envision a reservoir residing in your body that stores the precious fight-or-flight hormone cortisol.

Unfortunately, you are headed for a burnout when your sympathetic nervous system and fight-or-flight hormones become exhausted from chronic stimulation.

A high HRV value suggests a healthy, fit, stress-balanced subject. A sustained pattern of low HRV readings suggests a state of overstress or exhaustion.

Beyond Training - Ben Greenfield

WHY HRV IS BETTER THAN RESTING HEART RATE TO MONITOR STRESS AND RECOVERY

The more variation in beat-to-beat intervals, the higher your HRV score and generally the more fit and healthy your cardiovascular system.

Genes have no effect until they are expressed is worth reflecting upon for a moment.

“The brain recognizes what’s familiar and filters out other things so you can remain focused on the task at hand. If you’re in a chronic fight-or-flight state, your brain recognizes this familiar operating mode (amped, emotional, reactive, harried, etc.) and you feel comfortable.

All you need is a Bluetooth low energy (BLE 4.0)-enabled wireless chest transmitter and a smartphone app, such as the PrimalBeat HRV Tracker App for iPhone.