What is VO2 max?

• A. Maximum amount of oxygen that can be transported and used by the body in a specified period of intense/maximal exercise
• B. A measure of cardiovascular fitness
• C. Time between presentation of stimulus and onset of movement
• D. Percentage of body weight that is fat, muscle, and bone

Answer: (A)

VO2 max is the maximum rate at which your body can take in, transport, and use oxygen during intense exercise. It shows how well the cardiovascular system (heart, blood vessels, lungs) can deliver oxygen and how effectively your muscles can use that oxygen for energy. It's usually measured in ml of O2 per minute per kilogram of body weight (ml/kg/min) and is a key indicator of aerobic fitness because a higher value means you can sustain higher intensities for longer.

The other descriptions refer to related ideas but not the specific definition: one is a general measure of cardiovascular fitness, another is reaction time, and another is body fat and muscle composition.