Exercise intensity refers to how much energy is expended when
exercising. Perceived intensity varies with each person. It has been found that intensity has an effect on what
fuel the body uses and what kind of adaptations the body makes after exercise. Intensity is the amount of physical power (expressed as a percentage of the
maximal oxygen consumption) that the body uses when performing an activity. For example, exercise intensity defines how hard the body has to work to walk a mile in 20 minutes.