What does the metabolic equivalent (MET) measure in physical activities?

The metabolic equivalent (MET) is a unit that measures the energy cost of physical activities relative to an individual’s resting metabolic rate. One MET is defined as the energy expenditure at rest, which is approximately equivalent to consuming 3.5 mL of oxygen per kilogram of body weight per minute. When physical activities are expressed in METs, it allows for a standardized way to compare the intensity of various activities based on the relative increase in energy expenditure from the resting state.

For instance, a task that requires 5 METs indicates that a person is expending five times more energy than when at rest. This metric is particularly useful in exercise prescription, physical fitness assessments, and understanding the energy demands of different activities. By relating activities back to resting energy expenditure, practitioners can better design and tailor programs for individuals based on their fitness level and specific health-related goals.

The other options describe different aspects of exercise physiology but do not accurately capture the essence of what a MET signifies in terms of energy expenditure. For example, heart rate measures cardiovascular response, maximum oxygen uptake (VO2 max) assesses aerobic capacity, and calorie burn per minute calculates energy expenditure without the context of resting metabolic rates, which is central to the definition of METs.