VO2 max testing requires a mask to measure oxygen intake and carbon dioxide output to determine your cardiovascular fitness.

Ever wish you could breathe easier and sustain more intensity mid-workout? You may have overheard the term "VO2 max" at the gym or on a trainer’s social media page recently—but what is this ...

Women's Health may earn commission from the links on this page, but we only feature products we believe in. Why Trust Us? Ever wish you could breathe easier and sustain more intensity mid-workout?