Your watch’s VO2 max isn’t perfect, but you can improve its accuracy with better data and heart-rate tracking.

VO2 max, the measure of how much oxygen the body consumes during exercise, has become a ubiquitous tool for professional ...

VO2 max is an intimidating word for an easy-to-understand biometric: It’s how well your body uses oxygen when you push yourself. Short for “maximal oxygen uptake,” it’s been the gold standard for ...