HRV and the Self-Rated Health Scale

by Dr. Chris Hardy on September 8, 2016

HRV and Self-Rated Health

This is the fourth in a series of articles developed from Dr. Chris Hardy’s live presentation at Dragon Door’s Inaugural Health and Strength Conference. Click here to read the first article of the series.

In the previous posts of this series we were estimating the size of the stress cup. But, there’s a more reliable way to measure it. We’ll use the interrelationship of the brain, the cardiovascular system, and the musculo-skeletal system for another window into the stress cup. The first window is heart rate variability, the beat to beat variation of the heart rate.

We will use HRV as a window into the autonomic nervous system and how it relates to the heart. This will show us the stress load on a given day. On a high stress day, the sympathetic nervous system is dominant—the fight or flight system will drive the heart with a machine-like precision (low variability). This indicates a state of allostatic overload, poor health, and an overflowing stress cup.

Caption: In this chart, the beats are the same distance apart. That machine-like precision is not good. It's a sign of bad health and stress to the system.

In this chart, the beats are the same distance apart. That machine-like precision is not good. It’s a sign of bad health and stress to the system.

Now, in the normal state—when you have good readiness and a manageable stress cup—you’re in parasympathetic dominance and will have that good, high variability.

In this chart, the time between each beat is slightly different. That's how a healthy heart and nervous system actually works. It's imperceptible, but if you measure it accurately you'll see the variability between beats.

In this chart, the time between each beat is slightly different. That’s how a healthy heart and nervous system actually works. It’s imperceptible, but if you measure it accurately you’ll see the variability between beats.

There are several apps that calculate HRV and will give you a score. There’s also a section in Strong Medicine that shows you how to do that in training. It’s a very simplistic approach, but its good for our purposes.

Joel Jamieson, a Seattle area MMA trainer uses HRV in training in a very sophisticated way so definitely look him up if you want to learn even more. But, I prefer a more simplistic and intuitive approach. But, before I show you my approach I want to quickly review another simple way to assess the state of the nervous system.

MiniHomuncDiagA homunculus is a representation of what we would look like if we were physically configured according to the proportion of brain required to operate our body parts. Do you see how big the hands are? A huge portion of the brain is involved with the sensation and motor control of the hands. For example, grip training has a huge impact on the nervous system. Grip strength is also a good way to tell the status of the nervous system. This idea has been used in the former Eastern bloc countries for a long time, and Charles Poliquin wrote about it pretty recently.

Charles Poliquin’s protocol starts with recording a baseline using a Dynamometer. You can get them pretty cheaply on Amazon. Be sure to measure grip strength in kilos when you (or your client, if you are training others) are feeling good. Then on the morning of training, measure it again, and if you drop 2kg, then you may want to reconsider training. If you drop 4kg from the baseline, then you might even consider taking a rest day. it’s a simple way to do it. Do you have to continually measure grip strength or HRV with all your clients? No, that would be ridiculous, fortunately there’s another method.


The Self-Rated Health Scale

In terms of predictors of who will develop chronic diseases, and who is at risk of dying, what is the best marker to use? We’ve used all kinds of blood tests, and every other imaginable test, but the best predictor we’ve found is to ask this one question:

“In general, would you say your health is on a one to five scale? With one being the best and five being the worst?”

Believe it or not, that self-rated health question was more accurate than any medical test in predicting if someone would develop a chronic disease in the next 5-10 years. There’s a new area of neuroscience intensely studying interoception, the brain’s subconscious awareness of our organ systems. Many of you who read Strong Medicine know that our gut and intestinal tract has just as many neurons and nerve cells as the spinal cord. Some even call it the “second brain”. When you have a gut feeling about something or butterflies in your stomach, that’s the brain actually monitoring the state of our organ systems on a subconscious level. It can also induce stress responses, which is why diabetics have an on-going low-level “fight or flight response” due to this interceptive process monitoring the state of the internal organs and immune system. The brain knows something bad is happening and that we need to be on alert. This system also gives you an intuitive sense of how you are doing.

A new study came out about HRV and focused on measuring what correlated best to Self-Rated Health. We already know the question predicts disease very well—they measured every blood test, cholesterol, inflammatory monitors, and many other tests, but what correlated best with Self-Graded Health was heart rate variability. People with high HRV (good) usually said that their health was about 4-5 on the scale (the highest health scores). So, how you intuitively feel physically and mentally is very predictive of your stress cup. This is why an intuitive approach to a given day’s training could be very valid. Even though there are some really sophisticated tools such as the Recovery Stress Questionnaire For Athletes—which is a validated tool—I guarantee that none of your clients will want to sit down and answer 76 questions.

If you’re training elite athletes, it’s great, but it is not practical for those of us in the trenches. My next suggestion is not validated, and I haven’t tried it out—so you can be the test group—what if we replaced the Self-Rated Health question with the following:

“In general, would you say your readiness to train is… excellent, very good, good, fair, or poor?”

I would also suggest verifying it by testing grip strength and heart rate variability first before asking the question to see how they correlate. Over time it will help them get an intuitive sense of how they are and fine tune their conscious awareness of interoception. So, when they give you a rating, you can also look at the data (grip strength and HRV), and over time this will be a pretty good window into how they’re doing.


Getting Your Clients Onboard with Smart Programming and Recovery

How do you convince your client that this stuff really matters? It’s essential. If you want to train hard, you’ve got to recover harder. You need to tell your clients that they need to reduce their stress cup and earn the ability to train hard. The results they want will only happen with a proper balance of training and recovery.

The first thing they have to fix is their sleep, and there’s a whole chapter in Strong Medicine about doing that. Stress management, meditation, yoga, whatever you want to do is fantastic. Massage and acupuncture are unbelievable for helping to reduce stress and enhance the parasympathetic nervous system. If you like qigong, tai chi, all that stuff is fantastic as well to achieve the same goal.

Obviously, cleaning up the nutrition is a whole lecture into itself. As is feeding your activity levels. If you are going to crush yourself with high intensity training, you need to replace that muscle glycogen. If you’re only doing a walking and strength-based program, you can go very low carb and be fine. But if you want to push that anaerobic threshold, then you will need to feed that activity or you will overtrain.



First, estimate their stress cup size. Then, estimate what is filling it today, since it will be different that what fills it tomorrow. Then, we will prescribe an appropriate exercise volume and intensity—and that’s what you guys as trainers know how to do well already. Now, you have the extra information to help you adjust the sets and reps, intervals and modalities. And while you don’t have to assess the stress cup every time you train your clients, I think you should always ask the self-report scale question and then prescribe the appropriate amount of training.

I don’t think you need to use HRV on the average client. But, if you are working with elite athletes, you will need to cover all those bases. The most important thing for everyone is to always emphasize the importance of recovery.

Now, using this approach is very simple, and I provided the scientific foundation for how we came up with this very easy system. If you train someone this way, they will meet their goals. It will be sustainable, unlike those three or four weeks crash diets and radical exercise routines. With this method, every New Year, instead of starting over with a resolution, they can just continue building on the success of the previous year. This is just a framework, so use your expertise as a trainer to customize your programs.

The final post in this series will be the best of the question and answer portion of Dr. Chris Hardy’s presentation.



Chris Hardy, D.O., M.P.H., CSCS, is the author of Strong Medicine: How to Conquer Chronic Disease and Achieve Your Full Genetic Potential. He is a public-health physician, personal trainer, mountain biker, rock climber and guitarist. His passion is communicating science-based lifestyle information and recommendations in an easy-to-understand manner to empower the public in the fight against preventable chronic disease.


Strong Medicine: Burst Cardio Protocol

This is the third in a series of articles developed from Dr. Chris Hardy’s live presentation at Dragon Door’s Inaugural Health and Strength Conference. Click here to read the first article of the series.

The Stress Cup dictates the beneficial, hormetic exercise dose. To apply this concept to our training, we need a scientific foundation—but it’s also an art. Elite coaches like Marty Gallagher—who has coached for over fifty years—have intuitively figured it out. In this article I will try to give you a foundation so that you won’t need all those years of trial and error to figure it out. Applying this science to your clients is the art of training. Since you already know how to adjust sets, reps, intensity, and volume, you’re already ahead of the game. We will try to hone your art with these concepts.

First, there are no hard and fast rules, this is more a conceptual thing. Remember that all of your clients are individuals and can’t all train the same way. Plus, their environments and stresses change from day to day. Our approach will allow for this day to day individualization.

Case Studies:

Our first example is someone with a “tall” stress cup. What’s filling his stress cup? On new client intakes, do you ask about their health problems? How about their stress levels and how they sleep? It’s really important that they tell you about these issues. This client has a small stress cup and a large amount of lifestyle stress will put him in allostatic overload. We will know that he’s been in this state for a long time if he has a disease resulting from a failure to adapt. Diabetes can be thought of as a failure to adapt to a lack of exercise, poor sleep, and/or terrible nutrition. The body will try to adapt to those stresses, and even though it does bad things for the body, diabetes is actually an adaptive condition.

Stress Cup Size Chart

So, how would we train this client? What would we do for strength training and for cardio? Like many other people, our client also doesn’t have a lot of spare time. One approach to consider for a guy like this is a stripped-down linear progression with a bit of a hypertrophy bias, in the 5-10 rep range. Diabetics and people with metabolic diseases work very well in that range and it helps clear out some muscle glycogen too. It’s beneficial, but it’s not the only way.

Let’s assume for example that he has diabetes and high blood pressure. Of course he could be walking but we could also try high intensity interval training—even low amounts of it can have incredible results for diabetics. Basically, it bypasses the normal insulin signaling mechanisms and gets some of the glucose from the blood stream back into the muscles. Emptying those glycogen tanks is really beneficial too, because lower glucose in the muscles will pull a lot more glucose from the blood. This process will increase insulin sensitivity for at least 24-36 hours.

Burst Cardio Protocol Chart

But, while high intensity interval training is a really good approach for the diabetics, our example client also has a small, and nearly full stress cup. We need to figure out how much exercise is too much. With our example client it would be very easy to overdo it, so we need to remove the guesswork. We will use the Burst Cardio Protocol we describe in Strong Medicine. You don’t have to use it with all of your clients, but it is a fail-safe. When working with a client who is at risk of exercise overdose, but who could really benefit from high intensity training, the Burst Cardio Protocol is a very good choice.

This protocol uses heart rate to set both the interval duration and recovery times. Depending on the state of the client’s stress cup, they will respond to the same exercise differently from one day to the next. Heart rate response will be our window to the state of their stress cup. We will start with heart rate max, which is not the most scientifically accurate, but will be a close enough estimate for most of you clients. So, we’ll start by leading them to warm up, then we will start their interval exercises as hard as possible. The goal is for them to reach 95% of max heart rate, though 90% is the requirement. Once the client reaches the heart rate goal, they stop and recover until their heart rate is back down to 70%, then they begin another interval. This works well for a 20 minute session and can be done with kettlebell swings or snatches, or other modalities like the hand bike, elliptical machine, medicine ball slams or even burpees. You can choose anything anaerobic that will rapidly increate the client’s heart rate.

The key point of this whole protocol is that on the day when the stress cup’s load is low, there’s room for a higher exercise dose. Since a low stress cup equals parasympathetic dominance, this means the client will recover faster because the parasympathetic system will lower the elevated heart rate from the exercise. Faster recovery times will also allow the client to do more intervals during the set period of 20 minutes. If they are recovering more quickly, they’ll be able to start the next interval more quickly, too. When the stress cup is nearly full, there’s less room for exercise, and the sympathetic system is dominant. Recovery will be slower. If the client gets up to 95% and they have slept poorly, they will recovery more slowly since the parasympathetic system won’t be able to bring the heart rate down as quickly. The client will not be able to do as many intervals in the allotted time.

I’ve tested the protocol myself for a few years. One workout I tried a couple of years ago used the twenty minute time period. I did a hideous alternating combination of kettlebell snatches and medicine ball slams. It was rough. You can see on the chart below that I spiked up to 95% pretty quickly. I recovered and managed to get six intervals in 20 minutes—and that was on a day when I was feeling great.


I waited a week later and tried the same workout when I had had a night of poor sleep. When I did the exact same workout with the same time period, look what happened on the chart below! I spiked up to 95% again, but then it kept taking me longer and longer to recover. After the 4th interval, it took me so long to recover that I never dropped below 70% before the 20 minute session was over.


So, even though I had fewer intervals, the protocol allowed me to exercise but not overdo it. My heart rate was a window into the state of my stress cup and adjusted the number of intervals for me.

The Burst Cardio Protocol automatically adjusts to the correct dose on a given day. As another example, let’s say that I’ve done a strength training session before my burst cardio. The strength training will affect the nervous system, along with my recovery time and the interval itself.

You can also use the Burst Cardio Protocol to train multiple clients with different stress cups. One client may end up doing more intervals during the time period, but since they will be regulating their own intensity you can concentrate more on watching and coaching their exercise techniques. When one client wants to know why they are not able to do as many intervals as someone else you can also explain how recovery itself is a trainable event. Between the intervals we can also coach our clients with breathing exercises and techniques to help them recover. A simple breathing technique such as breathing in, filling up the diaphragm, then slowly exhaling while watching their heart rate on a biofeedback device will allow a client to feel like they’re still training while they are resting. This technique will help them recover faster, too.

The protocol also works for mixed modalities—clients can do kettlebell swings for one round, the elliptical machine for the next, etc. I’ve tested it and found that when someone gets to 95% with kettlebell swings, it takes a lot longer to get back down to 70% as opposed to getting to 95% on the elliptical. The Burst Protocol also adjusts for the given modality. While it’s not necessary to use the Burst Protocol all the time, it is very useful if you are worried about overflowing someone’s stress cup.

The next post in this series will cover another common training scenario and how to use HRV and the Self-Rated Health Scale.



Chris Hardy, D.O., M.P.H., CSCS, is the author of Strong Medicine: How to Conquer Chronic Disease and Achieve Your Full Genetic Potential. He is a public-health physician, personal trainer, mountain biker, rock climber and guitarist. His passion is communicating science-based lifestyle information and recommendations in an easy-to-understand manner to empower the public in the fight against preventable chronic disease.


The Stress Cup and Allostatic Load

August 4, 2016

This is the second in a series of articles developed from Dr. Chris Hardy’s live presentation at Dragon Door’s Inaugural Health and Strength Conference. Click here to read the first article of the series. The Stress Cup is a visual representation of allostatic load, the total amount of stress. In the example above, the cup […]

Read the full article →

The Mechanics of Stress Response

July 21, 2016

This is the first in a series of articles developed from Dr. Chris Hardy’s live presentation at Dragon Door’s Inaugural Health and Strength Conference. I was 23 years old and had graduated from one of the toughest schools in the military. It was designed to mentally and physically beat you down. After 5-6 months, I […]

Read the full article →

Building Your Health Fortress, One Brick at a Time

December 24, 2015

The New Year is almost upon us and millions of people will be making resolutions to improve their health. Gym memberships are purchased, new diets are tried, and home exercise equipment is ordered. Unfortunately most of these resolutions are doomed to fail, often by the time March rolls around. The gym memberships go unused, the […]

Read the full article →

Journey to the Center of the Physiological Universe

December 2, 2015

“We here in the Western world are top-heavy. ‘Shoulders back! Chest out! Stomach in!’ Thus the center of gravity becomes elevated. In zazen, Zen training, the tanden (or hara) is the source and foundation of deep meditation. When moving, the tanden is the source of bodily strength. Abdominal breathing generates strength: we live  from this […]

Read the full article →

Don’t Fear the Sleeper!

November 12, 2015

Want to lose fat and gain muscle? Want to improve your cognitive ability and decrease reaction time? Want to increase your ability to heal from illness and injury? Want to do it without taking expensive supplements or complicated diets? Sure, everyone does! Then let me tell you a little secret: Sleep is one of the […]

Read the full article →

Folding Inner Space, Part III – Pure Awareness and Deep Athletics in Action

October 29, 2015

Mark Chaillet, world record holder, world champion: Mark is shown in 1980 deadlifting 800-pounds. He weighs 219 in the picture and is badly out of position, struggling to finish the lift. His shoulders have gotten in front of the bar during the upward pull and now, with legs already straightened; he must finish locking out […]

Read the full article →

Folding Inner Space, Part II – Cessation of Thought and Super-Human Effort

October 15, 2015

Hormonal Nitrous Oxide Body-shocking physical effort, maximum effort of a very specific type and kind births an exercised-induced altered state of pure awareness that elite athletes routinely experience, yet fail to identify.  Access to this exercise-induced zone of pure awareness can only be attained when the degree of difficulty is sufficient to cross a hormonal […]

Read the full article →

Folding Inner Space: Part I – Iron Zen: Exercise-Induced Altered States

October 1, 2015

Tibetan Lama Dungse Jampol is the son of a Tibetan meditation master. At a young age he asked his father to explain to him, “What is the nature of the mind?” and “What is ‘pure existence” and what is the meaning of “enlightenment?” His father sat down and said to the boy, “Come closer.” The […]

Read the full article →