When it comes to health and fitness tracking, one of my favorite health data points is Heart Rate Variability.
Appreciated as “HRV, “Many doctors and athletes consider heart rate variability to be one of the best biomarkers for understanding how your body, health, and fitness are affected by a whole host of factors like training load, sickness, alcohol, nutrition, sleep, and air quality to name a few. Psychologists have even used HRV through activities like meditation and guided breathing to treat psychological issues. While it’s mostly been used by elite and Olympic athletes to gauge their training stimulus, load and recovery, it’s increasingly become a useful data point for the recreational athlete too.
In short, Heart Rate Variability (HRV) is a great biomarker to understand your life.
What can HRV data be used for? HRV can be used to help you look at how certain lifestyle changes affect you. For example, by measuring HRV, you can see correlations in how a previous day of hard training, a night of poor sleep or excessive drinking among a few notable factors affects your HRV value the next day. Over longer periods you can use HRV readings to see other chronic trends in your health, wellness and fitness.
For self-tracker and quantified self enthusiasts, HRV data provides a reference point for understanding aspects of your life and your self-experiments. The challenge is that you can’t run a controlled experiment when your sample size is only you. Fortunately, with HRV it becomes possible to measure the effect of life changes in terms of your HRV. For example, HRV data can be a good data point to measure the effect of different training or nutrition regimes.
One of the other great features of Heart Rate Variability is that it is a particularly easy biomarker to measure. Using either your phone or a chest strap heart rate monitor, there are several services that can enable you to log your reading to your smart phone and then help you track changes over time. In about a minute, you can log your HRV biomarker. There are also several running watches and wearables that provide an estimation of your HRV too.
As a slightly obsessive self-tracker, I measure many aspects of my life, including my productivity time, my workouts, my tasks, my weight and many others. Personally, I measure my HRV each morning and have seen connections and correlations between several aspects of life and my HRV scores. For example, during my recent marathon training and 42k run, I saw noticeable changes in my HRV readings, and, as a regular traveler, it is easy to spot how long and short travel affects us physiologically.
So, what is HRV? What are you measuring with HRV? What does this particular measurement signal when it comes to your health and fitness? What are a some things that affect your HRV and how can you see this in your data? And finally why should HRV matter in general and for you personally?
In this long post, we are going to explain what is HRV and how it is measured (both practically as a user and scientifically as a biomarker). We will look at why it is important to log the context with your HRV and some of the factors that can affect your HRV day to day and chronically over time.
This post is intended as a beginner’s intro to HRV, so we’ve left out the deeper science behind HRV, including the automatic nervous system. I plan to provide more on this and demographic HRV comparisons in a later post.
Obviously the body and its interaction are complicated. Yet HRV remains an incredibly interesting data point to better understanding yourself. Let’s dig in!