Heart Rate Variability
Heart Rate Variability (HRV in short) is literally the the variance between each heart beat. So if your heart is beating 60 beats per minute, it’s not actually beating once every second. Within that minute there could be a time of 0.85s between two beats and 1.15s between another two. The greater the variance is, the better you will be at performing that day.
Even though HRV is measured via your heart beat, what we actually can measure is your nervous system.
Your Autonomic Nervous System (ANS), controls all involuntary aspects of your physiology. It has two branches, parasympathetic (deactivating) and sympathetic (activating).
The parasympathetic branch (PNS) is often referred to as “rest and digest”. This branch handles inputs from internal organs, like digestion. It also causes a decrease in heart rate.
The sympathetic branch (SNS) is often called “fight or flight”. This branch activates responses to things like stress and exercise. It is also responsible to increase your heart rate.
HRV is determined from the signals both the ANS and PNS are sending to your heart. So if your nervous system is balanced, it will be sending out signals from both branches, which causes a fluctuation in your heart rate.
When you have high HRV, it means that your body is responsive to both the ANS and SNS branches. This is a sign that your nervous system is balanced, and that your body is very capable of adapting to its environment and performing at its best.
If we flip that to you having a low HRV, one branch is dominating (which usually is the sympathetic “fight or flight”) and sending stronger signals to your heart than the other. There are times when this is a good thing; like if you’re squatting something heavy you want your body to be allocating resources to your legs (sympathetic) as opposed to digesting food (parasympathetic).In a future article you’ll be able to read more on HRV and