Heart Rate Variability or HRV has emerged as one of the most useful applications for assessing and tracking your body’s general health, performance, and recovery status.

While its ease of access is relatively new, researchers and physiologists have been tracking and utilizing HRV for decades. In general, high heart rate variability indicates strong cardiovascular fitness and good overall health. As a practical application, it tells us how well-recovered and ready to train we are on any given day. Because HRV can react to changes in our body even faster than our heart rate can adapt, it is a particularly sensitive tool that gives us insights into the immediate status of our wellbeing.

Although it may sound counterintuitive, a healthy heart beat should contain some slight irregularities. It should not function like clockwork; the length of time between heartbeats should var. With no input from the autonomic nervous system, a healthy heart contracts at an intrinsic (or built-in) rate of about 100 beats per minute. Parasympathetic regulation lowers the heart rate from its intrinsic level, giving more room for variability between beats. Sympathetic regulation does just the opposite; it elevates the heart rate leaving less room for variability.

When evaluated in tandem, these two possibilities allow for the formulation of a basic rule—when the rest-related parasympathetic branch is active and the sympathetic branch is inactive, your heart rate will be lower and your HRV higher. Mental and physical stress will reduce parasympathetic activity and increase sympathetic activity. Athletes struggling with health and performance issues should strive to activate their parasympathetic nervous system as much as possible.

There are no standard guidelines for optimal HRV values because it’s affected by myriad internal and external variables including your age and gender. Women typically have a higher heart rate variability than men.

There are a variety of HRV applications currently available. I highly recommend the free Elite HRV app paired with the Polar H10 heart rate strap.

Have you heard or read anything about heart rate variability before? Is this type of daily, tracking technology something you would find useful? Please share any comments or questions below.