Heart Rate Variability (HRV) is the beat to beat variation in our heart rate. This is an indirect measure of our autonomic nervous system (ANS).
The autonimoic nervous system (ANS) is the system in our bodies that controls everything that happens automatically. Think of things such as; heart rate, blood pressure, breathing, posture, hormones, digestion and so much more.
The ANS has two sides; the sympathetic side, we will call it the gas pedal. And the parasympathetic side, we will call this the brake pedal. We want a perfect balance of the two sides so the body can react to a stressor when necessary (gas pedal) and go back to a growth & repair state after (brake pedal).
HRV gives us a measure of how balanced the ANS is or isn’t. To way oversimplify it; a high HRV means good balance and your ANS is working well. A low HRV may indicate an imbalance between the brake and gas pedals and or a poor functioning ANS overall. There is much more to consider, but that is a basic idea for now.