The Best Way To Know How Stress, Supplements, Sleep, Sex & More Affects Your Nervous System: The Latest News About Heart Rate Variability (HRV) Training

In this episode of the Ben Greenfield.

Fitness show, you can download your Fitbit data, your Withings weight data, your Webings blood pressure, your MapMyFitness data, your calories in, your calories out, and then look and see, is there a correlation between my HRV or my stress levels or even my blood pressure and all these other biometrics that we're gathering using other vendors devices. That's why it's good to see your cardiologist and just get a good baseline so you know where you start. Because PVCs are normal too. I mean, healthy people have PVCs. The question is, how many do you have?

He's an expert in human performance and nutrition, voted America's top personal trainer and one of the globe's most influential people in health and fitness. His show provides you with everything you need to optimize physical and mental performance. He is Ben Greenfield.

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Hey folks, it's Ben. Ben Greenfield here. And measuring your heart rate variability, also known as hrv, is, in my opinion, one of the most valuable ways to begin your day when it comes to self quantification. A simple three to five minute period of self quantification that tells you exactly how stressed your nervous system is and how prepared your body is to train and how everything from stress to supplements to sleep to sex to a whole bunch more actually affect affects your body and your brain and your nervous system. And I've certainly produced tons of content on exactly how HRV works and how to measure it. This podcast that you're about to hear, therefore, is not an HRV101 podcast. However, if you go over to BenGreenfieldFitness.com HRV2 that's BenGreenfieldFitness.comHRV the number two. I'm going to put a link to all of the other podcasts and articles because there's a whole bunch of them that I've done on hrv. So if you want to go back and take the deep dive on everything from the different tools out there, to the myths and truths behind hrv, to how I found out about it in the first place, to what I use it for, to how to hack your vagus nerve, to a whole bunch more, you can go over to BenGreenfieldFitness.com HRV2 and do it There. But anyways, in this podcast episode, what I want to give you is the latest news in the world of HRV and HRV measuring technology, how to measure HRV without necessarily having to put on the big bulky chest strap and some of the cool new things that I and my in house HRV expert on today's show have been doing when it comes to utilizing HRV data to get better results for ourselves and better results for our, our clients. So who is my guest today? It is Jo Beth Dow. She, I should say, is Jo Beth Dow. Joe Beth is the co founder of Sweetwater Health who I worked with to design what's called the Nature Beat Heart rate variability tool, which is the exact app that I personally use to measure my own morning heart rate variability. She has spent her entire career in high tech designing and producing a whole bunch of different state of the art networking technologies, high tech companies and apps, including this Sweetwater Health company that really specializes in hrv. They're a mobile health software technology company that have, they've developed this patented algorithm for actually continuously monitoring your stress levels and your nervous system. And so she's one smart cookie when it comes to hrv. We're lucky to have her on the show today and as a resource. So, Joe Beth, thanks for coming on the show.

Well, thank you, Ben. It's good to be here. I appreciate it.

Yeah. And you know, one of the first things that I wanted to mention to you was I actually measured my HRV this morning as I do every day and just just to kind of give people a little bit of a glimpse into how I use this data. It was low and frankly I kind of knew it was going to be low. I had a rough weekend of training. I had a very hard workout yesterday where I was, you know, I'm kind of starting to prepare for this Spartan World Championships event. So I'm doing a lot of carrying and a lot of climbing. And so I have this incline treadmill out in the garage and I was doing 400 meters on the incline treadmill, then carrying a couple of sandbags up and down the driveway and then 400 more meters, then carrying a keg, like a half empty keg up and down the driveway. Then 400 more meters and doing farmer's walks with kettlebells around the house. Then 400 meters and 20 pull ups and just doing rounds and rounds for that and just of collapse at the end of that workout. And was not surprised when I logged in this morning to my heart rate variability app and it said my HRV was something like 79. Right. Usually it's in, like, the early to mid-90s. So this morning I got up and I did a little bit of yoga in the sauna, a little bit of cold pool, a little bit of foam roller, and kind of like a deep restoring, relaxing morning. And that's exactly the kind of actionable data that. That I get from hrv. So I thought I'd share that with you. I'm being a good boy and actually using my data.

You know, Ben, the first time I ever saw your HRV numbers and I analyzed them several years ago, I literally yelled out, nobody was in the room. And I saw your numbers, and I just went, oh, my God. I had never seen numbers like that because at that time, very early in the beginning, we were starting to get athletes, but we really didn't have any elite athletes. So you were the first elite athlete that I saw. And when I looked at your numbers, your power levels were so incredible. It was like nothing I had seen. You know, we mere mortals have power levels in the, you know, 800, 900, and there you were at 13,000. And I thought at first maybe this was a mistake. Then I realized it wasn't, and it was just your basic conditioning.

Well, part of it, I think, is condition. When you say power, I know you're referring to the strength of the sympathetic.

Nervous system and parasympathetic.

And strength of the parasympathetic nervous system that the HRV app measures. I'm convinced, though, because I work with so many athletes myself, and I look over their HRV numbers, that it's really not necessarily a sole matter of physical conditioning, but it's a matter of prioritizing having other variables present in your life that improve the health of your nervous system. Meaning I place a great deal of emphasis myself on things like relationships, love, gratitude, rest, relaxation, detoxification, healthy eating, grounding, earthing, good air, good light, good water. Not a lot of Wi fi and Bluetooth exposure. And I think a lot of those things add up because, frankly, I work with a lot of people who I would consider to be far more fit than myself, who do have. And I'm not trying to brag, but they do have lower HRV scores. And I think a big part of it is because they place too much emphasis on the buffeting of the body and not enough emphasis on caring for the body is like a human battery, in a sense, when it comes to things like grounding and earthing and electricity, but then also love, relationships, gratitude, things like that.

I fully Agree. I fully agree. And I've been on so many panels where people talk about how to increase your hrv. You know, what's bad for your hrv. And no one ever mentions the love factor, the emotional part of it. Every time I would Skype with my daughter when she was away at college and of course I'm measuring myself all day because I'm working on this, I would see my HRV increase and my stress levels decrease. Love, touching, you know, physically touching. So take your partner and hold hands. The more you physically touch, the higher your HRV is going to be.

Yep, yep, absolutely.

Oxytocin, the emotional part between sleep and happiness and love. That's what increases your hrv. I've been measuring my HRV for so long. In the morning I know what my HRV is going to be before I measure it. Just by the way I feel emotionally and physically.

Yeah, I don't know if I told you this. I actually, for a short period of time, just to see what the body would actually feel like, I did injections with oxytocin before sex and before bed. And one thing that I didn't know it was, my heart rate variability went up very high. Which is what I like is you can use this as almost like a self quantification tool. Anyways though, the first thing I wanted to ask you is this idea behind the actual HRV algorithm because there are, there are a rising amount of data, a dizzying array of HRV tools that are out there. You know, we've got Elite HRV and my Fleet and Bioforce, you know, and all these different companies that I know do a really good job at developing tools that will measure one's heart rate variability and the strength of one's nervous system. But I'm curious about the actual algorithm. Can you explain? Because I know that what your company does is you specialize in measuring your stress levels via an algorithm. What is the algorithm that you're using? You know, when I'm opening and I'm literally holding my phone right now, I've got my Nature Beat app open. What is the algorithm that's used in here? Is it any different than any other app that's out there?

Well, you know, I can't speak for the other apps because their algorithms will be their intellectual property. So I'm not privy to see exactly how they're implementing their algorithms. But what I can say is Nature Beat is clinical grade hrv and that's what we're really fanatical about. So when we started to build this product, we wanted to make sure we had the absolute most precise clinical grade HRV out there. And I believe that we've done that. In 1996, the HRV standards were set by the task force of European Society of Cardiology and the North American Society of Pacing Electrophysiology. Quite a mouthful. But they define the standards and they define the algorithms. And where there's a little confusion is people will see their HRV score, right? And they'll say, and then I used this other product and they had a different number for the HRV score.

I get that a lot. People will be like, oh, I was 100 on this one, and I was 120 on this one, and I was 60 on this one. What do I do?

That's right. So there's about 32 different HRV metrics and they're all HRV. And you can define metrics in the time domain. You use algorithms for the time domain. In the frequency, there's even nonlinear algorithms that you can use. So what every product does is they will take one of those HRV numbers. There's about 32 of them. And what we do is we use the RMSSD and then we put it through a log algorithm, so a log formula to get a nice number between 1 and 100 that the user can understand. So every vendor out there is going to have their own special number. And that's why those numbers are so different. And I don't really know what root number they're using. They might be using rmssd, they might be using sdnn, I do not know. But everyone's going to have their own special HRV score. One of the things we do is on our geek screen you can see a lot of the HRV numbers, rmssd, lf, hf, the ratio in real time. And so our numbers are all exposed.

Right? Just a quick thing we should throw in there is that rmssd. For those of you who are into statistics, you probably know this, but it's the root mean square of the successive differences. That's what that refers to. It's used to assess heart rate variability. And that number, basically, in plain speak, you're smoothing that number over to turn it into a readable value that's between 1 and 100. So that someone can simply have that logical value of 1 to 100 versus having that RMSSD number, which is, you.

Know, frankly, 34.5 or something like that. People wouldn't understand that. What's interesting is in the beginning, when all the athletes started embracing our product, we actually had to change the algorithm because their hrp, their RMSSD was so high they were blowing way past 100. And so we actually increase the log to try to keep everybody below 100. So yes, that is our special number. Scnn is another value in the time domain and that's another statistical measurement. And so there's lots of them and you can see most of them on the geek screen.

Got it. The geek screen being after I take my HRV measurement on the Nature Beat app, the screen that I can then open to get more detailed, a more detailed look into. Well, let me put it this way, you know, for a lot of people know that I wear for example this, this self quantification ring called the Aura, which I love because it will take my HRV all night long while I am asleep. But at the same time I still get up in the morning and I do my nature beat measurement because that tells me on this geek screen things like, well, it's low, it's high, but what's going on? Is it my sympathetic nervous system? Is it my parasympathetic nervous system? Do I need to give my aerobic system a break this day? Do I need to? Or can I handle a hard anaerobic energy system workout? So I like that geek screen. I actually use that pretty comprehensively every single morning once I take my actual measurement.

And while you're taking your measurement during the session, if you look at the monitor page, there's a little gray button and it'll say stats right where the animated ECG is. If you toggle that, touch that button, you will get your, the geek screen in real time. So you'll be able to see your LF and your hf, changing your rmssd, your heart rate, signal quality.

Right? Exactly. Yeah.

And you know, touch it again, tap that little gray button again and you'll see the instantaneous RR screen.

That's the graph. That's the graph screen.

That's the graph. Yeah. And that's important, especially if you're using the zoom. And I know we're going to get into that, but you want to check that screen because if ever you see red lines, normally it's going to be white. That instantaneous heart rate. If you see that line go red, that means that there was bad signal quality and that I've thrown that RR out. So we got some sort of electrical artifact. And in fact that's also part of our clinical grade hrv. I use some very complex filtering algorithms which is very important. So I need to filter out electrical artifacts. So if you get bad signal. I can't have that in the array of rrs. And so those filtering algorithms are really critical. And I noticed with some of the other products, the other vendors products, some of them weren't even using a filtering algorithm. Some of them use interpolation, which is where you throw the signal out. That's a bad rr. But then they sort of guesstimate where your heart rate would be. And that's bad too because that's going to give you a false high reading. And so our filtering is critical and I work on that all the time. And then what I'll do is I will take our results and continually compare it against Kubios. Now Kubios is the gold standard. It's a, you know, a PC or Mac based app product, Cubios like Kub.

Ios.

And it was developed by the University of Finland, it was a free product. I think they may be charging a little bit now, but it is the gold standard for HRV measurements, but it's not in real time. So what I do is I'll upload the RRS and I will look at the Kubios results and I will compare them to the nature beat results and make sure they're identical both in the time domain, frequency domain and nonlinear.

Okay, got it.

So that's, I'm continually checking to make sure that we are still accurate. And Kubios is a wonderful advanced tool. I use it when I analyze our clients and it's really great. It's sophisticated, but it's a good tool if you really want to get down into your numbers and look at things.

Yeah, I downloaded it before. I think you sent me the link and it was too much for me. I just wanted to stick to the plain, easy stuff I could access within the app. Which is actually what I wanted to ask you. But although I'll tell you guys what, for those of you listening in a link to the Kubia stuff in the show notes over@BenGreenfieldFitness.comHRV2 if you want to take a deep dive into it.

Ben, if you share your session with yourself, I send you your raw data and you can look at that. I send you your hrv.

You mean my Cubios data, then I'll.

Send you along with that is a cubiosready Txt file and that's the file you can use to upload into cubios. So I have to massage the data, I take the labels off and it's expecting a certain text format and that's what I do. So the user, he's got a Cubios ready file. He can go up in there and he can look.

Got it. Okay, cool. I want to dive into a few of the options on Nature Beat.

Okay.

So when I open it up, I roll over, I put on my right now I use this Bluetooth chest rate strap. But I want to talk to you about this other thing that you can do now without using the chest rate strap or the chest strap. But first I want to just delve into the screen. So when I press start, I've got four options here. I've got my phone open right now while I'm talking to you to go over these options. I can monitor stress, I can monitor heart rate recovery, I can monitor HRV for training, or I can do what's called a three minute HRV checkup. Can you walk me through the difference between each of these?

Sure. So they're all the same HRV sessions. So the same algorithms apply, the same code is running, but the session types are different. The monitor stress session is of variable duration. So you start your session and then you can end it anytime you want. So if you want to measure your hrv, when you go into a business meeting, you just start or stop or when you're driving or if you're meditating, it allows you the flexibility of creating a session, whatever duration that you want, and the heart rate recovery.

So I could, for example, push monitor stress and then I could go into the weight room and I could do a whole weight training session and it would be monitoring my HRV during that entire weight training session.

That's correct. That's correct. So the heart rate recovery is going to be an HRV session again. But most importantly, when you stop the session, there's a one minute countdown timer. And what we want you to do is when you do stop exercising, you hit the stop button, the timer stops and you just sit or stand, don't move around. And it is going to measure the difference between your heart rate when it started and how long it took your heart rate to recover after one minute. And of course that's a sign of health and robustness. Also, how quickly can your heart rate recover?

So all that, I mean, that seems pretty straightforward. I could do that with if I wanted to, just my finger on my carotid artery or whatever. So that's not looking at heart rate variability recovery, it's looking at heart rate recovery.

Nope. It's looking strictly at heart rate. And for people who are interested in seeing what happens to their HRV when they exercise of course your HRV is going to go down to zero when you exercise. So it's really not a good test, but some people are very interested.

Well, it is actually. And I'll tell you why I think it's a good test. Because, for example, I've tried out different exercises in the weight room and I've found that the ones that drop your heart rate variability the most, meaning the ones that stress your body the most, actually seem to be the most beneficial. With the one that seems to drop my HRV the most when I test HRV while I'm weightlifting, is the backstory. Squat. Putting a heavy weight on your back and doing a squat plummets heart rate variability compared to just about any other exercise. And I think it's because it's extremely stressful to the body. Right, Like a giant lion has freaking jumped on your back. And so. But at the same time, you recover and you compensate or you recover and you recuperate from that and you get a compensatory fitness response. So it actually can be used to get some pretty good data and find out, hey, concentration curls don't do jack squat for me, but back squats do.

Boy, that is really a good point. And I actually never thought about that. But that does make a lot of sense. Yeah, that makes a lot of sense. So that's heart rate recovery. So if you're interested in exercising and seeing your HRV while also getting your recovery score, you can do that. And then the HRV for training is a three minute session. It can also be a five minute session that's configurable. If you look at your monitor screen and you touch the little gear on the top right hand corner, you can change the duration from 3 minute to 5 minute. For your HRV for training, if you can sit for 5 minutes or lay down for 5 minutes, 5 minutes is even better. The more data we get, the more precise it's going to be. But three minutes is pretty darn good, especially for the time domain. But things have a tendency in the frequency domain. Your LF and HF really settle down at about 5 minutes. It is a 5 minute moving weight window that's used for the algorithm.

Okay, got it. And do you think there's a huge difference between measuring for 3 versus 5? Because I used to measure for 5 when I'd wake up in the morning. And just because the app has changed and we have a new version out for Nature Beat, now it's three minutes. Have you found there to be a big difference?

No, no, I Use three minutes.

Okay.

There's a little bit of a difference, but it's not enough for me to sit for five minutes.

Okay.

So I think three minutes is definitely good enough. One minute is way too short. And I see some of the other products, they do it for a minute. We found that people could only really sit for three minutes.

Okay.

Or lay down into it for three minutes. And the most important thing about the HRV for training, it is a three minute session. We want you to do it first thing in the morning, preferably when you're in bed before you get up. I don't do out of bed. I have coffee, I go to my desk, I sit down and I make my session. You know, I create my session at that point. But the most important thing is you want to be comparing apples to apples. So you want to be doing it at the same time of day in the same position. So if you're sitting up or if you're laying down, just be consistent because we're going to be comparing that from day to day. And you want to do it before all hell breaks loose in your day. Right. You want to do it while you're still well rested. Because we want to see how well you have recovered from sleep. Because sleep is everything, right? So this is when your nervous system is going to recover. This is when your body is going to recover. And so that's why we like that first morning measurement. And then what we do is we will graph it and we will keep track of where your HRV is. Every day we create a trend line, which is that yellow line. And if you fall below your trend line the first day, we'll recommend an easy day. If it falls two days in a row, then we do recommend a rest day until it comes back up.

Right.

So that's the HRV for training. And the special part of HRV for training is we keep track and create a trend line.

Okay. The other thing I noticed that is on here is the breath pacer. Does that breath pacer automatically come up when it detects that I'm stressed? Or is that something that I'm supposed to select and do myself when I feel like I need a breath pacer?

Both. So you can just use the breath pacer whenever you want to. If you're waiting for your dental appointment, you want to relax, you can use the breath pacer or you can set up the breath pacer so that it does trigger on a stress threshold. So you might want it to trigger on high or you might want it to trigger at Certain points. And then what will happen is when we detect that you're at that stress threshold, it'll pop over to the breath pacer and you'll see the breath pacer and the picture. And the breath pacer is a 4 second inhale, 6 second exhale. But you can use other breath pacers. You know, there are other breath pacers on the market now. There's all different combinations.

You said this one on the Nature Beat app. And by the way, for those of you listening in, you can probably hear that electricity in the background. It's because I'm actually, I rarely do this, but I'm actually using my phone while Jo Beth and I are talking to open the Nature Beat apps. I suppose I, I could probably put this in airplane mode and it would still work, wouldn't it?

Yep.

Okay, so back into airplane mode. Here we go. So the breath pacer. The breath pacer, by the way, you said that's a four count inhale, six count exhale. That, that's set for. Okay, got it. All right.

But if you prefer a different one, if there's lots of breath pacers on the market, if you just want to meditate with a breath pacer, there's a lot of free ones out there with all the different breathing techniques.

Okay, got it. The next thing that I wanted to ask you about the app is after my reading or during my reading, if I press my stats button, I can go in and I can look at the LF and the HF score. The LF is a measurement of the strength or resilience of my sympathetic nervous system. And the hf, the parasympathetic. Correct.

Yes.

Okay. Is there any other things that I should know about LF and HF in terms of ratios, in terms of any other data or any other information that I should be getting from those two values?

Well, you know, the LF and HF come from the frequency domain and they're units of power. And so it represents the amplitude of the electrical impulses. I personally, that's the first thing I look at are my power levels. You know, I look at my hrv, I'll look at the rmssd, but really the power levels to me are significant. And I've been studying this now for years. And you know, with a multitude of people analyzing everybody, power levels are really important. I can tell when someone's depressed. I can see it. I can see it in their power levels.

What do you see when someone is depressed?

They're low. The power levels are very low. And they may Be balanced. That's the thing. The standard states that any ratio below two means you're balanced, you have a healthy stress level. I personally have found that I don't get concerned about a client's ratios until it's like an 8 to 1 or a 10 to 1 ratio. And then, you know, they're pretty much redlining all the time. But, you know, your sympathetic nervous system is your juice, and you want to use your juice. You know, you want to make sure that that is strong also. So my personal feelings are balanced, maybe slightly overrated. And as long as it's not an outlier, like a 10 to 1 ratio, I think it's okay. It's good to keep an eye on, though. And if you see a day where your LF is definitely way higher than it normally is, make note of that. What did you do? What didn't you do? Men have a tendency to be much more sympathetic dominant than women. And in fact, one of the things we do is you can set a stress sensitivity level when you're running your sessions so the breath pacer doesn't come up. Is what we found were some people were just red all the time. You know, they were always sympathetic dominant. And the whole point is to see a change, to create an action and to see a change in results. And if you're redlining all the time, you're not going to be able to see if anything is working. So we can actually reduce sensitivity on those kind of people. And it's selectable by the user.

Okay, got it. Now, in terms of the morning measurement, when I'm laying in bed in the morning and I take my HRV and my HRV is, let's say, slightly lower than I want it to be. And I decide I'm going to game that number, right? I decide I'm going to close my eyes, I'm going to meditate, I'm going to breathe, I'm going to do like a quick coherence technique or something like that where I imagine something I love or something I'm grateful for and put it on my heart. And I do all these things and I'm actually laying there in bed gaming the number. Does that affect anything at all? Like, can you actually do that, get out of bed and then train or do a hard workout? When you woke up and your HRV was low, but you did some kind of breath work or something to make it high, is that just like a temporary fix or does that fix it for the rest of the day?

Well, I think you would have to look at yourself and do that several days in a row and see if it actually is increasing your HRV throughout the day. Because, oh, yeah, you can game this. Your respiratory sinus arrhythmia. Every time you inhale, okay, your heart is going to increase, your heart rate is going to increase, and when you exhale, your heart rate is going to decrease. So right there, when you're doing rhythmic breathing exercises, it is going to affect your HRV values. And in fact, sometimes if it's very rhythmic, you'll see that your LF increases. When you're in a state of coherence, which is 0.1, everything is at that frequency. And what people don't know, we really don't talk about this a lot, just for simplicity, but your parasympathetic actually does bleed over into the LF frequency range. But for simplicity's sake, we say alpha sympathetic HF is parasympathetic. So I would see if your morning meditations increase your hrv and if in the next morning your HRV is higher, keep doing it, because all those things are really good. But yeah, definitely don't fool yourself by doing things such as breathing in a certain pattern, saying, oh, hey, look, my numbers are great and going out. The best thing to do is when you're just breathing normally first thing in the morning before you get out of bed, then we'll be able to see the true state of your autonomic nervous system.

My own finding is that I can slightly raise that number when I'm doing, like, meditation, gratitude, really focusing. If my HRV is low on breathing and breath work patterns to get it high. But I've found that if I wake up and it truly is low, and it's not low because I woke up to a phone call or an alarm or something crazy going on like a goat giving birth, then really the low heart rate variability is a true reflection of overtraining or overreaching or the need for it to be an easy day. Even if I can temporarily kind of game it up just a little bit higher in the morning, I've found that if I personally push through that multiple days in a row, it does. And this is why I first started measuring HRV in the very first place. As a thing I do every day, it does result in me getting ill or getting injured within a few days. So I don't push through. I pay attention to that number unless I happen to be super stressed out that morning from something that happened acutely. Right. Like right when I woke up. So that's been my experience now in terms of a high hrv, is there any time when you do a very high HRV or when you get a very high HRV that that would be a bad thing?

Yeah, it could be indicative of a bad signal. Bad signal quality, okay. Can give you a false high HRV. Arrhythmias. Also, PVCs, PACS, AFIB is going to skew those numbers and PVCs will give you a false high. Also, My husband has PVCs. He was an athlete too. And he has about three, three per minute. And I can see them actually happening. If your HRV is suddenly very high one day and you don't really understand why it's high, definitely look and see the ECT label I have on the monitor screen. So on the monitor screen you're going to see ect. I've started to show the user's ectopic beat. And I've always looked at ectopic beats.

I never saw that screen. So as I'm scrolling through, so you're.

On your stress monitor page.

Right. That's where I'm at right now.

And you'll see signal, and you'll see your four little dots. That's your signal bar. And then you'll see that you're an ect. So after a while, I decided to let the user see how many ectopic beats they were having. And I think this is important. Now everybody has ectopic beats. It's a very normal, natural thing. But if you see too many ectopic beats, there may be an issue going on with your heart. There may be an issue with the signal quality or your strap. An ectopic beat. I filter ectopic beats out per the standard. And what I look for is, is this beat under inspection a percentage higher than the average of the high or lower than the average of the low beats. And if it is outside this range, I take that RR out of the array. So the calculations are not performed on ectopic beats because once again, it would skew the results. And this is defined by the standard. This is why the filtering.

So if I look at that ect, I can actually tell if I have like paraventricular contractions or something like that.

That maybe I, you know, I can tell if I look at your rrs and I look at what happened with the filtering algorithms, because I can see if the RR was the instantaneous rate would have been above 200 beats per second or per minute or below, let's say 30, then we know that's an electrical artifact. But then in the middle, when you have these ectopic beats, I can look closely and I can see people that are suffering from PVCs. And I always recommend that they get a good ECG baseline.

Okay.

And in fact, in fact, there was one circumstance with an Olympic hopeful. She had contacted me for some reason, and I looked at her HRV and I said, wow, this is high. She's doing great. And then I actually looked at her rrs and I called her immediately because I could tell that her rrs, it just wasn't right. There was something going on. And I called her and I said, have you had an ecg? And she said, no. And I said, well, you know, I think you should get a baseline. I don't want to alarm you, but I'm seeing some abnormalities. And she said, you know, it's funny you say that, she said, because I passed out when I was in high school and I had a Holter monitor on for 24 hours. She said, but I gotta ask my mom what. What happened with that? It's like, put your mom on the phone right now. Because I could see there was something going on. And, you know, we do have circumstances where our young athletes are dropping dead on the field, and it's really important to know what's going on.

And this ECT screen can be used to elucidate a little bit of that.

A little bit. Just a little bit. Okay. So, you know, I'm not business of.

Diagnosing stuff, but basically, if you have electrical abnormalities or arrhythmias, should you even be taking HRV in the first place? One of the reasons I ask you about this is like, I interviewed Mark Sisson on my show last year, and he mentioned how he doesn't really use HRV much because of cardiac arrhythmia issues. Is it just something that can't give you any good data at all? If you have cardiac arrhythmias, it can't.

Give you any good data.

Okay. No, good to know.

You really shouldn't if you do have a lot of PBCs or if you have PACs. Now, what's really interesting is I have a lot of clients that have afib, and we use the product and I analyze their data. In that circumstance, I want to look at raw data. I don't filter anything out. And it's amazing to watch this person going into AFIB and, you know, predicting about a minute or two before that they're going to start into afib. And then potentially what they can do is they can take some type of preventative measurement to try to stop the afib from occurring. So in that circumstance, yes, you can use it, but it's not like your typical, what's my HRV number? Am I in a good range?

Okay, got it. Now, what about with, for example, when the HRV is very high? There is some chatter out there about the fact that that could be an indication of aerobic overtraining. Have you seen this? Like, too much parasympathetic stimulation?

No, I haven't heard of it as too much parasympathetic stimulation, but it could potentially be an enlarged heart.

You mean like ventricular enlargement due to.

A lot of training due to overuse.

What they call athlete's heart.

Athlete's heart, yes. You know, your heart is a muscle, and we see a lot of that where the heart actually enlarges.

Interesting. Okay. And that's something you can actually measure. I've actually had that measured myself via what's called a cardiac ultrasound. It's. It's. That's not the exact title of a ventricular ultrasound, something like that. There's some. Probably some cardiac physical therapist or nurse wanted to jump through the podcast and put the words in my mouth right now, but ultimately it's an ultrasound measurement that you can do. And I went into the clinic when I was writing my book Beyond Training, a big chapter on. On heart rate training and how to tell if you as an athlete as damaged your heart. Heart. And it was an ultrasound echocardiogram is what it was called. And that was followed up with an EKG stress test. Two things that I think you can do. And I did that to find out, a, did I have athlete's heart? And B, did I have these paraventricular contractions or these electrical abnormalities in my heart like you asked about PVCs? Yeah, yeah. And I turned out to be fine. I didn't show any more enlargement than you would expect in an athlete. And I did have some PVCs, but a very, very high. High, like 120% VO2 max on a treadmill, which is, I think just about everybody has a PVC when they're about to fall off the back of a treadmill. But ultimately there is one article that is out there on the Internet called Interpreting HRV Trends in Athletes. High isn't always good and low isn't always bad. And what it says is that a very high HRV could be reflective of excessive quality cardiac parasympathetic modulation, meaning aerobic overtraining. And I've actually seen this before, Jo Beth and some marathoners and triathletes who are using like this kind of maffetone style training and doing a. We're talking like three to five hours of aerobic work every day. I've seen very high HRV values and specifically extremely low. It would be hf, low HF power, low aerobic power, or low parasympathetic nervous system power from almost like an overtrained parasympathetic nervous system. And the hrv, for some reason flags is very high in these individuals. And so I have to step back and look at their training to determine whether that high HRV is because they really are healthy or because that high HRV is because they've been doing a lot of aerobic over training. And I can send you a link to that article if you want to look at it.

I would love to.

Yeah, yeah, I'll put it in the show notes for those of you who want to read it too. But that's, that's one thing to bear in mind. If you're just doing. And these are mostly like pro athletes, we're talking about people who are doing a ton of aerobic training. But it does turn out to somehow influence that HRV. And who knows, maybe they have some PVCs or some of this enlarged athlete's heart from all the training as well, and that might be going hand in hand along with that.

That's why it's good to see your cardiologist and just get a good baseline so you know where you start. Because PVCs are normal too. I mean, healthy people have PVC. The question is, how many do you have and does it cause any other issues?

Exactly. So you've also got the food test on this app. So when I push food, it can measure my morning pulse and then it has me measure my heart rate after a meal. How is that working exactly?

So what we did was we implemented Dr. Kocca's food sensitivity testing. Dr. Kocca was a famous endocrinologist back in, in the 50s.

That's C O, C A. I believe.

It'S C O, C A or potentially C O, C O, A. Okay, not sure about, but just you can Google Dr. Coca. So in the late 50s, he developed this very simple test to see if you were reacting to a food. And so we implemented Dr. Koca's test. And what happens is, you know, you tell. It'll measure your heart rate before you eat. You let the app know when you finished eating, it'll take another measurement and then 30, 60, and 90 minutes later, it will take a heart rate measurement. If your heart rate has increased over 16 points from your starting baseline heart rate, you're reacting to something.

That's it.

And it kind of makes sense.

So it's. It's not really using heart rate variability, it's just using heart rate.

Not at all. Just using heart rate.

How come you wouldn't use heart rate variability? Just to play devil's advocate, why wouldn't you look at, say, like, a rise in. In sympathetic nervous system activation or a drop in heart rate variability? Is it because there's no actual data?

No. You could, but I think heart rate is just so simple. Why make it more complex? I mean, what we do know, what's really interesting is after somebody eats, their sympathetic nervous system will increase significantly for a couple minutes. Sometimes it's only three minutes. In people who are obese, their sympathetic nervous system does not activate after eating. So, you know, there's lots of studies. We're all pioneers in this area anyway, right? We're learning things every day. But I thought that was interesting. The heart rate is a very simple way to measure if you're reacting to something. And it's pretty intuitively obvious, too. If you eat something and you're just relaxing, and 30, 60, 90 minutes later, your heart rate's up 22 points. I mean, that's what happened to me. I'm wheat sensitive, and I tested it, and I'm just relaxing on the couch. And I believe after 60 minutes, my heart rate went up 22 points. So that's significant. I mean, you say, hey, you eat something, your heart rate goes up, something happened, you're reacting. That's the Dr. Kocus pulse test.

Okay, gotcha. And that is something that then I can keep that data on the app, have a history of it, and I know that that particular food has rapidly increased my heart rate.

That's right.

Got it.

And then you can do more investigation.

You know what I found out, which is really interesting? I used to do a whole bunch of fats and proteins with my afternoon lunch, like sardines, seeds, nuts, steaks, leftovers from the night before, et cetera. And I would always feel crappy after lunch. And I started using this food sensitivity test, and I noticed that my heart rate was rising after lunch, and I would get really fatigued, and I'd have to take, like, this intense afternoon nap. And I still love an afternoon nap and an afternoon siesta, but I'd rather take it because I want to push the refresh Button not because I feel like crap after lunch. So I instead started actually doing for lunch exactly what I do for breakfast, which is just like, like a giant green smoothie with a little bit of ice and a few little superfoods in there. And all of a sudden I feel great after lunch and my heart rate doesn't go up like that. It's really interesting. So it appears that eating a copious amount of plant matter covered in oils and proteins for lunch doesn't really do my body any favors. And I use this coca pulse test on this app to actually begin to delve into that and figure it out so you can learn some interesting things. Even though it's not using HRV per se, it's a cool little feature of the app. So I dig it.

That's why we added it.

That's right. Okay, so in addition to the food test, there is another screen on here you've got your history screen which shows you all your sessions, all your charts, all your food intake. But then there is the correlation screen. This one can be a little bit confusing in my opinion. Can you walk me through this correlation screen and how that is used? Sure.

So I designed and developed the correlation screen because we wanted to see if there was actually a correlation between your other biometrics and hrv. So this is a one to many correlation. And what you can do is you can download your Fitbit data, your withing's weight data, your withing's blood pressure, your mapmyfitness data, your steps, your calories in, your calories out, and then look and see, is there a correlation between my HRV or my stress levels or even my blood pressure and all these other biometrics that we're gathering using other vendors devices like the Fitbit.

Can I use the Oura ring on this?

No, they don't have an interface yet.

Okay.

That I can download.

We should talk to them about doing that because like that's probably the one self quantification tool that I use the most aside from the naturebee app.

You know, I have talked to him because I use the Oura ring also and you just can't get the data from it.

Okay, after we record this. Sorry, for those of you listening in the boring opening the kimono to the discussion, let's talk to them. After we record this, I'll shoot an email over or something and we'll see if we can make it work. Because I didn't realize that we could bring the aura data into this.

Theoretically we can bring any data into it. It's the API. They would need to have an API that I can access and get their data.

Okay, got it.

I know this is a very, the correlation, it's very powerful and it's complex and it's a little too complex. I made a mistake. It's so powerful I let you do so many different things with it. But because of that, if you ever look at any of these screens and you see that little film clip icon I performed, I created two instructional videos to walk people how to use the correlation screen. And so what you can do is you can go to your settings and you can select what metric you want to be. Your major, your one to many metric. You can also then select your data and you could, you can filter this out any way you want. You want all your Fitbit, you just want certain things and then you have the ability to select your date range. You can even select a range that's maybe five days prior to a certain date. And then you say go, you go back, you refresh your screen. I'm going to go out, I'm going to ask Fitbit for all your data. Why things map my fitness, whatever you've requested and then perform the correlation and you'll see if there's a positive correlation or negative correlation. The larger the bubble, the higher the correlation. Also, what's really nice about this, what I really like is if you swipe the screen, you're going to see all of the bubbles under available data. And if you do a long press on any of those bubbles, it actually gives you a list of the values.

I just turn, pressed and long press. That's pretty cool.

I love that. And then you can just keep swiping.

Yeah.

And it'll go through all the tables. I love that because I've been measuring my weight with widing scale for years. Right. So here I have this one perfect list of my weight from the beginning of time. And so it's a nice place to collect data. And then you just tap back and you can go back to the screen and it can show you what's activated. So keep swiping. So I agree it's complex, it should have been simpler. But we wanted people to see if you've got a race and you just do great that day, you can go back and what was I doing? What were my other metrics? Is there a correlation here between my HRB and my calories in or my mets or even my blood pressure?

Right. I like that.

That's okay. That's the correlation screen. A lot more people don't appreciate how powerful it is and it's difficult to use.

I agree. Yeah, no, but it makes sense now. It makes sense the way that, the way that you explain it. So it's basically just a way to, to loop in the data from other self quantification devices and see how that correlates if it does the correlation screen to your actual HRV or if it correlates at all. Now another question for you. I've been using the chest strap called the VIVA V I I I V A is how it's spelled and actually if you, if you go to the show notes, I'll show you a list of all the different heart rate monitors that are compared to compatible with this Nature Beat app. But I think that was based on your recommendation and the way that I understand it is some Bluetooth heart rate monitors are more accurate than others. Is that true?

Yes, that is true. All of the Bluetooth heart rate monitors though that we have on our supported products page, we have tested. So those are all very accurate.

So Polaris, what makes them more accurate?

I would say what makes the others less accurate. And it's just going to be the design, it's going to be their filtering. Not all heart rate monitors are built and designed the same way. And some people, we really need accurate RRs that's, you know, that's critical for.

An accurate Rs being the amount of time in between each beat of your heart.

That's right. So what I get from the chest strap, you'll get two things from a chest strap you can actually get more than that. But if you put on, let's say your Polar or your Viva chest strap, it's going to transmit through Bluetooth your heart rate, your average heart rate. So I get that number how many beats per minute and if I set it up in the appropriate mode, it will transmit to me the intervals between your heart beats. Right. So that's your RR interval from the QRS T series. If you ever see an ecg, that's that bump up, it goes down and up and down and up. That's the R. So we measure from R to R and the polar chest strap will give me, or the Viva chest strap will give me this array filled with the time intervals, it's you know, N minus, N minus one.

Okay, okay, got it. Now, in terms of that particular heart rate monitor that I use, it's the viva. And then what I do is I actually keep next to my bed the electro. I used to spit on the heart rate monitor and now I Actually have like a little squeeze bottle, this electrode gel. It sounds laborious but honestly this takes me like 10 seconds when I roll over and do it. And then I just, I use my gratitude journal. I, I do the HRV measurement and I lay there and so I've found that when I combine the gel with that Viva heart rate monitor and again I'll link to which one I use in the show, notes that it's incredibly accurate. I never get that, oh, you lost your heartbeat, can't find your heartbeat, lost the connection. Nothing like that happens. So that's the one that I like. And it works well for if you're going to measure during exercise or during a day, if you want to see how your stress is during the day as well.

The electro gel is important. The contact with the pads is so important. To get a good signal I have to use electrogel or I can't get a signal at all. Some people are okay. You know, ironically spit is probably one of the best conductors because it's coming from your own body. But the electrode gel is easy and it's really expensive.

Yeah, I use the Spectra electro gel. It's like the stuff if you go to Amazon, it's the top one in Amazon. That's the one that I get and works better than spit and frankly doesn't smell as bad as spit either. So. Okay. There is this new thing that you had me using for a while that I still own that talks to the nature beat and it works without a chest strap, this thing called a zoom. Can you fill me in on this?

Yes. So just a little bit history. We've been looking for a non chest strap solution. So this chest straps use electrical signal, right. To detect your heart. Just like an ECG does. It uses electrical signals where the zoom and any other wrist worn devices or anything you clip on your ear or you put on your own arm is going to be using a technology called PPG and that's photoplysmogram. It's a really tough word to say, Photoplysmogram. What PPG is, is it's going to detect, you know, your cardiac cycle. Every cardiac cycle is going to pump blood to your peripherals. Okay. So it uses LEDs to illuminate the skin and then the light either reflects back or is transmitted through the skin. And it will detect, it's in essence looking at changes in color. So as your blood pumps out really with the volume and then comes back. And that's how any ppg, it's like a pulse oximeter. You've been in the hospital, they put that little thing on your finger.

Yeah.

They can see your hemoglobin, they can see your pulse. That's exactly what it's doing. It's looking for changes in blood volume and, in essence, color.

It's testing your actual change in blood volume based on color.

Yeah.

And how is that related to heart rate variability?

Well, what you can do. So what it's trying to detect is wonderful and historically has been wonderful for an average heart rate, because an average heart rate doesn't really need to be all that precise when we're talking about heart rate and variability. Those RRs, I need precision down to the microsecond. 000,000. Right. So I need precision. And you can imagine that if you're looking and looking for changes, that it's going to be a lot more difficult to try to figure out exactly when that heart beat. Okay. That's why the electrical has been so, so great. Right. It's very accurate because we know exactly the second that it beats because it's giving out electrical signal where here they're sort of guesstimating and they have to use some really complex filtering formulas and algorithms. And we knew that sooner or later these smart people would eventually figure it out. We had worked with some of the best companies to work with them on their algorithms to try to get this PPG more accurate, and it just hasn't really happened until now. And LifeTrak contacted us and they've been working on this for years, and their product is very accurate in the closest thing that we've seen that will come to electrical signals.

So basically, it's called a zoom. And you wear it on your wrist.

Yep.

Okay. Now, the interesting thing about it, I think, aside from the fact that it also measures the amount of blue light exposure that you've been exposed to, which I just think is a very, very interesting aside, is from what I understand, because this is the first thing that I asked you, it actually does not constantly transmit a Bluetooth signal when you wear it. So it can measure HRV and could even measure HRV during the day without, unlike a Fitbit or a jawbone, constantly transmitting a Bluetooth signal all day long.

Well, yes, yes and no. It doesn't transmit a Bluetooth signal. It doesn't announce to the world like your chest strap is always going to be announcing, hey, I'm here, I'm a chest strap. Hey, I'm here. I'm a chest strap. You know, do you want to pair with me because of power constraints, with the watch, they always try to conserve power. Transmitting uses up a lot of power and so it will only transmit Bluetooth if you've set it in streaming mode. So let's say you are exercising and you want to see what your steps are. You can actually stream that to your phone if you set it in that fashion. Or if you double click on the face of the watch, you tap twice, quick succession, then it will transmit rrs and that's when the nature beat will see it. And it transmits RRS for three minutes.

Okay.

And then it stops.

And how is it measuring my actual amount of blue light exposure? I don't know because I think that that's really interesting to be able to. I noticed that it's complete aside and it doesn't really have much to do with heart rate variability, aside from my feature. I guess the fact that excess artificial blue light or lack of sleep from excess artificial blue light is obviously going to affect your hrv. But I thought it was just so interesting. I've never seen a self quantification device that will tell you, oh, hey, you're getting too much exposure to artificial blue light.

And I'm pulling it into the app too, because I can get that data from the zoom.

That'd be interesting to see if too much time spent in the shopping mall can affect your hrv.

You know, I don't know all that much about blue light. I am getting the data from them. It's, you know, it's relatively, it looks relatively accurate, but I just don't know how they're doing it.

Interesting. Okay.

But it's a really nice product and these are really smart guys and we have enjoyed working with them.

I like it. I told you though, I haven't been using it that much. And one of the, one of the reasons for that is because I journal when I'm taking my heart rate variability and I've found that I can't turn the pages or write in my journal because you got to keep your hands stoked. So I still use the heart rate monitor.

Yeah. One of the things is you have to sit still. No talking, no turning your head, just sit perfectly still for three minutes to get an accurate measurement. And if you are using the zoom, one of the things you want to do is to go to the real time instantaneous RR screen and see if you're getting any red spikes. If you're getting red spikes, that means that it's not able to pick it up. You're getting electrical artifacts, so you want a really nice clean signal. Everybody's different too. And so, you know, it may work better on some, it may not work as well on others, depending. I love it. I love getting away from the chest strap and it's, you know, very easy to use.

Got it. Okay, cool, man. There's a lot here from the Naturebeat app to this LifeTrak Zoom HRV monitor, which I think actually is, is pretty useful unless you're like, you know, I can use it different times during the day, I just can't use it for that morning reading. But it's better for like the, you know, doing a workout in the gym, that type of thing, this Zoom HRV monitor, but the correlation screen, the food screen, the four different options for monitoring stress. And by the way, for those of you wondering, I use the HRV for training one and then how to actually read your data. It's just such a useful tool and I'm, I'm really glad I was able to get you back on Jobeth to kind of dive into some of the specifics of this stuff and revisit some of the things that I really wanted to make sure people were aware of when it comes to. Again, one of the few things that I self quantify every single day. So for those of you who have been listening in, I'm going to put a link to everything we talked about in the show notes. If you go to BenGreenfieldFitness.com HRV too. If you want to take the deep dive and you want like the equivalent of a university education in heart rate variability training. I've got 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 different episodes and articles in addition to the one that you're listening to right now that talk about everything I've personally discovered when it comes to hrv. So there's plenty in the shownotes. And again, Those are@BenGreenfieldFitness.com HRV the number two. Joe Beth, thanks so much for coming on and sharing with us all these different things that the Nature Beat app can do and all the latest in heart rate variability training.

Well, thank you. It's been a pleasure, Ben.

Awesome. All right folks, well, until next time, I'm Ben Greenfield along with Jo Beth Dow from Sweetwater Health signing out from BenGreenfieldFitness.com have an amazing week. 3, 2.

You've been listening to the Ben Greenfield Fitness podcast. Go to BenGreenfieldFitness.com for even more cutting edge fitness and performance advice.