Heart Rate Variability and Interval Training With Dr. Eldred Taylor

When I implement a training plan for my clients, I do so with a sound understanding of their physiological needs and how certain exercises will help them. So when I find that there are additional benefits to my training methods, I am thrilled!

Recently I had the chance to sit down with Dr. Eldred Taylor, who along with his wife Dr. Ava Bell Taylor authored "The Stress Connection" and "Are Your Hormones Making You Sick?". Dr. Taylor practices functional medicine, which emphasizes maintaining wellness over just curing illness - something that I feel our current medical system often fails to address. The information he shared with me is available in an in-depth interview he did with the EliteHRV podcast, an informational podcast that focuses on the importance of understanding heart rate variability (HRV). I will link to that podcast at the end of this post.

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To summarize what I learned from our chat, heart rate variability is used as a measure of wellness by determining how quickly the body can respond to, and then recover from, a stressful event. Whether it's a loud BANG or another driver about to cut you off on the highway, your body will quickly and instinctively go in to "fight or flight" mode. Your heart rate will elevate and your stress hormones will begin to surge. What happens when the event is over - that can tell us how well the body's sympathetic and parasympathetic nervous systems are operating. On a more subtle scale, the heart rate naturally varies from beat to beat as it responds to seemingly undetectable changes that occur within our organ systems throughout the day. Again, how quick or slow the heart responds is an indicator of our overall health.

As Dr. Taylor explains in the podcast, he starts with measuring HRV with every client, as this will tell him what further investigations need to take place. And what he shared with me, is that high intensity interval training (HIIT) can help train the body to better respond to stress and then return to a restful state. This was very exciting for me, as I already understood how HIIT training can positively impact lactic threshold - simply put, how long the body can work through the "burn" of an exercise without going completely anaerobic - and that regular cardiovascular exercise can help lower one's resting heart rate. After listening to his podcast, I followed up with Dr. Taylor to learn more about the connection between cardiovascular fitness and heart rate variability.

In the fitness industry, we understand that interval training can help increase aerobic capacity and lower resting heart rate. Can you tell us how this type of training improves heart rate variability and why that is important for overall health?

Interval training teaches the body to respond quickly to a physical stress and quickly  recover from the stress when the interval of exercise is completed. This improves heart rate variability because it trains the nervous system to quickly respond to and recover from stress. When someone has been trained to respond to the stress of exercise the body can better respond  to emotional or job stress. Not only does the body respond better to emotional stress but to it will respond better to any imbalance in the body and re-establish balance.  This is why increasing heart rate variability is important for overall health. People that overreact to stress or let situations bother them for extended periods of time can benefit from interval training.

Do you use heart rate variability to make fitness training recommendations?

I do use HRV to recommend fitness training routines. When there is low HRV it is usually because the parasympathetic nervous system is low or absent. The body's number one job is to recognize an imbalance. If the imbalance is not corrected the sympathetic nervous system (SNS) continues to dominate  and suppress  the parasympathetic system until the stress is removed or the body has been able to recover.  A person should not continue to perform stressful fitness routines when their HRV is low. When the the sympathetic nervous system is taxed by overwhelming physical stress it can not pay attention to the small imbalances internally. These small imbalances can became large imbalances before the body recognizes them and the body is not able to repair itself. This is why when you overexercise your joints begin to break down and your immune system is weakened and you are likely to get sick.  Again, when HRV is consistently low, one must allow time for the body to recover. Interval training is best when a person is attempting to improve HRV after a period of rest.

You state in your podcast that funcational medicine addresses the gap between being completely well and having a disease - where many people seem to fall in today's stressful world. Why is it important for those starting a training program to consider seeing a functional medicine practitioner?

​It is important to see a functional medicine doctor  prior to starting a training program because you need to determine how well your body is presently functioning. For example, a very important test that we do in our office is *Bio-impedance Analysis (BIA). The BIA measures one important measure of health the phase angle. This determines how well someone is able to produce new cells to replace dying cells. This is very important because one does not want to start a strenuous training program and a restricted diet when they are already unable to rebuild and repair themselves. A person with a low phase angle needs to be counseled on how to improve nutrition, gut health and the importance of rest and sleep. These are the 3 components of health, a healthy diet, a healthy digestive system to breakdown the food and absorb the nutrients and sleep, to allow the body time to repair and rebuild. 

What training mistakes do you encourage clients to avoid?

The most common mistake I see is that when someone is working out to loose weight or to get more energy, when it does not work they do more of the same. This is not smart. If something is not working for you it important to do something different. Change your routine or look for reasons why the program is not working for you. 

Possible reasons:

• Hormone imbalances
• Food sensitivities
• Stress or increased cortisol
• Poor gut health​ 

Most people new to fitness want to workout 5 days a week and eat nuts and berries. Often the goal is to lose 30 lbs tomorrow. When the phase angle is low the results will be the exact opposite. This will lead to a frustrated client and a frustrated fitness coach.

(*Watch this video Dr Taylor recommended to me to better understand Bio-impedance Analysis and phase angle)

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Once a client has a good understanding of his current health and is ready to start a workout program, I use a variety of interval training circuits to enhance weight loss and of course, improve heart health. The most important thing is for these workouts to feel challenging, not impossible! As fitness improves, we gradually reduce rest intervals, or eliminate them completely as the resistance work becomes active rest. But effective interval training must be done SAFELY, so here is a list of my personal DO'S and DON'TS:

DO allow time for adaquate warm up and cool down! For an hour session, I have clients warm up for 5-10 minutes, allow time for rest intervals as necessary, and make sure my clients cool down and stretch before leaving.

DO fuel with proper nutrition. Generally, you can work out 1.5-2 hours after a meal, or 45 minutes after a good snack. Ask your trainer for suggestions based on your dietary needs. If you did not eat well the day of your workout, PLEASE tell your trainer! It doesn't make us look good to have our clients puking or passing out.

DO consider training with a heart rate monitor. Your trainer can help you determine your best heart rate range from recovery workouts all the way up to your most intense workout. And keep in mind, your HR Max is not absolute. The old myth that your heart will explode if you excede your max is untrue. The body will instinctively work to bring it back down; you'll either get wiped out and have to stop, or possibly throw up (not our goal!). Generally speaking, aiming for 80%-85% HR Max during intervals is ideal. The amount of time a client will work at the level varies by ability and fitness goal. Without a HR monitor, I recommend intervals feel tough enough that my clients want to stop once they are completed, but they don't feel like they are going to collapse.

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One of my clients doing a cardio interval exercise: Quicksteps for time (20s/side) while holding a medicine ball.

​DO NOT hesitate to tell your trainer if you ate or slept poorly before your workout. It is their job to modify your workout to make it effective so you can still enjoy some benefit from having showed up, even if you didn't feel fantastic when you arrived.

DO NOT pile on HIIT workout after HIIT workout. Your body needs recovery days! Otherwise you run the risk of overtraining, which has the opposite effect on the heart and can stress other organ systems. 

DO NOT compare yourself to others! Everyone starts somewhere and has different goals. Worrying about what the guy on the treadmill next to you is doing will just waste mental energy you should conserve to concentrate on your own efforts. But that being said...

DO look to others to learn and be inspired! Just because you can't do what they are doing does not mean you won't eventually get there. If you see someone working out as hard as you hope to some day, stop and ask them about their fitness journey. I am certain you will learn something fascinating about their experience and be inspired by their story.

The body is a complex system but when we learn to listen to it properly, it can tell us a lot about how we can best train to improve our fitness. I learned a lot from Dr. Taylor, and hope that if you are considering taking a big leap this year to regain control of your health, that you get to know your local wellness profressionals to help you along the way!

Dr. Taylor practices in Atlanta. You can find his website here.

And you can listen to his interview on the EliteHR podacst here!