?

01:30:35 – How does nutrition affect heart rate variability?

01:43:04 – How can someone track their heart rate variability? 

Mentioned on the show: 

Dr. Mike Nelson’s Website

Shop Legion Supplements Here

What did you think of this episode? Have anything else to share? Let me know in the comments below!


Mike: Hey, Mike here. And if you like what I’m doing here on the podcast and elsewhere, and if you want to help me help more people get into the best shape of their lives, please do consider supporting my sports nutrition company, Legion Athletics, which produces 100 percent natural evidence based health and fitness supplements, including protein powders and protein bars, pre workout and post workout supplements, fat burners, multivitamins, joint support, and.

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So again, if you appreciate my work and if you want to see more of it, please do consider supporting me so I can keep doing what I love, like producing podcasts like this. Hey, Mike Matthews here and welcome to another episode of muscle for life. This time around, we’re going to be talking about heart rate variability, or just HRV as it’s often referred to. Now when I first heard about this, I was expecting it to be just another lame biohacking gimmick. The pitch, if you haven’t heard it, is that by analyzing the rhythm of your heartbeat with special software, You can gauge how stressed your body is and then you can adjust accordingly.

So for example, if you wake up in the morning and your HRV indicates that your body is overstressed, you may want to save the heavy squat or the heavy deadlift workout for another day, or if your HRV has been off for several days in a row, it might be time to deload, or to take a diet break if you’re cutting, or get a bit more sleep, or eat a bit more food.

Now again, that sounds unlikely. To pan out, but lo and behold, there’s actually good evidence supporting the use of HRV. And this is why high level athletes have been using it for quite some time now for years. And now that the technology has become cheaper, it’s becoming more common among recreational athletes, including weightlifters as well.

And in this episode with HRV expert, Dr. Mike Nelson, you’re going to get a. crash course in HRV, including how to correctly measure and track your HRV because there are several options out there and some are better than others. What lifestyle factors affect HRV the most, how to use HRV to regulate your training, and more.

I hope you enjoy this interview. Here it is. Hey, Mike, thanks for taking the time to be my guest today.

Dr. Michael: Yeah. Thank you very much for having me on here. I really appreciate it.

Mike: Yeah. I’m excited for today’s talk because it is something that is fairly mainstream that I haven’t written or spoken about at all, I think, which is hard.

To do it’s hard to find something that I haven’t at least touched on and that is heart rate variability. And I guess the reason why is I haven’t looked into it all that much myself. I did play around with it a bit. I want to say a year, year and a half ago, did just did some cursory research, read some basic stuff about it.

Okay. I understand the theory. That’s interesting. And found that my HRV was more or less always in the same range, regardless of whether I slept better or worse or trained harder or, or not so hard. And I was like, oh, okay, anyway, moving on, which is not to say it’s not useful. I just dabbled in it. I didn’t make a real experiment of it and who introduced me.

I think it was, I think Mike Ruscio, right? Who introduced us and then HRV came. I was like, oh, that’s perfect topic and something that you know a lot about. So here we are.

Dr. Michael: Out of curiosity, at the risk of derailing everything, what HRV system did you use?

Mike: That’s a good question. So I had a chest strap monitor.

I don’t remember the brand. I could probably, maybe when you’re talking, I’ll pull up on Amazon. I think I bought it on Amazon and, and I had an app, my brain saying elite HRV, is that even an app? I actually don’t even know. It was an Android app.

Dr. Michael: Oh, gotcha. Yeah. They had the one in the early Android ones and.

Yeah, we’ll get into position and some other stuff on that too, because there are some things that obviously can affect it and not seeing a change is interesting, so it could be a couple things. So, yeah.

Mike: I guess there were slight differences, but it was usually around the same score. I want to say, oh, again, it was a bit ago.

I might’ve seen something in the fifties, uh, thought that I remember that standing I was, I was kind of interesting. But I think it was generally in the seventies to eighties. If that makes any sense again, it was a while ago.

Dr. Michael: And they just kind of have their own little scale.

Mike: Anyways, we can get to that, I guess, when we get there in the discussion, but I think we should start with just a simple explanation of what this is.

What is heart rate variability?

Dr. Michael: Yeah. So the more technical definition is a lot of people are used to looking at what is your average heart rate, right? Especially now with, you know, watches, I have a Garmin watch, Apple watch, whatever, take your pick. Or even if you can debate accuracy about it, but treadmills will give you a resting heart rate and exercise heart rate and all that kind of stuff.

Your phone too, right? I mean, you put your finger up to the light, right? Yeah. Your phone will give you one. So most people are used to seeing average heart rate. So when we talk about heart rate variability, we’re actually talking about how much your heart rate varies just a little bit from one beat to the next or what’s called the variability analysis.

And when we do this kind of fancy math, this variability analysis, which there’s a bunch of different ways to do it, and we’re not going to bore people with the discussion about nonlinear, linear math, tight domain, blah, blah, blah. It gives us a marker of the status of your autonomic nervous system. So your listeners are probably familiar with that.

It has two branches. One is the parasympathetic branch, and one is the sympathetic branch. So I always tell clients it’s, imagine the parasympathetic branch is like the brake on your car. I push down harder. On the brake pedal, I increase the force of the brake, and the car slows down. So paradoxically, I increase something, which is called vagal tone.

I’ve increased parasympathetic tone, just like stepping on the brake on my car. My heart rate is gonna go down. And my HRV will actually reflect a change in that. So the parasympathetic nervous system is primarily your rest and digest and recovery branch of the nervous system. On the other side, we have the sympathetic nervous system, which is like the gas pedal in the car.

If I step down harder on it, it’s going to go faster. I do things to increase sympathetic tone, my heart rate is going to speed up and some other changes are going to happen also. So the nice part about heart rate variability is it’s a pretty good marker for the status of where that autonomic nervous system is.

How much am I parasympathetic in relation to how much am I sympathetic. And it’s more like a dimmer switch on a light. And not necessarily an on or off switch. So you always have some parasympathetic, you always have some sympathetic that’s more like a ratio of the two. And when we look at HRV, we do that, let’s say, first thing in the morning.

That gives us status of where your autonomic nervous system is. And obviously, that can be changed by a whole bunch of things be changed by sleep, nutrition, practical discussion is training, even different types of training, aerobic, anaerobic, different types of intervals, etc. And the end goal is.

Initially was proposed to predict performance, which we can discuss, and the data on that is kind of split at best. But what I found it was most useful for was having a marker of the level of stress that a client was under. Most of my clients, especially now, are all online clients. So I don’t really have the luxury of seeing them, you know, walk into a gym like I did in the past.

I don’t get to watch their movement. I don’t get to watch their breathing, their interaction, their eye movements, all the other stuff that So, yeah. You know, a lot of coaches and trainers do almost unconsciously. To kind of figure out where the status is and where they’re at, obviously watching their performance bar execution, speed, velocity, things of that nature.

I don’t really have the luxury of getting all of those things, unless you want to get pretty complicated with some other measuring devices, but I can have them sit down and do this HRV measurement in the morning. Some devices will run overnight, some will take two to four minutes to run in the morning.

And I can have a snapshot of where their autonomic nervous system is at that point in time. And that gives me some idea of how their body is responding to all the different stimulation going on. And based on that, we can decide, eh, you know, maybe we’ll go with what we have planned today. Maybe we’ll make some changes and maybe we’ll run it for, you know, a couple of weeks to get a good baseline and there’s different variation and permutations.

You can run from there. But what I really like is that it’s a relatively easy thing to get. It’s non invasive. doesn’t cost any money. Each time you run it, I don’t need a, you know, saliva cortisol sample to be run to a lab to see where you’re at. I can get a very good idea of the status of your nervous system just by doing this measurement once a day, usually first thing in the morning.

Mike: And I may have missed it but did you clarify the difference between just heart rate or average rate variability? Because many people they don’t that gets mixed up.

Dr. Michael: Yep. So it definitely gets confusing. So when we look at heart rate variability, so how this works is and how I got into it initially was years ago.

I did my undergrad. I did a master’s in mechanical engineering. I spent about another five years in PhD program in biomedical engineering at the University of Minnesota. I ended up dropping out of that program entirely because I literally did not want to do any more math. I had a minor in math. I’d taken three more math classes, you know, beyond calc four, which I didn’t even think there was math that existed beyond calculus four.

And I’m like, man, I don’t want to do this anymore. So I ended up pulling the plug on that dropped out, I go over to the physiology department that fall and I literally sit down for like the first meeting we have my new advisor in the exercise physiology departments like, Hey, we got two new projects, uh, one’s on heart rate variability and one’s on metabolic flexibility.

And they both involve math and he’s looking around the table and, you know, most people, even at a high level and exercise fizz, you know, math, isn’t something that you take a lot of. It’s just not part of the curriculum sub areas there are, but in general, it’s, it’s not really a huge requirement. And he looks at me and he’s like, Hey, you.

Math boy, whatever your name is, it’s like, these are your projects. Now that’s what I’m trying to escape. This shitting me. Like I come all the way over here. I was trying to avoid math and now I get more math. And so at the time we had to bring people into the lab. We had bought this equipment used, which costs us about 12 grand to get.

And we had to run these measurements. We had to run them through two systems. I had to create a custom MATLAB code to do this and drop it into kubios, a lot of monkey motion. And even if you had all that, you had someone to do that, it wasn’t super useful because you had to come into a lab in order to get a measurement done.

And with HRV, you kind of want to know, well, how does it change from one day to the next? We were doing an intervention study related to energy drinks and some other stuff. And so fast forward a couple of years after that, one of the first companies, iFleet came out with a system to just run it on your smartphone.

I think the app at that time was 8, which is I think the same price it is now. And it runs off of a Bluetooth heart rate strap. So you would get up in the morning, you would turn on the app, you would hook up this heart rate strap and the app, because it’s basically a smart computer will crunch all of the data and all of the numbers and everything in the background for you.

So what that’s actually doing is it’s taking about a 55 second period and it’s looking at one beat to the next beat. So if we have one person sitting in a chair and for the sake of simplicity let’s just look at it in terms of beats per minute and we have super accurate equipment and we’re measuring the resting heart rate just seated in a chair.

We’re watching the numbers go by on the screen as it records. Oh, it’s 65. 1. Oh, it’s 66. 7. Ooh, 68. 1, 65. 4, 64. 9. There’s a little bit of this variation from one beat to the next compared to someone who’s 65. 2, 65. 5, 64. 9, right? They’re not having as much of that little variation from one, what’s called R wave to the next R wave.

So the electrical contraction of the ventricle. Because that’s what’s easiest to pick up on the EKG and for the algorithms to pick up. So what that tells us then is that little bit of variation from one R wave to the next. That gives us information about the status of the autonomic nervous system. So if we have someone we measure just the average heart rate, like old school numbers that are easy to get, that gives us some information, right?

We know that if you have a higher heart rate, probably have some more sympathetic output, right? You’re jamming down on that gas pedal of the car a little harder, or you’ve also pulled off of the brake. But it doesn’t tell us anything more beyond that. It’s it’s very much a crude marker. With HRV, because we’re looking at that fine scale variability, that little bit of difference from one hour wave to the next, When we run that variability analysis, kind of that next level down of math, we can get a much more better picture of the status of that autonomic nervous system because remember both branches are kind of running all of the time.

So it’d be like a race car driver, a rally car driver driving around with, you know, one foot on the brake and one foot on the gas. By doing that, I can get a little bit different combinations. Even though the speed of the car, if I were to measure it, may be the same. And how you get that average heart rate, that’s what HRV will tell you.

Kind of what sort of percentage of that is more parasympathetic and what is more on the sympathetic side.

Mike: And what do high and or higher and lower levels of variability indicate? You had mentioned it in terms of nervous system activity, but maybe also just in terms of does it mean that your body is under more stress?

Does it mean you are maybe not recovering from your workouts? Again, these are just questions that I’m asked about it, so I’m just passing them along. .

Dr. Michael: Yeah. Yeah, so as the variability. gets less. That is an indicator that your body has a higher sympathetic tone or is in a more stressed situation. If you go back in time, there was an old Chinese proverb that said, you know, if you listen to his heartbeat and it sounds like a metronome, you know, death is very close, right?

If you have that metronomic that you’re hitting that exact same heart rate every single beat. You have very, very little fine scale variability. You’re under very high levels of sympathetic stress. And we know from studies that for, you know, mortality, that’s not very good, right? Your risk of dying goes up dramatically.

Mike: Which sounds kind of counterintuitive because we always think of the heart of this machine that runs, uh, very precisely, which it does, but this is where less Precision per se is a good indicator and or at least conformity is a good indicator and exact repetition is a bad indicator.

Dr. Michael: Yeah, so I would even go farther and argue that almost all physiologic systems we’ve looked at have some level of fine scale variability.

And every time that that fine scale variability is lost, you’re kind of going in the wrong direction. Whether we watch somebody’s sway, we watch gait, uh, there’s some stuff with breathing mechanics. I was doing some stuff looking at fuel usage, how micro changes in fat and carbohydrate use via metabolic cart.

Maybe a marker for metabolic flexibility. So my PhD was looking at basically fine scale variability across physiologic systems. So can we use these fine little changes to non invasively extract some information about the system, knowing that in the case of heart rate, as it becomes more metronome like, that is a movement in the wrong direction.

Mike: And why is that physiologically without getting too deep into the weeds? I’m just curious.

Dr. Michael: Yeah. So if we take a short trip down the rabbit hole and you’re like, well, wait a minute. Why the, why, how the hell does that even happen? Right? So if we set aside that fine scale variability is a good thing. If we look at HRV and we go, okay, what are we actually trying to measure?

Like, yeah, yeah, yeah. You said we’re measuring the R waves, right? So everyone’s seeing their EKG. We see the big spiky pointy thing, which is the R wave, which is a representation of the QRS complex. which is looking at electrical movement through the ventricle, the bottom chambers of the heart. It’s much easier to see than the P wave, which is the atrial or the top chambers, because the ventricle is much bigger.

We have longer time that the current, the electricity has to pass through. So when we look at it on something like an EKG, it’s easier to see. For HRV, we actually want to know what’s going on in the atrium. And specifically, we want to know what’s going on with something called the sinoatrial node. So there’s a little group of cells in the atrium, in the top chamber of the heart, and if we pull these cells out and we put them in a petri dish and we have them beat on their own, they’ll actually go at a rate of around 100, right?

These cells are programmed to do what’s called a depolarization at a rate of 100. If we pull cells out of the very bottom part of the ventricle, Those cells will spontaneously go off at a rate of around 40, right? So just think of it as your heart always has these kind of cells as a backup system.

Because if you lose your heart, right, don’t have a heartbeat, a lot of bad stuff’s going to happen, you know, not very good for your survival. But most people sitting around, even at rest, even if they haven’t been training, they’re, you know, kind of a little bit deconditioned, the resting heart rate’s not 100, right?

It’s, you know, 60, 70, you know, somewhere around there. So most of the time, what’s happening is you’re under what’s called a vagal stimulation, right? So most people now may have heard of the vagal nerve, which is very popular, kind of called the wandering nerve, and it comes into the SA node. And when it stimulates the SA node, just like pushing down harder on that brake of the car, it’s actually decreasing heart rate.

So most of the time when you’re at rest, you’re under some kind of vagal stimulation. You’re driving your car around, pushing down on the brake of the car to slow it down. And the more vagal stimulation that we have, that is a marker for parasympathetic activation. Our heart rate is going to go down and our variability, our fine scale variability will actually go up.

So if you think back and you go, okay, so this thing literally has like a one cell intervention. The vagal nerve is able to fine tune the heart within milliseconds. So when we look at an EKG, we measure the distance from one R wave to the next. That’s usually done in milliseconds. You divide through by 60, 000, you get your beats per minute.

Is the R wave the large peak or no? Is that the P wave? Yep, the R wave is the big large peak. And the reason they pick that is because it’s It’s just easy to pick up on most equipment. The P wave is really small and really hard to get, so you end up with a whole bunch of noise and a bunch of other issues.

As long as they’ve got normal cardiac physiology, it doesn’t matter which one you pick, they’re both going to give you the same level of information. If you start getting into pathologies and stuff like that, you can see really wonky HRV, just because you’re kind of not measuring the thing you want to.

So when we get these R waves, And you’re like, okay, so we can see these millisecond difference from one R wave to the next. So the hard part with HRV is you have to be accurate picking off these R waves literally within a few milliseconds, because otherwise the information you’re trying to extract is just going to get lost in a bunch of noise, right?

And that’s why the system that you use, which we’ll get into, does matter, because we need to be pretty accurate with those.

Mike: That’s just because of the distinctions are that slight, right? I mean, that is the level of variability. We’re not, it’s not changing by several beats or something.

Dr. Michael: No, it’s not seconds. It’s milliseconds. And that’s why it made, you know, getting consumer grade tech a little bit harder, because if you get noise, you get other things that show up, you need something to measure these things pretty accurately. So now if we back up and we go, okay, wait a minute, wait a minute, what’s going on with the sympathetic system, right?

Because I said there’s two branches. There’s the parasympathetic, which is primarily controlled by this vagal nerve coming into the SA node, kind of the clock keeper of the heart rate of the heart, and that gets distributed to the rest of the cardiac tissue. So the sympathetic side, while there’s different ways it can be controlled, one of the fastest ways to get your heart rate to 100 is just a lot off the brake, right?

So just rapidly change that amount of vagal tone on the SA node, and I get very fast changes up to a rate of 100. So if you ever want to play around with stuff, you’ll notice that under a rate of 100, it’s relatively easy to kind of change your heart rate. So an example you can do is even have like a Apple Watch or something like that and practice breathing in and breathing out at different rates because your breath will actually change your heart rate.

ever so slightly. And if you’ve got an accurate system, you can play around with very long exhales that increases parasympathetic tone and actually will dramatically drop your heart rate literally within like one or two beats. So very, very fast. Um, the sympathetic system, however, is mainly governed by the adrenal system, by a hormonal system.

So most people are aware of this. If you, for example, if you’ve ever almost had a car accident or something really stressful happened to you, you have it go by, it feels like time kind of slows down. And let’s say it was only like a one second event. If you pay attention, you’ll notice your heart rate will start going super high a couple seconds after that.

It’s not immediate. Because if we want to get heart rate well over 100, what do we have to do? We have to get the adrenals to dump out a bunch of adrenaline, epinephrine, norepinephrine. Those have to travel through the bloodstream. They have to bind to specific cardiac receptors on the cardiac, the heart tissue itself.

Inactivate, you know, for example, beta 1, beta 2, beta 3 agonists on the heart tissue. And this causes an increased contraction and will bump up your heart rate. But that relies on a couple second delay because it’s done by the hormonal system. They have to come through the bloodstream and bind and do all this kind of stuff.

It’s not actually as precise as the vagal system, which is literally. Right next to that essay note. So if you want to get like really down in the weeds and get really hyper specific. If you’re doing an HRV measurement, and most of the measurement systems now do something called a time domain analysis, you don’t need to worry about, but they’re literally just looking at that vagal control of the heart.

And that gives us some idea of HRV and some idea of how much of that sort of parasympathetic do we have. Because remember, we always have some parasympathetic. And some sympathetic, but the H. R. V. Those very, very small changes because this is being done at rest is really looking at primarily that kind of vagal control of the heart.

If you want to get really down in the nitty gritty, the end result is you’re still getting a very accurate marker of the status of that autonomic nervous system.

Mike: That makes sense. And what affects HRV? What types of things are the major factors that that increase or decrease variability in heart rate?

Dr. Michael: Yeah, so lots of things do, which is both cool and maddening for people who train, right? Because when I first started, I was like, Oh, it’s HRV. Is this so cool? I’m going to have a non invasive marker that’s only going to respond to training because training is obviously a stressor. And I started doing it.

I’m like, Oh, wait a minute. Oh, oh, breathing can change it, right? Because our breath, the lung function has to be coupled to cardiac function. What do we have to do? We have to get carbon dioxide out of cells. We got to get oxygen to the cells that includes the cells of the cardiac tissue. So we want some rhythm to be happening between the lungs and the heart.

So like I said, you can play around with different breathing. That’s why if you do meditation or you want to be in a more calm state. Sometimes people will tell you to take a very long exhale. So what that’s doing, that increases that vagal tone and drops your heart rate.

Mike: There’s the, the box breathing method too.

I remember reading about that. It was like marketed as like, Oh, this is the weird trick Navy SEALs use to keep cool under fire. But, um, I mean, I don’t know if it was Mark’s, I actually, but, but that was, it was like, you know, some medium article or something, a clickbait title, but it was just, if I remember correctly, it was four seconds.

Uh, inhale, four seconds, hold four seconds, exhale, something like that.

Dr. Michael: Yeah. So a box of breathing is you’re specifying inhale, hold, exhale, hold. All right. There was a hold at the end. Yeah, yeah, yeah. And you can play around. I would have been a triangle. Mine would have been triangle breathing. Yeah. Triangle breathing.

Hey, that’s your new one. I’m going to market that. Yeah. So lots of stuff affects HRV, which in one way is good, right? Because if nothing acutely affected our HRV. Like, well, why the hell would we measure it each day? Like, what good is it? Not all that useful then, right? Now you get a marker baseline once in a while and you’re good to go, right?

You don’t, you don’t worry about it, but you can’t then use it to navigate training changes day to day or week to week. The downside is that because so many things do change it, examples would be breathing. Hydration will make a massive change to your HRV, which is something people forget about, which is also why alcohol can change HRV, both from alcohol itself, possible dehydration effects, different types of alcohol and sleep, nutrition, mental state, pretty much anything, right?

Because autonomic nervous system is controlling a lot of those different things. HRV is giving us a status of the ANS, automatic nervous system. Therefore, lots of things can change it. So then in practice, how do you make that useful? So my bias is doing an HRV measurement, usually just one time a day, doing it when you have the most stable period before it, right?

So remember I said all these different things can change that measurement. So in the morning, unless you have been doing too much ambient and making bacon and eggs at three in the morning, or there’s like case reports of people painting their house and driving and doing all sorts of crazy shit, you probably have a very stable period, at least one that’s going to be for your physiology.

Probably replicated, you know, one night after the next, assuming length of sleep is about the same conditions are the same. So when you get up in the morning, I tell people just use a bathroom. If you need to sit back down, most people will do the measurement in a seated fashion, which we’ll come back to why that’s important, but the measurement on whatever system you’re using for single point measurements, I still like using the iFleet system.

So instead of iFleet, it’s an i, and stabilize your breathing. So just sit there for a minute or two, just breathe normal, because you want to be in a rested state, and then hit start. On the iFleet app, it will pace your breathing, and it’ll say, okay, breathe in here, and then breathe out there. So remember, we said breathing can change HRV.

So my bias is I like haste breathing when I collect the measurement, because I want that breathing to be the same every time it’s collected, so I can compare one day to the next. And then most systems will give you a score on the top. The hard part is some of those scores usually will be on their own kind of proprietary scale.

In the case of iFleet, they did that just to make it more useful. So they use like a 1 to 100 scale. And on their scale, the higher the number, The more para sympathetic you are, right? So the more fine scale variability you have. So for example, this morning I was 84 the previous day I was 81. So I was more sympathetic yesterday with 81 than I was today at 84.

So a lower score indicates a higher level of sympathetic activation or for lack of simple term stress. Yeah, less variability. I’m sorry, less variability, a lower Score, right? Yeah. Yeah. And that’s, that’s what kind of trips people up a little bit. And on the athlete, they have little indicators that you can move yourself.

It’s a little, I’ll say, Hey, I don’t want to, you know, scale here. How is your energy? How is your mood? How is your muscle soreness? And so it gives you a context that, you know, clients I work with will then rate. So when I collect their data, you know, maybe if we’re doing some very in depth stuff or a tapers getting ready for competition, I may collect that daily.

Most of the time, I’ll just collect it weekly. I can then go back and look, and I have a context now of, you know, sleep and other things that may affect HRV. Because to me, HRV is not super useful without the context of what else is going on.

Mike: Because there are too many things that affect it, right? I mean, it went down, we’re not happy about that, but why?

Dr. Michael: Right, yep, and The first thing I’m going to look at then is what did they report on that context? Oh wow, they reported their sleep was red for the last three nights. Okay, that definitely can be a stressor, so that’s probably what’s going to go on. So I’m going to ask them like, hey, what happened? What time did you go to bed?

You know, I couldn’t sleep because the dog was barking or whatever it was, right? So now that gives me a coaching thing of which I can do some type of intervention. They say it was, Oh, it was nutrition. I decided to do a fast for three and a half days and didn’t tell you, you know, whatever it gives you a way to start a conversation, which to me, I find is super useful because the assumption is that.

Most people would be really good at rating their stress. And what I found is most people are utterly horrible at doing that. You know, yeah, if you’re an elite athlete, you probably have a pretty good idea of what’s going on. You know, a lot of other people, eh, probably not, right? Because I used to have all these arguments with clients, you know.

I’d be like, okay, we’re talking about, you know, eight years ago. Hey, we’re talking about sleep and all this stuff. They’re like, yeah, yeah, yeah, I get it. You know, okay, write down what time you go to bed, what time you get up. And what I found was they’re just like, Oh man, I went to bed at midnight, got up at five again, didn’t matter what I did, nothing changed.

And I’m trying to explain to him that, you know, this is a source of stress, you know, for your life, you’re living on four cups of coffee. Yeah, you train hard, but I was listening

Mike: to a trainer have this exact discussion like a moment. It’s like deja vu moment. Just a few days ago, they were taught. I was just at the bench next to the client and it was the same thing.

Like, okay, so how did it go last night? Oh, terrible. Went to bed. Well, woke up at four, whatever. I don’t know. Like.

Dr. Michael: Yeah. And it’s the weirdest thing because you’re sitting, this one I did in person stuff, I’m sitting in front of the client and they are verbally agreeing that, yeah, I agree. I need more sleep.

Yep. Coach, you’re totally right. Totally right. But they would do nothing about it. It’s almost like it subconsciously didn’t register. So as I started doing HRV, I started having some of those same conversations and then I got really frustrated and I just said, Screw this. So I just put a graph. Here’s your HRV looks like a ski slope headed straight to hell.

Here’s your sleep report. Looks like the same thing. I put them both on the same page and I send it to the client. I go, Hey, what do you think’s going on? And you know, I’m like thinking I know what’s going on, but like, maybe they’re just oblivious and I just did it more out of frustration than anything else.

And they wrote back. They’re like, oh my God. Oh my God. You’re telling me that like when I get like five hours of sleep for three nights in a row, I get really stressed. I’m like, yeah, and they’re like, Oh, I never realized this. And I’m thinking we’ve talked about this for like three months. You know, this is not like, this shouldn’t be a revelation at this point, but there was something about seeing the data that was based on their physiology.

And then their next question was, Oh, what do I do about it? Oh, perfect. I’m so glad you finally asked, you know, so I use it mostly to drive with a lot of clients, just awareness, you know, and try to get them to maintain some ownership over it and also to look at the response.

Mike: Yeah, well, it’s nice that it’s hard data.

It’s something quantitative that you can say, look, see this right here. Here’s what this means. You see what you’re doing there and how it makes that number worse. That is something that is, it’s just more impactful than just talking about abstract downsides to not sleeping enough, for example, especially when it’s something in connection with stress, which can be completely subjective in some ways where you put one person in a situation and ask like, how stressed do you feel?

And they go, Oh, it’s so overwhelming. And then the other person in the same exact situation, same circumstances. And they’re like, yeah, it’s not a big deal.

Dr. Michael: Yeah, because our nervous system operates on a comparative state primarily. So, for example, if you were to come visit me, I do some hands on stuff, some deactivated RPR work.

And my goal of those sessions is to, you know, work on a lot of breathing, do some work on clients. But my goal is to build up the biggest differential. So when they get up off the table and walk around, they’re like, Whoa, this feels like totally different. Right, because if I can get them to feel different, independent of whatever tests I’m using, they realize that there was a difference, and they’re probably bought into, you know, how I show them how to do the exercise and do the activations themselves.

Right, just be like, I live in Minnesota, and if it’s 20 below Fahrenheit in the winter, and you’re outside, and you walk in, and it’s 65 degrees in my townhouse, you’re like, ugh. Man, this feels amazing. It’s so warm in here.

Mike: And that’s, that’s just a little marketing tip out there. If you are wanting to get people interested in whatever you have to sell, if you can deliver quick results, what is a magic bullet that you can actually deliver on?

And you’re not going to magic bullet fix some big thing or deliver all of what you can deliver, of course, but what’s just something you can give them that gets a result very quickly that gets people’s attention.

Dr. Michael: Yeah, because they can feel it, right? So, you know, we can argue later about science and everything, which I love, but.

For most people, because they’re humans, you know, feeling is believing, and that can go astray just as well as it can go right. But if you get them to feel that difference, that registers, because that’s a huge comparison. So if I was sitting in my townhouse all day and it’s 65 degrees, I might be like, huh.

You know, it feels a little bit cold in here, all right, but I walk outside to the mailbox and come in and go, Oh my God, it’s super warm in here. It’s the same temperature, right? I just all of a sudden had that massive amount of comparison. So trying to, to build those things up and using HRV, I like to use it as an educational tool to show them that, hey, here’s how you feel, which is different.

And then in a perfect world, which doesn’t always work, if I can get an intervention, build up a bigger differential on the other side, that would be better now. Sleep is very hard, but in a perfect world, I would say, okay, I want you to go to bed two hours earlier and fall asleep and go from sleeping five hours a night to seven and a half hours a night, right?

That’s a pretty big difference. They do that for four days in a row. They’re definitely going to feel a difference, probably feel a difference the next time they wake up in the morning. So using that to build up, I think, bigger, like you said, differentials is beneficial. But before you can do that, you have to have some level of awareness.

And I think you have to have the client or the athlete bought in and ideally asking you, Oh, hey, coach, what do I do now about this? Because if they’re asking, That means they at least know there’s something that they want to change. You can talk about the trans theoretical model of change and all this kind of stuff, but they are probably much more willing to do a specific action now than they were before.

Mike: Makes sense. How do dietary factors. What type of influences have you seen there? There may not be anything significant. I’m just curious whether it be, let’s say low carb versus higher carb, even certain types of foods. I mean, it wouldn’t be like probably one, Oh, I had a hamburger last night. No, but tending to eat certain types of foods consistently.

What about caffeine? I’m sure plenty of people are wondering about that.

Dr. Michael: Yeah. So we’ll do caffeine first. Caffeine is an interesting one. One of the studies I did was looking at the effect of Monster Energy Drink on HRV, a bunch of different measures, performance, outcomes, well, technically a ride time to exhaustion.

It’s not really performance, but it’s a measure of fatigue that’s been used classically for caffeine research back into the 70s, 80s, 90s. And in that study, we did not really see a big change in HRV, although we did see a change in resting heart rate, you know, ride time to exhaustion was, was pretty mixed.

You can get into the specifics of how much caffeine was used and things of that nature. The caffeine itself is a stimulant, right? It’s working primarily off of adenosine receptors, which in essence is kind of masking your need for sleep. So if you look at cognitive function in caffeine, most of the study, if they are sleep deprived, caffeine will temporarily kind of ameliorate the effects you see up to a point, uh, with a little bit of sleep loss or even sometimes, Frank, sleep deprivation.

In terms of performance, right? Most people you’ve had podcast guests talk about this before, uh, strengthen power, you’re looking at, you know, two megs per kg, up to maybe six megs for kg. So if you’re at say six milligrams per kg, you’re a 220 pound mammals. You’re a hundred kg. That’s 600 milligrams of caffeine at once.

Right. So it’s pretty high. You’re going to be hopped up. Yeah. And you can go too far on that. Right. So you take too much caffeine. It goes from being ergogenic. Helping performance to actually ergolytic detracting from performance.

Mike: That’s interesting. I didn’t know that. And that’s like directly physiologically or just because you feel like shit.

Dr. Michael: Both. Right. And it depends on what skill you’re doing too. Right. So if you ask someone who’s taken way too much caffeine, they just, they feel jittery. They don’t feel good. Sometimes they perform a little bit better. It depends on the individual, but I found if you’re a high level, say power lifter. And you’ve got squat bench and dead and you’re pretty locked in on your form with those athletes.

I’ll actually slowly bump up their caffeine quite a bit more to some pretty high doses. If you’re an Olympic weightlifter, much more cautious, right? Because now you’ve got much more of a skill component involved in there. And we see similar effects with heart rate, right? So if you go to an Olympic weightlifting meet.

Especially at a high level, you don’t see any lifters in the back slapping each other on the head or the back or the ass and like, you know, really getting into it and headbutting each other and whatever. Pretty calm, right? Because as heart rate gets higher, you look at the kind of arousal spectrum, heart rate will increase basically gross motor skills.

So kind of that raw output, but fine motor skills start to go down. Alright, so limbic weightlifting has more of a fine motor skill component than powerlifting. My hypothesis is that caffeine kind of does something similar. If you’re an advanced athlete, you know, more speed and power, probably handle a little bit higher dosage of caffeine.

But for everyone, at some point, if you take in too much, especially acutely, Performance actually starts going down the other way. When we look at heart rate variability, if you get to a high enough dose of caffeine, yep, HRV will actually start to go down, right, because you are driving that sort of sympathetic side through a different mechanism.

However, if you’re at lower doses, the research is really across the board. And the time course of when you pick to measure HRV matters also. So if you take a dose, let’s say, of just old school and high risk caffeine, Pure caffeine in a powder or pill or whatever, and I measure at 30 minutes, you can have a little bit more of a parasympathetic increase.

If I measure again in 60 minutes, I’m now more on the sympathetic side. Peak levels of caffeine are usually looking at 30 to 60 minutes on an empty stomach is when you’ll see peak blood levels. So it’s pretty mixed. There’s some unpublished data that we’ll have coming out this fall where we were dosing people with coffee and trying to standardize for caffeine and looking at just HRV measurements, and these are in, you know, young, healthy college students and kind of the takeaway, although it hasn’t been published yet is.

It may not really affect them that much.

Mike: Up to what amount just out of curiosity. What are your thoughts on that? At least,

is there a point where, so if you guys in the office here, they probably run on average, let’s say between 400 and 600 milligrams per day. And I hear from quite a few people that are in the same range, if not higher.

I’m just curious if In your experience and in your research, there’s a point where you, in most people, it starts to consistently lower that variability at, at certain ranges, or is it just all over the place? Because then there’s also just individual factors in play of how do people’s bodies respond to caffeine?

Dr. Michael: Yeah, so the answer is we have no idea.

Mike: Interesting. Yeah, they’re. Have you seen that in some people, lower amounts have that effect? In other people, it’s higher amounts. So, okay. So, it’s really, it really is kind of a personal thing.

Dr. Michael: Yeah. So, what I’ve seen is there’s a bunch of factors. So, tolerance to caffeine probably matters.

The type of caffeine, is it in coffee? Is it an energy drink? Is it just pure anhydrous? Probably matters. Dosing during the day will matter. Right, because imagine if you’re taking a very high dose in the evening because you left in the evening. Yeah, messing up your sleep. You mess up sleep and depending upon how fast you clear caffeine, which you can look at different genetic testing for that, you may still have smaller levels of caffeine by the time you do another test in the morning.

Probably didn’t sleep at all that night either. And the other part too is that if you’re a healthy person and you’re training hard and you’re taking it, let’s say in the afternoon, My guess, and this is based on very limited unpublished data, it may not matter all that much. Now the big caveat with this is in the real world, I can normally draw an almost linear correlation between amount of caffeine somebody consumes, the amount of stress in their life, and how little sleep they get.

Most people, as caffeine intake goes up, their stress went up, and their sleep usually goes to crap. So now, when I run an HRV measurement.

Mike: Or they’re just not sleeping enough, and they use caffeine as the crutch to get by.

Dr. Michael: Yeah, exactly. So now, when I measure HRV, I do see that they are more stressed. But, was that the caffeine?

Was that the sleep? Was that the outside other stressors they have going on? Is it a combination of everything? Um, probably a combination of everything. And then the last point too is that the form of caffeine will matter quite a bit. So there’s some early studies looking at this at caffeine in the form of coffee versus just anhydrous caffeine.

And you’re like, well, what’s, you know, what’s the difference? Well, Coffee has other polyphenols, different compounds in it that have different beneficial effects. There’s also a very high neurologic association with coffee, right? So if I ask you, when do you typically drink coffee? What would you say? I’m assuming you drink coffee.

Mike: Yeah, I have a couple of shots of espresso in the morning after I work out. I don’t do any before because I like to keep my Caffeine intake relatively low these days. So for me to really notice a difference in my training, I’d have to take quite a bit anyway, and I would, I wouldn’t want to take four or five, 600 milligrams.

So does it really, is it really worth having 150 milligrams before? Nah, so I just do SIM free pre workout and have my caffeine after.

Dr. Michael: Okay, cool. So in your case, because that’s when you typically consume caffeine in the form of coffee, we may actually see more parasympathetic tone compared to a buddy who does two or three shots of espresso before heavy deadlift day.

Right in that state of whether doing it beforehand, they have all sorts of, you know, neurologic associations with it’s part of their pre workout ritual. They’re getting amped up. They’re doing some visualization, whatever, right? So just the smell of the coffee will trigger those associations under what conditions you’ve habitually consumed it.

We don’t really have that with like an in hydrous form of caffeine. So when you look at the research on coffee, Okay. You have to one, look at the caffeine content, right? And then another bugger with that is that the caffeine content of coffee can vary like crazy. There’s an old study from researcher McCuster and he took one of his grad students, he sent them to Starbucks every day during the same time, the same Starbucks, the same, you know, medium, whatever they call it.

I think it was a daybreak coffee. He just brought him back to the lab and they just ran HPLC analysis on caffeine content. What they found was it. You know, varied by like well over 200 percent Wow, holy shit. What? That’s wild. Yeah, I’ll send you the study. Right? So you’re like, well, wait a minute. This is like from a company that is known to have very high standardization, right?

Because you want the same experience, no matter what Starbucks you go to, they’re doing everything they can to keep their process very similar. But yet we see pretty dramatically different levels of caffeine just Transcribed in a coffee type beverage. So when you read the study, you want to look to see did they analyze the specific caffeine content in there, not just standardizing the type of coffee and you have the different neuronal associations with it.

And so Gets to be kind of, kind of messy in terms of the answer of does it have an effect or not? What I tell people in practice is just get a rough idea of how many milligrams of caffeine you consume You’re not gonna be super accurate on it But you can get close and then see if that’s associated with HRV at all Like in my case, I’ve actually started playing around with days I’m doing heavier training of actually increasing my caffeine content and It doesn’t seem to affect my HRV the next day.

The caveat being, if I have it early enough in the day, and I do a fair amount, for whatever reason, higher volume. Like if I just have a lot of caffeine and do a very short session, it appears to affect my HRV a little bit more in the next day. Again, N01, completely anecdotal. So, hypothetically, maybe something about doing work, you’re expending energy, which we know may increase parasympathetic tone, right?

Doing exercise depending on the type of exercise and how you respond can change your autonomic nervous system. So, yeah, so I tell people just to play around with it.

Mike: Tell the body that, okay, we need some time to settle down now, we have to recover from this.

Dr. Michael: Yeah, and at the risk of making it really complicated.

I did an experiment like five years ago when I started playing around with daily HRV and my hypothesis, which was in error at the time was, okay, if I am more parasympathetic the next day on HRV, cool. I’m more recovered, right? But I didn’t pay attention to the deviation of how much higher I went from the norm.

So idiot me, I was, you know, doing the strong man event and I didn’t have any way of training implements. I’m in my garage, so I’m like, okay, I’m just gonna put 225 on the trap bar, and I’m gonna do reps of, you know, 20 to 25 for multiple sets, which, it’s friggin horrible. Sucks. I did that, and the next day I’m like, oh my god, my HRV went up 11 points!

This is crazy! And you know, a couple days go by, do it again, and my HRV went up 9 points again! Wow! So idiot me goes, oh! Maybe this is some new type of recovery work. Anyone who’s listening to this would go, that’s the dumbest thing I’ve ever heard in my life. I mean, it, it feels terrible, but you know, I don’t know.

And I’m like, you know, it feels horrible. So I’m like, huh, well, let me keep doing this.

Mike: I don’t know if I’ve ever even done a 20 or 25 rep set on any type of deadlift. I’ve gone like 12 to 15.

Dr. Michael: Yeah. And that’s no fun. Yeah.

Mike: Yeah. No, I mean, I try, I don’t do it. I haven’t done that in a long time. I don’t, I think I, these days I don’t go over eight or so on deadlifts also.

I mean, it’s a unnecessary in the scheme of things for me and I’m not too concerned about getting hurt, but you start getting, when there is a decent amount of weight in the bar and you start getting up to those types of reps. It doesn’t take much necessarily to tweak something or because if you’re clearly going closer to absolute failure, if you’re doing that.

Anyways, so where did this go?

Dr. Michael: So you can, everybody can picture where it’s going. It’s not good. So I kept doing it like an idiot and I’m like, wow, my HRV still keeps going up the next day. And I’m looking at my training. I’m like, man, all my other training is sucking. I feel like shit. I’m like, what the hell’s going on?

And so then I decided one day to look and go. Well, I wonder what happened to my average HRV because I was only looking at the next day. I’m like, Oh my God, my average is declined by like 12 points over like three weeks. Right? So it’s saying that overall, I’m very sympathetic. And so then I go back and I start looking at the data.

And what you would see is that it would bump up the next day, but 36 to 48 hours later, it would tank even harder. So I’d go up 10, I dropped 15. Right up 9 drop 13 for some reason, and this doesn’t always show up, there’s only one study that’s looked at it. Some things have longer than a 24 hour delay or in that case a biphasic delay, meaning I overshot parasympathetic like I went way up above my baseline.

And then I went very sympathetic on the other side. So the key with that is look at the average.

Mike: Yeah. It’s kind of interesting that kind of an extreme stimulus, which would obviously be a sympathetic event that then produced kind of extreme reaction. in the other direction. And then when it kind of came back to the middle, it was just at a lower place than it was previously.

Dr. Michael: Right. So if you want to get really fancy, and this is pretty hypothetical at this point, now I would tell people that any huge deviation, either up or down, right, even too much parasympathetic or too much sympathetic, that means that your body is trying very hard to recover from that stressor, right now it may be going into the parasympathetic range as really trying to kind of go harder and pull you back and what you’ll notice on the days you train where your parasympathetic is very high most people go oh my god this is a day that i’m going to be like super recovered you know i’m going to test my one rm and it’s going to be amazing And they get to the gym and they’re like, I feel like dog crap.

This feels a horrible, HRV is crap. It doesn’t make any sense. Ah, it’s all worthless, right? Cause if you get too parasympathetic away from your normal, right? Think about what’s going on. You have very high vagal tone. You’re very high autonomic nervous system. That’s pushing you to try to limit performance and try to keep you more parasympathetic.

Mike: Yeah. I mean, as far as workouts go, you’d want to be, you want, you want the opposite.

Dr. Michael: Yeah. Yeah. So if someone has like a, a powerlifting meet and we run their taper using HRV, a lot of times, like the day before the day of the meet, they’re like, Oh my God, my HRV is kind of down. I’m like, perfect. Right. Cause acutely I want you to be more sympathetic on that day.

It’s only one day. We take as many days we want off on the other side. We don’t have to worry about recover. You know, it’s different if they’re in a professional team where they have to, you know, play again and things like that. But for a one off event, I want you to be on the more sympathetic side the day of that event.

Because your performance normally, especially in a speed and power type thing, is going to be a little bit better. Now, I may not want that every single day you go train though, right? Because you may bury yourself into a hole pretty fast. So the context of what’s going on is helpful and being a little bit too parasympathetic or sympathetic isn’t really good or bad.

It’s just something to be aware of and then that can then try to determine what you would do. So if I have an advanced athlete in there, like super sympathetic, I may tell him like, okay, switch days, right? So you’re going to do your aerobic stuff today and you’re going to do your weight training tomorrow.

Because I know aerobic work generally will have a bump in parasympathetic recovery. And if they did their weight training that day, yeah, they could probably do it. Is it going to be horrible long term? Not horrible, but their performance probably isn’t going to be as good. We’ll just flip the days. If they’re very high parasympathetic, I will do something where I want some sympathetic output, but I want to very much limit how much it is.

So I stole this from coach Cal Dietz here at University of Minnesota. Is imagine like if you have a trap bar, you stick it underneath the pins and set the pins on the top. So you’re doing an isometric pull about 2 to 3 inches from lockout. So set that up and then pull as hard as you can against those pins for only about 5 to 7 seconds.

Rest, maybe do it again, like three times. And yeah, that’s probably about it for your training, right? And if you want to do a little bit of grip stuff or whatever, cool. So what am I doing? I’m getting something with temporarily a very high sympathetic output, but there’s no weight on the bar. There’s no eccentrics.

There’s very little muscle damage, very little volume, very little work done. I just want to kind of poke the sympathetic system a little bit more. And see if I can get you back to baseline faster.

Mike: That’s interesting. I think of de loading a proper de load, achieving probably something of that where you are giving it a little bit of extra time, obviously, or extra recovery for the, it’s mostly obviously his joints and tendons and ligaments and stuff, but you also are doing like these days, how I like to do it is I’m using my normal working weights, but I’m just cutting my volume in half and also just shaving a couple of reps off of whatever I was doing in my last training block.

So short, boring. Workouts, but it is just a little bit of a kick that probably to the nervous system a little bit. And then I guess it’s also maybe keeping technique sharp.

Dr. Michael: Yeah, no, I a hundred percent agree with that. Like if someone said, Hey, you know, especially if you’re a little bit more on the performance side, what is the quote unquote perfect taper and like slash your volume by like 60 to 75 percent don’t change anything else.

Yeah. Yeah. Yeah. You know, cause what are you doing? You’re keeping the quality of the work high, right? If you’re a powerlifter, Olympic lifter, crossfitter, whatever, you don’t really want to see and start all of a sudden doing rep work, right? Because that may not be specific to your goal. And you may lose a little bit of motor learning because you’re not doing that practice then either.

But if you’re kind of beat up, your joints are kind of hurting, you don’t want to do a lot of volume that you may not be able to recover from. And leading into that, I’ll do even an overreaching, where like for a week, I actually want to see your HRV start going down. I’ll keep pushing volume until I see that thing start to tank, and then we’ll run your taper after that.

Right, because I have a pretty good idea. Assuming all your other lifestyle is very similar, that for your threshold, we’re probably pretty darn close to it at this point. Caveat with that. You just have to be careful how long you’re gonna run it and you know what level of skill things that you’re doing because your skill can, you know, start to start to drop off because of fatigue and that type of thing.

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That’s essentially 10 percent cash back in rewards points. So again, the URL is legionathletics. com. And if you appreciate my work and want to see more of it, please do consider supporting me so I can keep doing what I love, like producing podcasts like this. On the training side of things, how much does training intensity, and that could be looked at, I don’t just mean load, but let’s just say how hard you’re working.

So it could be volume, could be load, a combination of both. How much influence does that have on HRV? And, you know, just to, To also share, I, I just recorded with mental Henselman’s, I think it was yesterday, the day before we were talking about the idea of, because there’s, there’s an idea out there that you can accumulate central nervous system fatigue from training and that it happens to Regardless of what type of training you do.

And that’s one of the reasons that you deload and he was going into the research showing that that doesn’t seem to be the case. It looks like there is a bit of fatigue and then the body basically just recovers from it quickly with a couple strange cases that aren’t quite understood yet where it was like heavy eccentric bicep.

Curling where there was just heavyweights in untrained individuals where they’re just doing the eccentric on a biceps curl. And that did actually seem to leave some residual fatigue that could be actually quantified. Whereas in trained people. Doing their thing. It’s fair to assume that there is no accumulation of CNS fatigue.

And really the reason for deloading is just the peripheral fatigue. I’m just curious how that jives with what you’re talking about and what you’ve seen in terms of HRV and those things are not equivalent. Obviously, HRV going down does not mean that you have CNS fatigue, but I thought I would just share that as well because it might be relevant.

I was just curious as to your thoughts.

Dr. Michael: Yeah, in terms of seeing this fatigue to be 100 percent honest. I don’t know. I’ve I’ve kind of gone back and forth like I don’t know how many times on that from it’s real. It’s not real. You know now I think it’s probably real to what degree. I don’t know all the I don’t know.

Anecdotal data I have is, you know, measurements using heart rate variability. So that’s kind of the lens that I view it from because, you know, I can get daily readings on that from, you know, all my online clients, which I’ve been doing for almost eight years now, seven years. So that’s. To me, kind of where my framework is from.

Mike: Yeah. I was just curious if there was any sort of overlap there just cause it was an interesting discussion.

Dr. Michael: Yeah. And I think there probably is for sure. What I have noticed is there is a huge amount of intra athlete variability. Like we’ve all seen this, right? Like I had one guy who we worked with him.

We kind of changed some stuff to his training. We did his taper different and he was able to qualify for raw nationals for powerlifting. And. Man, he was training pretty low rep stuff, like five to six days a week. I mean, we kind of rotated exercises a fair amount, but not a ton. And he had a pretty high stress, you know, life, you know, his sleep was a little bit less just because of everything he had going on.

And his HRV was pretty darn good. You know, he only did very minimal aerobic training, his aerobic base appeared to be quite good. I had Another guy who I worked with who was a high ranked natural bodybuilder came to me, was pretty beat up, had some shoulder issues we were working with, and was doing kind of sort of a hypertrophy DUP type split, you know, a little bit more on the powerlifting, accumulate volume kind of area.

And so with both of them, what I did is just a simple experiment is once we had a pretty good HRV baseline is let’s take, you know, one or two days off. And let’s say Monday. So you had Saturday, Sunday off Monday, go to the gym and you’re going to do pretty low rep stuff. You know, really nothing above three reps, maybe four reps.

And we’re going to, you know, do a fair amount of volume on that with, with heavy loads, heavy loads. Most guys I use like trap bar deadlifts and stuff that have a little bit less. Technique, bench press, things of that nature. Stuff that they’re familiar with, that they know how to do, and these are usually pretty experienced people by this point, so they don’t have any problem doing that.

Their technique’s fine, everything like that. And then we’ll take one or two days off, and we’ll just see what is the change in your HRV. And then we’ll come back and we’ll take, you know, similar exercises, or sometimes the very same ones, if I can get enough rest period between them, and just pound a crap ton of volume.

Right, you know, 8, 10 rep range, lots of volume, lots of sets, and we’ll see what happens with your HRV. So, in the guy who qualified for RAW Nationals, like, like we could just beat him up with like low rep stuff and his HRV would like very rarely change. The other guy who was the natural bodybuilder, it took him almost 72 hours to recover from a low rep day.

He was just torched. And he’s like, I don’t feel sore. He’s like, I don’t feel mechanically beat up at all, but he’s like, I don’t want to train and my HRV sucks. However, he could go into the gym and do 30, 000 pounds of volume as HRV would barely move.

Mike: Wow, that’s interesting because generally it said that It’s the high volume that beats you up. It’s not the load as a rule of thumb that applies to more or less everyone. I mean, nothing applies to everyone, but that’s the practical advice that, you know, anyone listening could assume like, Oh yeah, for them, it’s going to be high volume is going to just. Generally stress your body more than high load.

Dr. Michael: If you were to ask me, you know, four or five years ago, I probably would have agreed with that. And now I’m like, I don’t know, man, I think it’s much more individual than what we realize. So for his program, like Monday, Wednesday, Friday, we’d pick a compound exercise. We do, you know, around a five rep range somewhere in there.

So a little bit more on the strength side. And then the rest, everything after that was accessory work. You know, 10 to 15 reps, you know, Tuesday, Thursday was all. You know, kind of classic bodybuilder type, you know, split work, a little bit higher rep range and he did a lot better and he could do, you know, 30, 000 pounds of volume five to six days a week for four to six weeks in a row.

And we’d do a little bit of a taper then for a while. And he was fine. Now, most people, if I did anything close to that amount of volume, I’d just bury them. Yeah. Yeah, that’s a lot. So I think by. Looking at HRV and then changing it can be useful. And then the other part, if we back up and we go, okay, wait a minute, what might be one of the determining factors in quote unquote recovery, right?

So how soon can you go back to the gym and do a similar workout again? And I think it’s aerobic base. Your aerobic fitness level, the people I’ve seen with a higher aerobic base, right? So things like obstacle course racers, CrossFit jumps to mind. I find that they can accommodate a lot more volume, a lot more stress kind of day in and day out and their HRV and recovery appears to be a lot better.

So now with new clients, I run them through a pretty extensive aerobic profile, primarily using the rower to see where their aerobic capacity is. And if it’s really low, I mean, like, Hey man, we might do one or two strength training days a week, you know, how, depending on their psychology of how little I can get away and you’re going to hate life.

But if you can just give me like 68 weeks or longer of, you know, pure old school aerobic training. I can almost guarantee that you’re going to be able to do a lot more work once you come out of that. Otherwise, I think you’re just going to be keep bumping up against this threshold effect where we just can’t get any more high quality work without you making massive changes to your lifestyle.

Mike: That’s interesting. That’s something that it makes sense when I think about it, but I hadn’t come across that connection. Before the, I’m just not looking in the right places, but even just that point of, because I’ve written about just recently, actually in a long articles putting together that how cardio can can obviously get in the way of muscle growth.

There’s an interference effect there, but it also can enhance it. And some of the stuff is like, some points are kind of theoretical, like, okay, we know that. Increased blood flow is good. And so it probably helps, even though there might not be any good research to point to and say, here we go. Here’s these handful of studies are the weight of the evidence, but we’ve all probably even experienced that.

If you do a heavy leg workout and then you do a bit of biking or something later that day, you tend to be less sore. Or if you do it even the next couple of days, you tend to recover a bit. quicker, but this point of your aerobic fitness limiting the amount of volume you can get away with basically is an interesting point and something that I had never really thought of.

Dr. Michael: Yeah. And if we go, okay, what, what’s going on after you get done with a heavy training session, or even from one set to the next. It’s basically aerobic metabolism, right? You’re switching between anaerobic to aerobic, anaerobic to aerobic. You’re going back and forth all the time. And I know from my own training, like when I was getting into just some, you know, body building type stuff, which I don’t do a lot of, I kept track of all my rest periods and how much work I was doing for a couple of years, spend a long time doing a lot more aerobic work.

So what I found was when I went back and did aerobic training. Even the anaerobic, the weightlifting stuff, I was able to slash my rest periods from one set to the next by a lot. Now, it didn’t like happen right away. I think there’s a little bit of a transfer of effect there. So, I think there’s something to that.

Mike: Yeah, I’ve seen research to that effect. I couldn’t tell you. The name of the study or did it, but that seems familiar. I remember writing about that. I remember looking at some research that indicated that’s probably fair to say that if you get more aerobically fit, you are probably going to be able to recover faster in between your sets.

And that can mean that you can also get more done in the time that you have.

Dr. Michael: Right. Yeah. And the main marker there is, uh, these heart rate recovery for kind of the vagal. Reactivation that goes on. Um, and you’re correct that the, I think where people hear this and they go, Oh, so I’m just going to do like mixed mode training all the time.

And I’m going to lift weights and then do a 40 minute moderate session on the treadmill right after. And I’m like, eh, if you’re untrained, that’s fine. But I think as you get trained, and there’s a couple of studies that have looked at this, if you immediately sandwich a aerobic session, especially if it’s right in that, you know, moderate range, 50 to 60 percent of VO2 max, immediately after weight training, We do see there’s definitely an interference effect, right?

Especially for the more speed and power type stuff. We know that bodybuilders aren’t winning marathons, powerlifters aren’t winning marathons and marathon runners aren’t winning bodybuilding and powerlifting events, right? So we know what happens at some point. So I’m a big fan of moving them as far apart from each other as possible.

So like Monday, Wednesday, Friday. Saturday, maybe like weight training Tuesday, Thursday, Sunday, maybe just am old school aerobic training. And if they have time, I’ll move their aerobic training to kind of be fasted in the morning, you know, easy to moderate intensity, only breathe through your nose, that’ll kind of limit it a little bit.

And then their lifting would be later in the afternoon. And I found that that, that tends to work pretty good. I mean, you know, in theory, we shouldn’t see as much of a interference effect there. Interference effect is very widely debated and we just don’t have a ton of good studies on it. But if you look at CrossFit, The level of which you can get kind of a hybrid athlete to get to now is much higher than I would have ever guessed that it was.

So I think we can have more concurrent abilities than what we thought was possible. I think to get there though, having a more polarized type training system is going to be more beneficial would be my bias.

Mike: Yeah. Yeah. And that’s the general advice that I give people. Cause most of the people following me are just wanting to get really fit.

And so they, you know, they have, they have to gain a bit of muscle. They have to gain a bit of strength. They have to whittle away some fat. And for that, yeah, I say ideally split your lifting and your cardio up on, on different days. If that’s not possible, can you put six hours or so between them that that would be good.

And if that’s not possible, can you put it. Can we put some time in between, you know, working to if someone is, but if someone, let’s say they’re cutting and they want to speed up fat loss and the only option they have is to do 20 minutes of cardio or 30 minutes of cardio after a lifting session, let’s say, okay, that’s fine.

And like you said, also, if they’re new to and whatever the body’s hyper responsive, they don’t really have to worry about it. So, yeah, that makes sense. Now with HRV, are there any other? Supplements. So let me just say that. So generally speaking, what we want to see is a high average, right? And it’s going to change though.

And it’s going to go down if especially let’s say with what we’re doing, let’s just take training alone. So if you’re following a program that I mean, really, if you’re following a well designed program, you probably should see some sort of negative impact as you get deeper into a training cycle, I would think, or is that not necessarily the case?

Do you have people who are able to recover so well that it doesn’t really matter so much what they do in the gym and their deloading is more just again straight up for joints and tendons and ligaments.

Dr. Michael: Yeah, I think what I’ve seen is it varies a lot. Someone like myself, like I don’t, I don’t technically ever do any long Tapers, partially because I travel so much that that kind of becomes my own taper.

And if my HRV and everything is going well, I just keep adding longer time periods and I actually will start to add more frequency. So I started recently about four weeks ago, adding what I call just a 10 minute tissue session in the morning. Grip strength is kind of more of my goals, some goals with the rower for performance.

And I’m like, okay, can I get some stimulation of the soft tissue primarily and maybe get a little bit faster remodeling and then I’ll jump on the rower and do some aerobic stuff. Then I’ll do my normal training in the afternoon. So depending on how I feel training in the afternoon, maybe strength stuff, or I may flip it out for more of a cardio session if I’m feeling kind of beat up and then I’ll just kind of intuitively look at my HRV and see how I feel.

And if I need more time off, I’ll just insert a few more days if my hands and stuff feel tendons feel kind of beat up like that kind of soft tissue just doesn’t feel like it’s there. Then I’ll do opposite work. All right. So instead of grip work, I’ll do open hand work, plate presses, open palm work, that type of stuff.

With most clients, they usually like something being a little bit more regulated. So I’ll just push volume for four to seven weeks. I’ll run a taper, as we mentioned, cutting back volume by usually around 50%.

Mike: But do you see in their HRV that it tends to decline as they get closer to the taper?

Dr. Michael: Yes. So in the real world, you have two clients.

You’ve got a client, one whose lifestyle stress is way higher than their training stress, right? So most of your time is going to be working on nutrition. Lifestyle interventions, making sure they show up to the gym, making sure they get high quality sessions, but you may or may not be able to see much of a difference in HRV with training volume because their lifestyle factors are their main stressor.

If you have people that are a little bit higher level athlete, so I got a guy now who does a lot of CrossFit stuff. Uh, his lifestyle is pretty dialed in. He’s, he’s pretty good. He’s doing his, you know, Wim Hof breathing and he’s got a sauna and cold water and all sorts of stuff. So with him. We’ll push volume on him for up to his last cycle was seven weeks, the week right before, since we’ve done this four times.

Now you can have a pretty good idea of what’s going to happen. The overreaching week is HRV was starting to tank. So I’m like, Hey, that’s okay. Time to pull the plug. Let’s, you know, do a taper. Another guy, very similar. He was borderline. I said, Hey, we can, you know, do a little bit more overreaching this week.

I said, your HRV is kind of right on the edge. You know, how do you feel? He’s like, yeah, let’s do it. And he just. Tanked like the middle part of the week. So we kind of pulled the plug early.

Mike: That’s not exactly an answer to your question too. How do you feel? Yeah, let’s do it. Yeah. But how do you feel?

Dr. Michael: Exactly. Yeah. And knowing his personality, I kind of figured that was his answer. But you know, maybe I’m wrong. I’m going to let him run it and see what happens. But I told him like, I’m going to watch your HRV each day. And if it goes South for two days in a row, we’re going to pull the plug. Which if you’re an athlete who really wants to push things.

That’s an incentive for you to be like, yeah, I want to train harder, but oh shit, he’s going to stop me if I go too far. So maybe I’m going to do some more breathing. Maybe I’m going to go to bed earlier. Maybe I’m going to pay attention to more. recovery things because they want to train. So I think you can use it to your advantage too, knowing that you’re going to keep a close eye on it and you’re not going to let them, you know, burn themselves too bad.

Mike: Yeah. Now what about specific numbers? What about specific? I mean, it’s going to be ranges, obviously. So if somebody, if we start looking at it a bit more practically, and one last thing also, I haven’t forgotten for anybody listening, we haven’t talked about nutrition yet. So I’m just curious as to that, but first what is considered, okay, things are good.

Keep going. What is, eh, okay. You know, I think we’re getting to a point where we might have to, or let’s, let’s push a little bit further, but we’re going to have to. to taper, we’re going to have to get a little bit more recovery going here. And then is it, where is it where you’re like, okay, it’s time to settle down for the next few days, do some aerobic work, get some extra sleep, whatever.

Dr. Michael: Yeah. And that’s the hard part because each system will have a little bit different way of how they interpret it based on the app itself. Most of them will use some type of color coding. And so I’ve used the iFleet app and on that one, if it shows red, man, rarely is the red ever really wrong. Right. So if I’m using that app and what is that range?

It’s based on the change. Oh, okay. What we’re looking at. So when I start with some initially, so it’s not like, Oh, one to 50 is red. No, I got it. Interesting. Yeah. And that’s also good and bad because what can happen is if you’ve got a slight decrease, let’s say you’ve got a small decrease. Every day, right to the app.

Some of them now we’ll cross check with a seven day average. So some of them we’ll pick this up, but if they’re only looking at a slight change, it’s like, Oh, you’re green. Hey, you’re green. Hey, you’re green again. Oh, two weeks later. You’re like, my average is like eight points lower than what it was or 10 points lower, right?

You can kind of watch out for that. But most of the time, like on that one, red means that it’s a rest day. Amber or kind of a orange color, like a stoplight system. If I’m just trying to kind of go with the same program, I’ll either flip flop days or I’ll say, man, you look a little beat up. Let’s just cut your volume today by 50 percent instead of doing four sets of everything.

Just do two sets. If it’s green, probably continue on. The other factor that you can use too is resting heart rate. Resting heart rate will affect HRV, lower resting heart rate, you will see a higher HRV overall. Right, because you have more of that vagal tone, you’re more on the parasympathetic side. So I’ve started using now just resting heart rate as a very rough proxy for aerobic base, knowing that if they have a lower resting heart rate, HRV is probably going to be a little bit higher, and they can probably handle a little bit more volume.

So initially, I’m just going to let them run building up volume, and I’m not going to do anything to change HRV for that whole first cycle. So I may get six weeks of data, ideally, without making any changes at all. At the end of those six weeks, we’re going to go back and look to see what were the biggest effectors.

Because I need to know where is your normal baseline, what are things that change it for you, and then I’m going to use that data and kind of play around with it. Because otherwise, if you don’t have a good baseline, you’re just kind of really chasing your tail all the time. And during that time, if the resting heart rate is very high, And by high, I’m not talking like population standard, more athlete standards.

So if they’re like resting heart rate seated in the first thing in the morning is in the 60s, most people would say that’s not bad. But for athletes, I’d be like, to me, that’s on the high side. Ideally, I’d want even a strength and power athlete, like in the 50s, you know, if they’re endurance athlete, definitely in the 40s, you know, some CrossFit athletes I’ve seen in the low 40s, they do pretty good.

Um, if they’re in the high 50s, I can almost guarantee their aerobic base probably needs a little bit of work. So based on that, we may toss in a little bit more aerobic stuff during their first program, their first run through just to kind of get them up to speed a little bit more. But it’s primarily going to be the change of HRV and everybody wants like the, the magic number.

And sadly there isn’t one. If I see a change of more than like eight to 10, even on most of the different app scale, to me, that’s pretty significant. That means something’s probably going on that day. And the little golden rule I have with HRV is that it’s super useful, but at the end of the day, HRV is only telling you.

The status of your autonomic nervous system at that one point in time.

Mike: So it wouldn’t make sense. Oh, if you have a low score that then assume that, Oh, it’s time for a deal. Like maybe not, maybe you just didn’t sleep well, or maybe you had a stressful day at work yesterday or something.

Dr. Michael: Yeah, if I see a seven day average that’s significantly lower, then I’m starting to think, okay, yeah, something’s going on.

And then I’m going to look at, you know, hey, what’s going on in their life? You know, are they stressed? They get in an argument with their spouse or if their lifestyle is all good and we’re pushing, you know, five, six sets of volume on them. I’m like, yeah, it’s probably the training, right? So we’re going to pull back on training even if their lifestyle stress is high.

I may change their training because training is the only thing that they may be able to control in their life.

Mike: Yeah, that makes sense. And another probably useful just I can hear people thinking who are listening. Okay, so I’m not a strength athlete. I’m not an endurance athlete. Again, I’m a person who.

Wants to be fit, wants to be healthy, and I want to get there as quickly as possible. And then I want to maintain it as enjoyably as, and as efficiently as possible. And so I could see a practical use for, and I say, I would probably fall in that group of people as well. A practical use for this could be, for example, is this applies to me.

It applies to most of the people listening. Our training, like you had mentioned earlier, what you were doing with some clients where you have your heavy days, you have your heavy compound days. So you might do a lot of heavy pressing Monday, some heavy pressing Tuesday, some heavy squatting Thursday, and then Wednesday and Friday.

are some additional pressing, but then also some arms stuff. And it’s like for the additional pressing, it’s some shoulder stuff and a little bit more bench pressing. And so what probably could be useful is, okay, let’s say it’s Thursday and I’m supposed to do some heavy squats and it’s going to be a higher volume.

It’s going to be a tough workout. And my HRV sucks might be. A better idea than to, if I can maybe swap depending on what I did the day before, but maybe I could swap my Friday workout for Thursday because it’s just an easier workout or even maybe like you were saying, maybe just do some cardio that day, just something to give the body a little bump and recovery and then squat on Friday and then go on Saturday and do what I would normally do on Friday.

Again, looking at what are you supposed to be doing in the gym today? And does it look like your body is up to it? And if not, if you can make that adjustment over time, I could see that just producing better results. And if you can’t, because you only have these little slivers of time, then I would say me personally, I would just go do the workout and understand that maybe it’s not going to be the best workout.

The weights are probably going to feel heavy, but I’ll get the work done. And then again, like you said, if I’m consistently seeing lower scores, then maybe it’s time to look at when did I last deload? What’s going on? How’s my sleep? How’s my nutrition?

Dr. Michael: Yeah, I agree with that. And I, both clients and for teaching through certs and stuff I do.

You have two options. You have what’s called a eustress or a distress model. So a eustress EU S-T-R-E-S-S is stress you can more easily recover from. Right. So going to the gym and you do a session and a few days later if you had to repeat that session, yeah, you could do it again, right? You’re definitely working, you’re definitely working hard, you’re applying, overload, all that good stuff, but you’re not gonna be not doing anything for a long period of time.

So a distress session would be a session that takes you much longer to recover from. If you have a meet or you’ve got some type of performance event, those usually almost always end up being a distress event. If you’re doing the CrossFit Games, you’re going to get the crap beat out of you for three days.

definitely a distress event. But even for the person who is not highly competitive in that sense, I think that model is still useful, right? Because exactly what you described, you have your two options. The eustress model is maybe I sub in some cardio, maybe I flip days. I’m doing things to try to ensure that my performance stays pretty good and I can kind of continue with my program as close as I can a distress method, which again is a higher risk, which may not be worth the risk for someone who is not a more competitive athlete is I’m going to have.

Three shots of espresso and I’m going to go squat anyway, right? Usually I find with athletes who are not very experienced, who are not competitive, they do way too much distress training and not enough. You stress, you know, every day starts becoming a distress training. And if you watch their progress over time, it’s going down.

But you ask him, you’re like, how hard is your training field? And they’re like, Oh, bro. Bro, I’m training so hard, man. Hashtag no days off. Yeah. Hashtag no days off, you know, more caffeine, whatever, you know, but if you watch their performance, they’re trending down their HRV is on a fast strip to hell. I always think of, I remember talking to Cal Deets once, the university of Minnesota, and he’s writing all this stuff up on this whiteboard for like 45 minutes.

And I’m thinking, man, how am I going to translate this into an article or anything? And. At the end, I asked him, Hey, Cal, all this stuff. So what you’re telling me is I need to do the highest quality work possible as often as possible. And he looks at me and he goes, yes. I think that still applies for people who are not competitive, right?

You want to go in, you want to get, you know, hit your performance metrics because that’s going to drive hypertrophy. It’s going to drive strength. You’re going to burn more calories, just drive body comp. But ideally you want to leave, you know, feeling pretty good. And if you can. go in and kind of do that again, even better.

So you can kind of make a few tweaks here and there, use HRV, use other methods to kind of make sure that you’re doing that over the long term. I think it’s super useful, which is why in formal research studies, HRV prediction of performance is very mixed. You know, the one study they did were HRV guided training versus not guided training, the HRV guided training and not training, they got the same result.

You know, at the end there was no difference in performance and I think they measure hypertrophy too. Did you like the methodology though of the HRV guided? It wasn’t bad, but the HRV guided, I believe finished 17 days earlier or maybe it was 12, but it was a significant amount of time that they finished earlier, right?

So if you look at the study, it could be like, Hey. Using this HRV, we don’t get a better result over the course of a study. That’s actually correct. However, in the real world, if I finished, let’s say 12 days early, man, that’s like, you know, 10 more sessions I could do in order to get better, right? So it’s saving me time that I can spend training more, possibly get a better result, and like I said, acute HRV for strength and power, even a little bit sympathetic, I think is going to enhance performance on that day.

Now again, that’s a distressed model. Would you want to run that every day? I would say no, like I want HRV to be almost flat for as long as possible. Right? Because now I can get in, I can get my work done. Yeah, I may even keep pushing up volume until I see a decline to kind of know where that threshold is.

HRV and acute performance is, is kind of a mixed bag. And a lot of it depends on what factors are you looking at? And by virtue of running a study, you have to control certain factors. And that’s just the nature of running the study and setting it up.

Mike: Yeah, that makes sense. And as far as acute HRV goes, I think of what you were saying with your crazy deadlifting experiment, where if you also saw a notable jump, you might want to take that into account too.

Like, what did you just do? Did you just do a sets of 25 reps of deadlifting yesterday? And then now you’re supposed to go squat heavy today. Might be the same type of process where it’s like, yeah, maybe not. Maybe it’s better to save that. For tomorrow and today do something that is more you stressing to the body.

Dr. Michael: Yeah. And you had mentioned soft tissue stuff too. My current little pet hypothesis is I think in more advanced trainers, I think soft tissue may be the rate limiter to progress, which. There’s not a lot of data on that, but if we just look at simple turnover rates, you know, muscles around 90 days, you know, you look at your right bicep and 90 days, it’s going to, a lot of it’s going to be replaced, right?

And then you look at soft tissue, closer to nine months, right? Depends on what tissue you look at and overloading, all that kind of stuff. If you look at injuries. You know, most people injure soft tissue, like rarely do they injure muscle. It happens, it’s just relatively rare. So there’s some work from Keith Barr and Dr.

Shaw looking at collagen supplementation. They actually used gelatin. They did have a follow up study that used both. 60 minutes before exercise and showing that markers of tissue turnover in soft tissue actually went up. However, collagen or gelatin at other times did not. So for the past about a year and a half now, I’ve been having athletes take 15 grams is what they use in the study.

So 15 grams of gelatin or collagen, about 40 to 60 minutes before exercise and hoping maybe we can get some more turnover into the soft tissue and, you know, maybe see faster results. That’s interesting. I haven’t come across that study. I’d like to look at it. Yeah, I can send it to you. I mean, it’s Is it a randomized controlled trial with a biopsy?

No. Because we’re looking at soft tissue. It’s like if people were like, Ah, this study’s crap.

Mike: Yeah, but it’s also where you’re acknowledging, saying, Hey, look, not sure if this works, but this is extremely cheap and there’s no downside to it. Collagen protein is I know it’s not the same thing, but it’s just, I’ve basically shit on that as I mean, it’s, it’s pretty much trash to your protein.

And a lot of people think though that, oh, if they have the collagen protein, then I think it’s probably mostly women and that it’s going to make their hair and skin and nails prettier and it’s going to be good for their joints. And that’s not true.

Dr. Michael: Yeah, I would say the data on that is. Pretty mixed, although some of the newer data shows that some of those things may be true.

I’d say the jury is still out a little bit for general health. The only studies that show collagen is beneficial for muscle recovery. I don’t trust the studies and they have some interesting sponsorship and the way it was set up and just It doesn’t make sense with all the other data that we have. So for muscle recovery, I 100 percent agree with that on collagen.

Mike: Yeah, I mean, you can just start with the amino acid profile and go, yeah, that’s not as good. I’m sorry.

Dr. Michael: Yeah. It’s missing essential amino acids. Yeah.

Mike: Cool. Well, um, this is a bit random and out of order, but I don’t want to leave it unaddressed and that is nutrition. How does nutrition affect HRV?

Dr. Michael: There’s some interesting studies looking at fruit and vegetable intake will increase HRV, possibly essential fatty acids, EPA, DHA.

Those are more kind of population based than a couple intervention studies. On an individual level, it definitely can affect it, but it’s not as much of a One to one correlation as training and most likely it’s a stressor potentially if you have something that quote unquote may not agree with you per se, but that has other factors, right?

In terms of, you know, sleep and impacting other things. We do know that H. R. V. Is probably related to levels of inflammation. We do know nutrition can modify inflammation, you know, how much those dials can be tweaked and shown up in day to day measurements. I think it’s pretty hard. So what I like to do with clients is.

We have a pretty good idea of HRV baseline. We’ve got a pretty good idea of how they respond to training, their sleep, their other stress factors are pretty good. The first thing I’ll do is I will, uh, bump up essential fatty acids. So normally fish oil. I mean, I’ll even go up to maybe two to four grams for a period of time of combined EPA, DHA.

Mike: Which really isn’t that high for physically active people, especially not for athletes, right? Who want to reap some of the anti inflammatory benefits.

Dr. Michael: No, it’s not that crazy high. I mean, and that’s based off of, I do at home blood testing on athletes. They send it, hit their finger with the bleed on paper, send it in and they’ll run an analysis of EPA, DHA, red blood cell content, all that kind of stuff.

So I find that most people need a higher amount to hit a higher threshold. You can get into cardiovascular risk and other stuff there too. And if everything else is stable after I get that pretty good, which usually I do on a blood test, I’ll play around with micronutrition. And I’m like, Hey, do you want to just, let’s do an experiment where we’re going to bump up your micronutrition a lot higher than what you’ve had.

And most of the time people will see an increase in their HRV over time.

Mike: And what does that look like? Like, are there specific foods that you like to tell them eat more of these things? And here’s why.

Dr. Michael: Yeah, so I mean, I use chronometer to do like a little bit more of a seven day micronutrient analysis on it.

Chronometer is just software that will basically do it for you and it’s not very expensive. I used to use like super fancy dietetics only programs that cost hundreds of dollars. Dollars. And now an online program does basically the same thing for you. So I’ll run that and then I’ll do the, the old school.

Just look at it. I just pulled this up. I’ve never seen this before. Oh yeah. I don’t have anything to disclose about it, but they use. Verified sources for it because other, uh, my fitness pal places, anybody could enter anything. So I was spending more time trying to figure out the thing that they entered.

Was it actually even close to accurate or not than anything else? And it was driving me insane. But yeah, so I like that. I’ll do the back of the envelope where I just look at all their. And then I look for colors like, Oh, wow, you are like not eating anything green at all, you know, or no reds or violets or purples at all.

Right. So maybe eat more berries, mixed berries, things of that nature. Um, and that’ll get you pretty close in terms of polyphenols and stuff like that. You know, the old school, I don’t know if I got this from Chad Waterbury or whoever, you know, kind of eat from the rainbow. You know, if you’re eating a wide variety of colors.

You know, for all the poly phenols and different compounds, we know you’re probably going to be pretty good. Now we don’t know exactly which ones are more beneficial than others. Probably depends on what’s going on. And the other one that I realized up until a couple of years ago, I completely just left out was mushrooms.

So fungi, they’re actually a whole separate. Subclass that have different phytonutrients and things in their beta glucans, all sorts of stuff. So that’s an easy one to look for that people are just generally missing altogether. And just by doing that, I usually find HRV does go up a little bit in most people, not everyone.

I usually find their Ability to handle volume goes up, and I find that a lot of times joint pain will kind of clear up on its own, which is interesting.

Mike: I guess that’s not entirely surprising because of the inflammation interactions.

Dr. Michael: No, inflammation. Yeah, that would be my guess too. I mean, the biggest driver, I would say, of HRV long term is usually aerobic base.

I’ve noticed a huge difference, uh, with that. But nutrition You know, definitely does play a role in terms of supplements. I haven’t found a lot that really moved the needle to be perfectly honest. I mean, I’ve used a whole bunch of different ones just to see and really not that much, you know, things that help sleep and help other lifestyle factors.

I think do help a little bit. I have found that Pretty high doses, like I mentioned, of medicinal mushrooms, especially reishi and turkey tail. If I’m traveling, my HRV won’t necessarily go up, but it doesn’t seem to drop as hard. My guess is that’s probably a immune effect, something along those lines. I mean, I’ve used pretty high doses of CBD.

I don’t really notice a big difference in HRV. I have noticed it’s a little bit more stable, perhaps, but in terms of direct effects, I did this the night before. Do I see a big difference the next day? I don’t really see anything that has a big positive effect.

Mike: Well, that’s not entirely surprising considering the evidence on CBD is all over the place.

And there’s not that much good research that is unbiased. And with Just healthy people that you could extrapolate to you.

Dr. Michael: Yeah, and it’s most of it is in pathologies and a lot of the better CBD research and cannabinoids. Things like that is from Israel and other U. S. Countries because it’s been federal one scheduled one drug for so long in the U.

S. I mean, CBD is not now, obviously, because it’s not psychoactive, but unstrengthened recovery. There’s one super old study. That people kind of wheel out all the time about growth hormone effects and cortisol. And it was a very small study. And I have a copy of the original study and it’s not super impressive.

Sadly, I wish it was, but.

Mike: There’s going to be a lot more research coming. That’s for sure. It’s so hot right now.

Dr. Michael: Oh, there’s a lot more.

Mike: I haven’t gotten behind it just because of the state of the evidence is, I mean, I wrote a long article and recorded a podcast on it that in some cases for some people, of course, it makes sense.

Seizure related things, of course, make sense and it might help with anxiety in some cases in some people, but outside of that. It is not too, not too impressive based on what I have read. And also there’s the problem of you don’t know what you’re getting unless you really know what you’re getting. But, you know, unless you definitely know what you’re getting, you don’t know what you’re getting.

It might have no CBD in it. It might have CBD in it. It might also have THC in it. Which would, if you are an unscrupulous, just cannabis person as the, I love it. It’s like a euphemism instead of calling it weed. It’s now cannabis. Like I partake in pot, but you go, all right. How can I get people to want to buy more of this stuff?

I’ll put a low dose of THC and no one’s going to catch me. And there are no consequences. And then people are going to feel that they’re going to be like, Ooh, I feel good. And so there’s quite a bit of that that is going on as well. So that’s why in general, I just. I personally stay away from it. I recommend people stay away from it.

And then there’s dosing too, right? If you’re going to get anything out of it, you’re going to have to spend with some of these companies, you’d have to spend literally hundreds of dollars a month if you wanted to just get a decent dose.

Dr. Michael: Yeah. I mean, I’ve done a fair amount of work on it starting about three and a half years ago and, and real short.

There is some okay data with anxiety, with provoking people into public speaking. But again, doses were 120 milligrams up to 300 mg, so pretty high. Again, that’s a, you could argue that’s an acute intervention, so you don’t, maybe no need to do that all the time. Quality is a massive issue. There’s even older reported stuff of exactly what you said, high THC amounts that were Well, above the limit right now, I do think though that there is pretty good data for possibly reducing the risk of head trauma and TBI.

So traumatic brain injury, I guess my number one use I would say of CBD and mixed cannabinoids in a hemp oil would be if I have worked with anyone who is in any sports or they may take impacts to the head, mixed martial arts, even soccer, American football, I use a fairly high dose before I go kiteboarding just in case I get dropped out of the sky on my head and from a low dose general neuronal health standpoint, I think you could make a pretty good argument for it.

But maybe there’s a few other case pathologies, maybe sleep regulation, depending on what you have going on. That’s very, very variable. But it’s hard because, as you know, the endocannabinoid system does regulate things like pain, different levels of pleasure, anxiety, all these different, you know, kind of pleurotropic effects across the body.

So there is a potential that it may modify, you know, some of those. So there is some physiologic background that makes sense. But exactly what you said, when you look at the research though, yeah, I would say it’s limited in a lot of areas and is not as much of a panacea as what people claim to be.

However, there are some, you know, I think very useful and legitimate uses for it either. So even though it has all the hallmarks of snake oil, I would be hesitant to kind of toss it entirely out. So, which that’s not a simple story. Nobody wants to hear it.

Mike: Yeah. Yeah. You know, that makes sense. And I didn’t come across that anything on trauma and treating head trauma, but that’s interesting.

Dr. Michael: Yeah. I’ll send you a whole paper I need to release at some point. I’ve spent fricking two years on undoing it and remind me, I’ll send it over to you. But the short version is in rat studies that got whacked on the head, having CBD mixed cannabinoids, uh, help prevent the blood brain barrier from opening up.

So if you take a big walk to the head, like two big things happen. You have glucose metabolism basically goes offline, so you have a massive energy shortage and potentially you can have your blood brain barrier start to open up because of the damage. And when that starts to open up, you’ve got all these things that flood into the brain, causing neuro inflammation, which just exacerbates everything else.

So CBD and mixed cannabinoids and even THC to some degree. May help with both of those so they can reduce some of the the neural inflammation going on Which may help some of the energy metabolism stuff Exogenous ketones ketogenic diets could help with that George Brooks’s lab has done Lactate infusions looking TBI blood brain barrier integrity again This was done prophylactically before the little mice got whacked on the head That may be beneficial for that, and even in a study looking at a car accident, so people who had a TBI from a car accident, obviously, if that happens, most states, you have to run a toxicology screen.

They went back and retroactively looked for people who had positive THC on their talk screen versus mortality outcomes and was several hundred people with a TBI. If you had a positive talk screen for THC, your risk of or how much, how sooner you died, right? Your mortality risk actually was better. So some super interesting data in that area.

A lot of stuff we don’t. I don’t understand yet, but I think it might be useful for that. And hopefully we’ll have more data in the future. Again, we’re never going to have perfect randomized controlled trials because no IRB is going to prove, okay, you people get CBD, you people don’t. We’re going to whack you all in the head and give you a TBI and see what happens. So.

Mike: Maybe when we have clones, even then it probably won’t be allowed. China, they have these half human hybrids. Maybe we can use like a half cow, half human.

Dr. Michael: Yeah, there’s, yeah, there’s all sorts of crazy research in other countries, so yeah, who knows?

Mike: Well, um, so last question for HRV is, so for somebody who wants to start tracking their HRV, I know you’ve mentioned a couple things in terms of apps and devices and so forth, but maybe just quickly let them know, all right, so get one of these things to track your heart rate and then get this app, hook it up and off you go.

Dr. Michael: Yeah, I like right now, I mean, there’s, Did you have a fair amount of systems on the market that are pretty good? Most of the time you’re going to need a dedicated system to do it. Yes. It’s probably gonna cost you a little bit of money. When I was presenting, I was teaching a class at St. Thomas when I was an adjunct there.

And this is like when HRV just started, I had my old Android, like Razor one phone and I put it up and I displayed my HRV on the screen and all the students are like, Oh my God. Your phone, it’s so old. I’m like, it’s two years old at this point. And I’m telling all about it. Hey, you can get HRV on your phone.

Now this stuff used to cost you like 10, 12 grand in the lab. And the app’s only 8 when they’re like what 8 for an app. That’s crazy. I’m like. No, that’s like cheap. This is going to be like thousands of dollars. Um, so, but it will cost you some money again, not that much. It’s usually a one time thing. You can use the Bluetooth heart rate strap is what I primarily use.

There are some dedicated finger sensors that will work also. Is there any brand that you like, like any specific product? So my bias, what I use for all my online clients is either the Aura Ring or the iFleet. So I like the iFleet a little bit better if the client will be able to take a single point measurement in the morning.

Can you spell that? Yep. Aye. T H L E T E.

Mike: The letter I.

Dr. Michael: The letter I, yep.

Mike (2): That was a bad branding choice. Bad name choice.

Dr. Michael: Yeah. Yeah. But they have papers showing that it has been verified. It’s the same one I’ve used for quite a while. It does have all the context in there. The interface is pretty nice. So if the athlete will do a single point measurement in the morning, that’s what I’ll go to because laying down, especially as you start getting into low heart rates, you can have something called a parasympathetic saturation.

But in English just means that you have such a high vagal tone because you’re laying down and you’re a trained athlete that all these other stressors just don’t show up in your measurement, right? But if you are seated or your stand now, the heart has to work a little bit harder because it’s got to work against gravity, but because you’re in that same position every day.

That doesn’t really factor into a variability analysis. So most people will do seated. If your heart rate starts getting down in the morning in the low 40s, you may have to do it standing. And when you do that, you have a little bit of that sympathetic tone that gets you out of that super high parasympathetic saturation.

And now other stressors will show up in the measurement. So if someone says, Hey, I’ve been doing this stupid HRV thing and my HRV never changes. My first question is, What’s your resting heart rate? And how did you measure it? If you’re like, Oh bro, my resting heart rate’s 43. And I measure it laying down.

Yeah, I would not expect to see a big change. So do it seated first thing in the morning. I do like the aura ring or as a ring that goes on the finger, we’ll measure sleep with about a 70 percent accuracy. According to the studies, they published the HRV on aura is super accurate. The reason they do it on the ring is because they can get access to the vessel there.

They can map out the entire waveform. They can tell you temperature. They can tell you respirations. Even they can pull that out of the waveform. It’s very accurate. The downside is two things. One, it’s collected over the whole night’s sleep. Which is good to see what your kind of average HRV is. But if your sleep is changing a little bit, now your collection period is a little bit different because it’s collected over that time period.

So that can, it’s just a changing variable. Some people, if their resting heart rate is super low, their HRV may not detect enough change to accurately reflect training and other acute stressors. But if you want something that’s just kind of a And overall HRV to see where you’re at. It’s definitely useful.

My bias still is if you want to get pretty specific and start dialing in changes to your training and you’re, you know, a little bit more of a trained mammal, I still like doing the single point measurement in the morning. Plus a lot of the training interventions and the studies we have so far, which there’s not a ton, but almost all of those use that single point measurement as a proxy for it.

And it’s also closer to when you’re starting your day and that type of thing too. So it’s, it seems to be a little bit more reflective. But those would be the main two that I personally use. You know, there’s other systems from, you know, mega wave elite HRV, HRV for training, and there’s, there’s a whole bunch of them now that can be useful too.

Mike: Yeah, that makes sense. Great. Well, um, I think we should wrap up. This was, this was great. This was a fast two hours. At least it felt it was a super.

Dr. Michael: Yeah, it went by pretty quick!

Mike: Yea, it was very informative. That was awesome. So where can people find you find your work? Are you, I’m assuming that you probably have a wait list as far as clients and such good, but how does that world work for you.

Dr. Michael: Yeah, so the best place is probably just on the website, which is just Mike T and nelson dot com. I do have some spots open for training once in a while. There’s usually a little application there. Usually if I announce any open spots for training, it’s through the newsletter first, so anyone who’s on the newsletter gets kind of first crack at that.

If you go to the top of the website there, you can get a free offer and get on the newsletter. Newsletter’s free, send out content usually about five times a week and I spend a lot of time writing for that. So most of my content right now goes through the newsletter. So there’ll be a way to hop on there at the website which is just MikeTNelson.

com and it’s probably the best way I’m on social media and Instagram once in a while. Wild, but probably not all that much some days. Because you’re too busy doing real work. Yeah, I have a love hate relationship with all of it, to be perfectly honest. No, I’m the same way. Between you and me, I probably never even post anything on there.

Mike: I’ve said that a number of times. I only use it for work, actually. I don’t really have a personal social media account. I just have my externally facing work related stuff because I don’t like social media.

Dr. Michael: My social media is just all mixed, you know, up until probably three months ago, my Instagram was all just pictures of dark coffee and death metal concerts and weights.

So the newsletter is more geared towards people who, you know, want information that’s that’s digestible. And I find I just like writing for people who want to hear something instead of trying to appease to whoever happens to like my stuff on Facebook, which I could care a lot less about it.

Mike: Yeah, no, I understand.

I mean, what I do is I will repurpose educational stuff that I create, so I’ll repurpose stuff that I’ve written, turn it, turn it, you know, turn it into whatever you, whatever the limit you get on captions, 2100 characters or something.

Dr. Michael: Yeah. I just started doing that too.

Mike: Which is a nice way to get more juice out of the work that you’re doing.

And yeah, you’re not going to get as much growth or as much engagement or likes from stuff like that, as opposed to, well, if you were a woman, it would just be your butt and your boobs. I guess for guys, it’s either either has to be abs or it needs to be large amounts of weight and ridiculous antics, but you’ll attract the right people though that each follower that you do get is obviously going to be somebody who appreciates the education and appreciates the information. And so that’s how I look at it, at least.

Dr. Michael: Yeah, no, I agree. And, you know, part of the newsletter is also, it’s like, yeah, you have to go find the website and go to the top and actually send me a legit email address to get on.

And that’s done on purpose because, you know, I don’t, I only want people who are, you know, interested in it because I want to give them good information. I want them to actually take action on it so they actually get better. You know, I’m not trying to impress everyone else who’s not going to do anything with the information that’s, you know, I purposely require you to make a little bit of action on your end to kind of weed out people who are a little more serious over those who are not.

Mike: I’m with you. We do the same thing. Well, Mike, this was a great discussion. Thanks again. And, uh, I look forward to doing another one. You are a wealth of knowledge. I like it.

Dr. Michael: Yeah. Thank you very much for having me come on here and ramble about all sorts of stuff and especially HRV. So I would, uh, Encourage people to do some HRV, play around with it.

It’s a useful metric to see how your body responds. Perfect.

Mike: Hey, Mike here. And if you like what I’m doing here on the podcast and elsewhere, and if you want to help me help more people get into the best shape of their lives, please do consider supporting my sports nutrition company, Legion Athletics, which produces 100 percent natural evidence based health and fitness supplements, including protein powders.

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