Tracking your Heart Rate Variability (HRV) is a non invasive way to measure your readiness and fatigue. Knowing this will enable you to harness your body's natural fight or flight / rest and digest responses, for optimal health and performance.
Tracking your HRV can help
HRV is an extremely well researched area of study. But how does it work?
True HRV calculations require accurate measurement of the time in milliseconds between each heart beat. This is called an R-R interval.
But why is this important and what can it tell us?
Morning readiness is the most important reading. Take it for 2.5 minutes first thing in the morning, this will help you to identify your unique stress and recovery patterns. The key word here is "Patterns". Taken in isolation an individual reading gives limited information, use the first week of readings as a kind of baseline if you will.
I use a simple, inexpensive set up of Polar H7 Heart rate monitor, and EliteHRV app downloaded on to my phone.
What's the importance of Morning Readiness?
At any given time, many things can affect your heart rate variability. This includes physical and emotional experiences, internal processes like circadian rhythm and hormonal fluctuations.
By taking it first thing in the morning , you can eliminate many of the variables that impact your HRV.
Heart Rate Variability: The Science
HRV is very different from Heart Rate (HR) or Beats Per Minute (BPM) so don't get them confused!
Heart Rate Variability is the variation in time between successive heart beats over a period of time. The time between beats is sometimes called Inter-Beat Intervals (IBI's) or R-R intervals, and is measured in milliseconds.
HRV looks at the small fluctuations of the heart that happens because of changes both inside and outside our body. The readings of your HRV can tell us how ready we are to handle things like intense exercise, or other stressful situations. We can gauge when to push it, when to ease off and if we need to adjust our nutrition for better recovery. To understand this relationship better, lets take a look at your nervous system
Did you know that your body is a huge network of nerves, muscles, glands, vessels and so much more. The complex systems keeps you alive, fuels performance and controls your recovery, and the amazing thing about it? This all happens automatically and is controlled by your Automatic Nervous System (ANS).
Now your ANS has two different branches, which are
Sympathetic Nervous System (Fight or Flight)
This branch of the ANS increases blood pressure, increases heart rate, dilates pupils, and increases activity of the adrenal glands. These are all the things that are preparing you to Fight or Flight. There is no value judgement attached to this. You want your sympathetic side to be strong as well when you need to perform.
Parasympathetic Nervous System (Rest & Digest)
This plays a major role in digestion, sexual arousal, muscle repair, lowers blood pressure, lowers heart rate. Clearly you want to spend most of your time leaning towards the parasympathetic side, but as mentioned earlier you need to find the optimal balance for you specifically.
Now you may have noticed that the sympathetic nervous branch increases heart rate, while the parasympathetic branch decreases heart rate? These tiny changes in heart rate are the main cause of Heart Rate Variability , and these are the changes that we look to measure.
Finding Your Balance: What The Readings Mean
Here is a snap shot of my weekly reading as well as a single day, using the EliteHRV app
I could have given you a weekly snap shot where everything was perfect, but I wanted to give you an honest insight to how I use HRV to improve my performance and recovery. But first, lets look at what these colours mean.
As you can see in the picture, I hit a red on Saturday. This indicates a deeper level of recovery activity within my body, in response to accumulated stress. According to this reading my body was reaching an over trained state. On the Friday I did a weight training session that was at a high intensity (by that I mean high percentage of my 1RM) and was high volume, combine that with going out friday night and not getting to bed until around 2 am, and my nutrition not being on point, and there you have it, all up in the RED ZONE.
On red days, it's highly recommended to prioritise rest. So I tweaked my nutrition ensuring it was nutrient rich and anti-inflammatory. Plus I allowed myself to indulge in a power nap in the park (it was a gorgeous sunny day) and my active recovery was going for a walk.
Generally speaking, on a green day you can test your limits, and push yourself that little bit further. But make sure that you get adequate recovery in the form of sleep, and fine tune your nutrition, or chances are that you will end up in the yellow zone for a few days.
On yellow days its a good idea to reduce your exercise load, whether that be a reduction in intensity, volume or time. However the suggested tactic is to maintain intensity but decrease volume.
Now there are times where you or your Coach will want to push your training on a yellow day to achieve a specific adaptation in your training. If this is a case, it is usually followed by two days or so of reduced intensity and volume. It's doubly important to keep an eye on your HRV during this period. Only do this if you/ your coach know what you are doing. If you are unsure, it's best to just ease back on the training.
The ideal situation is to have a change in your HRV every few days, caused by acute stressors, followed by adequate recovery that allows improved performance.
While this is a very simplified overview, it serves to illustrate the importance of tracking your HRV.
If you are a busy highly stressed professional, who gets less than 7 hours sleep, probably has kids, and wants to workout 3 - 5 times a week, relentless HIIT training is probably not going to be the best option for you. It will most likely send you into the red, and have negative impact on everything from
I'm not saying HIIT training doesn't have its place (when used wisely), just that you need to take into account various other lifestyle factors and whether you are sympathetic or parasympathetic dominant. Tracking your HRV is a simple, non invasive way to do so.
Now this is also true for the endurance athletes who are busy professionals, functions on 6 hours sleep (at best) and a mediocre nutrition plan. Typically training for marathons, ultra marathons, or Iron Man competitions. They wonder why their times are erratic, improvements in performance drops, sex drive plummets and are plagued with frequent colds and illness.
Look it doesn't have to be this way.
Don't just track your performance. Improve it.
Research to whet your appetite
Measurement of HRV: Clinical Tool or Toy
Heart Rate Variability in athletes
Improvements in HRV with exercise therapy
Depression & HRV in Patients