VO2max is a measure of cardiovascular fitness, and many watches and fitness trackers can estimate it for you. Here's what you need to know.
The more you work out, the fitter you'll get. Your VO2max, sometimes described on wearables as a "cardio fitness" score, is a number that tends to be higher among people who are more cardiovascularly fit. But it's not the only measure of fitness, and... [5136 chars]