Here’s a non—paywall story that discusses HRV: http://www.telegraph.co.uk/men/thinking-man/heart-rate-variability-testing-can-use-get-healthier/ http://www.tel

Here’s a non—paywall story that discusses HRV: http://www.telegraph.co.uk/men/thinking-man/heart-rate-variability-testing-can-use-get-healthier/ http://www.telegraph.co.uk/men/thinking-man/heart-rate-varia... “heart rate variability is essentially the gap between heartbeats when you are resting. A longer gap between heartbeats indicates you are well rested, whereas a shorter gap could mean you are stressed out and running the risk of overtraining”