MET (Metabolic Equivalent of Task) cost refers to the energy expended during a physical activity, often expressed in terms of calories burned. Calculating MET cost helps in understanding the intensity of an exercise and its impact on your overall energy expenditure.
Understanding METs
A Metabolic Equivalent of Task (MET) is a unit used to estimate the amount of oxygen the body uses during physical activity, serving as a standardized measure of its energy cost. One MET is defined as the energy expended when sitting quietly at rest. For the average adult, this is approximately equivalent to burning about 1 calorie per kilogram of body weight per hour (1 kcal/kg/hour). Similarly, it's roughly 1 calorie burned for every 2.2 pounds of body weight per hour.
When an activity has a MET value higher than 1, it means you are expending energy at a rate that is X times your resting metabolic rate. For instance, an activity with a MET value of 3 means you are expending three times the energy compared to being at rest.
The Formula for Calculating Calorie Cost
To calculate the calories burned using METs, you can use the following straightforward formula:
- Calories Burned (kcal/hour) = METs x Body Weight (kg) x 1
Alternatively, if you prefer to use pounds for body weight:
- Calories Burned (kcal/hour) = METs x Body Weight (pounds) / 2.2
If you need to calculate calories burned per minute, divide the hourly result by 60:
- Calories Burned (kcal/minute) = [METs x Body Weight (kg)] / 60
Variables Explained:
- METs: The metabolic equivalent value for the specific activity. This value is usually standardized and can be found in various exercise science resources.
- Body Weight (kg): Your body weight in kilograms. (To convert pounds to kilograms, divide your weight in pounds by 2.2.)
- 1 or 1/2.2: Represents the approximate resting energy expenditure of 1 kcal per kg per hour, or 1 kcal per 2.2 pounds per hour.
Practical Steps to Calculate MET Cost
- Find the Activity's MET Value: Determine the MET value for the specific activity you want to calculate. These values are widely available in charts and databases (e.g., the Compendium of Physical Activities).
- Determine Your Body Weight: Weigh yourself and convert your weight to kilograms if necessary.
- Apply the Calculation: Plug the MET value and your body weight into the formula to find the estimated calories burned per hour or per minute.
Example Calculation
Let's calculate the MET cost (calories burned) for a person weighing 70 kg (about 154 lbs) cycling at a moderate pace for 1 hour.
- Activity: Cycling, moderate pace
- Approximate MET value: 8.0 METs
- Body Weight: 70 kg
Using the formula:
Calories Burned (kcal/hour) = METs x Body Weight (kg) x 1
Calories Burned (kcal/hour) = 8.0 x 70 kg x 1
Calories Burned (kcal/hour) = 560 kcal/hour
So, a 70 kg person cycling at a moderate pace for one hour would burn approximately 560 calories.
Common Activity MET Values
Here's a brief table of approximate MET values for various activities to give you an idea:
| Activity | Approximate METs |
|---|---|
| Sleeping | 0.9 |
| Sitting Quietly | 1.0 |
| Walking (leisurely, 2 mph) | 2.5 |
| Yoga | 2.8 |
| Walking (brisk, 3.5 mph) | 4.3 |
| Cycling (moderate, 10-12 mph) | 8.0 |
| Running (6 mph / 10 min/mile) | 10.0 |
(Note: MET values are averages and can vary based on individual effort, terrain, and specific activity nuances.)
Importance of METs
Understanding MET cost is valuable for:
- Fitness Tracking: Helps individuals monitor their calorie expenditure during workouts.
- Exercise Prescription: Allows trainers and healthcare professionals to recommend appropriate activity levels for health goals.
- Weight Management: Aids in balancing calorie intake with energy expenditure for weight loss or maintenance.
- Research: Provides a standardized unit for comparing the intensity of different physical activities across studies.
