Physical Activity Intensity Levels

Physical Activity Intensity

The Guidelines consider the intensity with which people do physical activity. Some activities are a higher intensity than others because they require more energy to do. For example, a person expends more energy walking briskly than slowly strolling. Absolute rates of energy expenditure during physical activity are commonly described as light, moderate, or vigorous intensity. Energy expenditure is expressed by multiples of the metabolic equivalent of task (MET), where 1 MET is the rate of energy expenditure while sitting at rest.

• Light-intensity activity is non-sedentary waking behavior (see sidebar) that requires less than 3.0 METs; examples include walking at a slow or leisurely pace (2 mph or less), cooking activities, or light household chores.

• Moderate-intensity activity requires 3.0 to less than 6.0 METs; examples include walking briskly (2.5 to 4 mph), playing doubles tennis, or raking the yard.

• Vigorous-intensity activity requires 6.0 or more METs; examples include jogging, running, carrying heavy groceries or other loads upstairs, shoveling snow, or participating in a strenuous fitness class. Many adults do no vigorous-intensity physical activity.

What Each Level Feels Like

Light exercise intensity

Light activity should feel easy. Here are clues that your exercise intensity is at a light level:

• Normal breathing
• You can move while talking to a friend or sibling

Moderate exercise intensity

Moderate activity feels somewhat hard. Here are clues that your exercise intensity is at a moderate level:

• Your breathing quickens, but you're not out of breath.
• You develop a light sweat after about 10 minutes of activity.
• You can carry on a conversation, but you can't sing.

Vigorous exercise intensity

Vigorous activity feels challenging. Here are clues that your exercise intensity is at a vigorous level:

• Your breathing is deep and rapid.
• You develop a sweat after only a few minutes of activity.
• You can't say more than a few words without pausing for breath.