Physical activity of all kinds can be performed in a variety of intensities, ranging between light, moderate, and vigorous (high) intensity activity. Understanding the difference between intensity levels is important to understanding the current Physical Activity Guidelines for Americans.
Light intensity activities require the least amount of effort, compared to moderate and vigorous activities. The definition for light intensity activity is an activity that is classified as < 3 METS. One MET, or metabolic equivalent, is the amount of oxygen consumed while sitting at rest. Thus, an activity classified as 2 METS would be equal to 2 times the amount of oxygen consumed while sitting at rest (1 MET). METS are a convenient and standard method for describing absolute intensity of physical activities. Some examples of light physical activities include: walking slowly (i.e. shopping, walking around the office), sitting at your computer, making the bed, eating, preparing food, and washing dishes.
Moderate intensity activities are defined as activities ranging between 3 - < 6 METS. These activities require more oxygen consumption that light activities. Some examples of moderate physical activities include: sweeping the floor, walking briskly, slow dancing, vacuuming, washing windows, shooting a basketball.
Vigorous intensity activities are defined as activities ≥ 6 METS. Vigorous activities require the highest amount of oxygen consumption to complete the activity. Examples of vigorous physical activities include: running (5 mph >), swimming, shoveling, soccer, jumping rope, carrying heavy loads (i.e. bricks).
An easy way to estimate intensity of activities is through a method called the “talk test”. This method is a simple, practical way for individuals to measure their activity intensity. If you are doing a moderate intensity activity, you can talk, but not sing during the activity. If you are doing a vigorous intensity activity, you will not be able to say more than a few words without taking a breath.
For intensity levels of common daily activities visit the Compendium of Physical Activities.