Aerobic exercise (also known as
cardio) is
physical exercise of low to high
intensity that depends primarily on the aerobic
energy-generating process. Aerobic literally means "relating to, involving, or requiring free oxygen", and refers to the use of
oxygen to adequately meet energy demands during exercise via aerobic metabolism. Generally, light-to-moderate intensity activities that are sufficiently supported by aerobic
metabolism can be performed for extended periods of time.