How can you estimate your VO₂ max?

You can have your maximum capacity tested at performance labs, physical therapy facilities, and medical centers, but because it’s so uncomfortable (think: a dizzying all-out effort on a treadmill that leaves many close to puking), costly ($150 to $250), and not advised for all (all-out efforts are considered dangerous for some populations), many opt for a sub-max test or a formula like the one here instead.

Calculate yours with your age, resting heart rate, and maximum heart rate:

VO₂ max = 15.3 x (MHR/RHR)

You could also try a watch that includes a VO₂ max estimation feature. The more you wear the watch, the more accurate your number will be. Generally, wearables tend to underestimate because we very rarely hit the top end of our capacity while working out. That said, they all use your heart rate during certain workouts while also taking into account other factors, such as distance or altitude, to provide a fuller picture of your VO₂ max.