Heart rate variability – what to know about this biometric most fitness trackers measure
- Written by Anne R. Crecelius, Associate Professor of Health and Sport Science, University of Dayton
An increase in this particular biometric is a good thing.visualspace/E+ via Getty ImagesYour heart beats around 100,000 times every day. Heart rate is a key marker of cardiovascular activity and an important vital sign. But your pulse is not as steady as a precision clock – nor would you want it to be.





