My Experience Measuring HRV

Fix Your Metabolism, Fix Your Life.

My Experience Measuring HRV

If you haven’t heard of HRV, it stands for “Heart Rate Variability.”  Mostly likely, you are familiar with measuring Heart Rate, which measures the number of heart beats per minute.  HRV measures the time between the beats.  It’s a little counterintuitive that a steady and consistent HRV measurement is a sign of too much stress (Sympathetic Nervous System activation), whereas a highly variable or random HRV measurement is a sign of a healthy amount of stress (a balance between the Sympathetic and Parasympathetic systems).  Elite coaches and trainers are using HRV to measure “readiness to train”, so I decided to give it a try and see what I might find.

I started by installing the EliteHRV smartphone app.  There are a number of different HRV measurement apps, and I did take some time to investigate which one I wanted to use.  I ended up going with EliteHRV after listening to their podcast and deciding that they knew what they were doing.  The near universally agreed gold standard for measuring readiness to train is the Omega Wave, but it is over $200 and requires a monthly subscription, so I decided to go with the free EliteHRV app and a $60 chest strap.

I have only been measuring HRV for a couple months, but I believe that its long enough to draw some interesting conclusions.  My biggest conclusion is that non-training stress affects HRV far more than grueling exercise.  The biggest example of this is sleep.  I discovered this because my family ended up watching the Oscars on DVR several hours delayed and we ended around 2am.  I very rarely stay up that late, and probably had not stayed up that late in over a year.  The next day, my HRV measurement was the lowest I have ever recorded.

This was a huge insight.  I was already a big advocate of good quality sleep, and I knew that sleep was of paramount importance.  But I had no idea that ONE NIGHT of going to bed late would have such an immediate and noticeable impact.  This really made me re-think my approach to training after a poor night’s sleep, or going to bed late, or getting up early.  It made me realize that training hard after poor sleep is really adding insult to injury, and that one night of bad sleep really matters.

By contrast, it takes more than just one day of really difficult training in order to have an impact on HRV.  For example, I had the following three days of training really hard, and my HRV wasn’t reporting that I wasn’t ready to train until after the 3rd day:
Monday:  11 mile aerobic run
Tuesday:  3 mile aerobic run, morning heavy lifting session, evening heavy lifting session (57 sets total between both)
Wednesday:  morning 6 mile aerobic run, evening 6 mile aerobic run

After this three day stretch, my HRV measurement finally said that I was not ready to train and needed to rest, but even this measurement was not as low as one night of going to bed late!!  Here are screenshots of the two readings for comparison:

        Going To Bed Late:                           Three Days of Hard Training:
                 

I am continuing to use and learn more about HRV.  I am excited to see what other insights I can glean from my daily habits and routines.  Another thing I’ve learned that will affect my training going forward is how little aerobic training affects HRV.  I have so far been unable to produce a “not ready to train” result just with aerobic volume.  I haven’t put in really high volume yet, so I am a little anxious to see how much volume it takes to affect HRV.  Another thing I want to check out is how much anaerobic training it takes to affect HRV.  My guess is that it won’t take much, but I also expect that I might be able to handle more anaerobic training that I am currently doing and still not be overtrained.  Hope this post was helpful.  If you have any insights to share with HRV, please contact me.