1. Understanding Metabolic Equivalents (METs)
A **Metabolic Equivalent of Task (MET)** is a standardized physiological index used to estimate the energy cost of physical activities. One MET is defined as your energy expenditure at rest (approximately **3.5 ml of oxygen per kilogram of body weight per minute**).
Physical activities are assigned MET values based on their intensity relative to rest. For example, an activity with a MET value of 4 requires four times the energy of resting. MET values are established through clinical testing to help standardized energy expenditure calculations.
2. The Calorie Expenditure Formula
The standard formula to calculate calories burned using MET values is: Calories Burned = Activity Duration (minutes) × (MET × 3.5 × Weight (kg) / 200).
This formula estimates energy expenditure by incorporating the relative intensity of the activity (MET), your body mass, and the duration of the physical exercise.
3. Role of Exercise in Weight Management
To lose weight, you need to create a calorie deficit. While reducing dietary calorie intake is often the primary driver of a deficit, increasing physical activity can support this goal by increasing your overall energy expenditure.
Combining a moderate calorie deficit with regular exercise can support sustainable weight loss while helping to maintain cardiovascular fitness and lean muscle mass. You can estimate your safe deficit target using our Weight Loss Calculator.
4. Variables That Affect Calories Burned
Your actual energy expenditure during exercise is influenced by several individual factors:
- Body Mass: Larger bodies require more energy to move, resulting in a higher calorie burn for the same physical activity.
- Exercise Intensity: Working at a higher intensity (e.g. running faster or lifting heavier) increases your oxygen demand, which in turn increases the MET value and overall calorie burn.
- Body Composition: Muscle tissue is more metabolically active than fat tissue. Individuals with a higher percentage of lean muscle mass may burn slightly more calories during physical activity. You can estimate your body fat using our Body Fat Calculator.