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You’re probably aware that your body burns energy all the time, no matter what you’re doing.

But have you ever wondered how much energy you’re burning throughout the day, or when you’re indulging in big-time calorie burners, like running or lifting weights?

One way to calculate your body’s energy expenditure is with metabolic equivalents, also known as METs. You might see METs listed on exercise equipment or mentioned by personal trainers to help you measure your physical activity.

In this article, we’ll take a closer look at how METs work, how to calculate them, and how to use them to help you reach your fitness goals.

A MET is a ratio of your working metabolic rate relative to your resting metabolic rate. Metabolic rate is the rate of energy expended per unit of time. It’s one way to describe the intensity of an exercise or activity.

One MET is the energy you spend sitting at rest — your resting or basal metabolic rate. So, an activity with a MET value of 4 means you’re exerting four times the energy than you would if you were sitting still.

To put it in perspective, a brisk walk at 3 or 4 miles per hour has a value of 4 METs. Jumping rope, which is a more vigorous activity, has a MET value of 12.3.

Summary
  • METs = metabolic equivalents.
  • One MET is defined as the energy you use when you’re resting or sitting still.
  • An activity that has a value of 4 METs means you’re exerting four times the energy than you would if you were sitting still.

To better understand METs, it’s helpful to know a little about how your body uses energy.

The cells in your muscles use oxygen to help create the energy needed to move your muscles. One MET is approximately 3.5 milliliters of oxygen consumed per kilogram (kg) of body weight per minute.

So, for example, if you weigh 160 pounds (72.5 kg), you consume about 254 milliliters of oxygen per minute while you’re at rest (72.5 kg x 3.5 mL).

Energy expenditure may differ from person to person based on several factors, including your age and fitness level. For example, a young athlete who exercises daily won’t need to expend the same amount of energy during a brisk walk as an older, sedentary person.

For most healthy adults, MET values can be helpful in planning an exercise regimen, or at least gauging how much you’re getting out of your workout routine.

Summary

One MET is approximately 3.5 milliliters of oxygen consumed per kilogram of body weight per minute.

Researchers who have monitored oxygen consumption in the muscles of people performing various activities have been able to assign MET values to those activities. These values are based on a person weighing 70 kg, or 154 lbs.

This chart provides approximate MET values for a variety of light, moderate, and vigorous activities.

Light
< 3.0 METs
Moderate
3.0–6.0 METs
Vigorous
> 6.0 METs
Sitting at a desk: 1.3Housework (cleaning, sweeping): 3.5 Walking at very brisk pace (4.5 mph): 6.3
Sitting, playing cards: 1.5 Weight training (lighter weights): 3.5Bicycling 12–14 mph (flat terrain): 8

Standing at a desk: 1.8
Golf (walking, pulling clubs): 4.3Circuit training (minimal rest): 8
Strolling at a slow pace: 2.0 Brisk walking (3.5–4 mph): 5Singles tennis: 8
Washing dishes: 2.2 Weight training (heavier weights): 5Shoveling, digging ditches: 8.5
Hatha yoga: 2.5Yard work (mowing, moderate effort): 5 Competitive soccer: 10
Fishing (sitting): 2.5Swimming laps (leisurely pace): 6Running (7 mph): 11.5

The American Heart Association recommends at least 150 minutes of moderate-intensity aerobic exercise each week for optimal cardiovascular health. That’s equal to about 500 MET minutes per week, according to the Department of Health and Human Services.

How you reach those goals — whether it’s through running, hiking, weight training, or any other activity — is less important than simply striving for those targets.

You may be more familiar with calories than METs, especially if you pay attention to the calories you consume and burn each day.

What you also likely know is that the more oxygen your muscles use, the more calories you burn. What you may not know is that you have to burn about 3,500 calories to lose 1 pound of body weight.

That means if you reduce your daily calorie intake by 500 calories or burn 500 more calories each day than you consume, you may be able to lose a pound a week.

So, if you know the MET value of a particular activity, can you figure out how many calories you’re burning? Well, you can probably come up with a close estimate.

The formula to use is: METs x 3.5 x (your body weight in kilograms) / 200 = calories burned per minute.

For example, say you weigh 160 pounds (approximately 73 kg) and you play singles tennis, which has a MET value of 8.

The formula would work as follows: 8 x 3.5 x 73 / 200 = 10.2 calories per minute. If you play tennis for an hour, you’ll burn about 613 calories.

You could also describe that tennis workout as equal to 480 MET minutes (8 METs x 60).

A MET is a way to measure your body’s expenditure of energy. The higher the MET value of a particular activity, the more energy your muscles will need to expend to do that activity.

Knowing the MET value of an activity can also be helpful in calculating how many calories you burn during exercise.

Aiming for at least 500 MET minutes a week is a good goal for optimal cardiovascular health. How you reach that goal is up to you.

You can perform moderate exercise, like brisk walking, over a longer period of time. Or you can do more vigorous activity, like running, for a shorter period of time.