This video segment adapted from NOVA describes the effect of exercise on the body and defines one measure used to gauge aerobic fitness. VO₂ max (maximal volume of oxygen uptake) is a measurement of how well the body gets and consumes the oxygen that muscles need in order to sustain activity. Learn how the entire cardiovascular system benefits from exercise and how the body's response to the demands of physical activity is a survival mechanism.

This video is available in both English and Spanish audio, along with corresponding closed captions.