Heart rate variability, or HRV for short, has been gaining more and more mainstream attention lately.
As science has done more work in this area, commerce has caught up with more and more wearable devices able to provide accurate HRV readings.
Regular weekend warriors are now able to track what is one of the most insightful biometrics we have, all at an affordable price.
But before you go looking for your next piece of wearable tech, let's understand what heart rate variability is and why it matters at all.
What Is Heart Rate Variability?
The human heart does not beat at a consistent cadence at all times. There is variation between the beats based on a number of physiological inputs.
This variation between beats is heart rate variability (HRV).
When measuring HRV, we are measuring the variation in miliseconds over a given time frame. Devices will differ on the time frame they use.
- When the intervals between heart beats is fairly consistent, your HRV is low. This is an indicator of not being well recovered or possible sick or injured.
- When the intervals between heart beats is more irregular, your HRV is high. This means you are recovered and rested and ready to train.
We can further understand the physiological impact of these variations by attaching them to the nervous system.
Heart Rate Variability And Your Nervous System
Heart rate variability tells us a lot about what's going on in with our nervous system. To summarize simply:
- Higher HRV and lower heart rate indicates the dominance of the parasympathetic nervous system
- Lower HRV and higher heart rate indicates the dominance of the sympathetic nervous system
The parasympathetic nervous system is a state of calm, rest, and recovery. When the sympathetic nervous system takes over, you are entering the fight or flight mode.
Fight or flight is evolutionarily important and there are times where we want to be there, but sustained periods with the nervous system redlined like this without recovery can lead to injury.
How To Measure Heart Rate Variability
Measuring heart rate variability will require and external tool. There are many out there on the market, but I have experience with two of them: the Oura Ring and Whoop Strap.
I won't go into specifics here, because both have their pros and cons.
What I will say is I chose to keep the Whoop Strap for my long term solution.
What You Can Learn From Tracking Your Heart Rate Variability
Put simply, heart rate variability is an important marker of physiological stress. The lower your variability, the less recovered you are.
By measuring HRV over time, you can determine if your recovery methods are effective, if you are sleeping enough, what types of workouts produce the most stress, when to back off, and much more.
If you are looking to improve your performance or are training for any type of athletic event, even if only as an enthusiast, tracking your heart rate variability, and REACTING to changes in it, is a powerful training tool.