If you're trying to lose weight, you might be surprised to learn that your current weight could give you a slight advantage. When all other factors are equal, heavier people burn more calories doing the same exercise routine. However, several variables affect the number of calories you'll burn doing any single exercise, so you can't count solely on your weight to help you burn them more quickly.
Why Weight Affects Calories Burned
A calorie is simply a unit of energy, so the number of calories you burn during exercise is actually a measure of the energy required to move your body. Larger people require more energy to move their bodies, so you'll typically burn more calories at a heavier weight. For example, Harvard Medical School reports that 30 minutes of weightlifting burns about 90 calories in a 125-pound person, 112 calories in a 155-pound person and 133 calories in a 185-pound person.
Fat Versus Muscle
Although weight affects the number of calories you burn, muscle mass can play an equally important role. Muscle burns more calories than fat. Consequently, two people of the same weight can burn different numbers of calories if one person has a high muscle mass and the other has a low muscle mass. You can't rely on your weight alone as a predictor of the calories you'll burn because your weight doesn't provide information about body composition.
Exercise intensity is a major factor determining how many calories you burn. A lighter person might burn more calories running than a heavier person, for example, if she runs uphill or at a faster speed. Overall physical fitness also may affect the calories you burn because as you get into better shape, your body learns to work more efficiently.
Weight as a Liability
Although your weight can help you burn more calories, it also can be a hindrance, particularly if you are significantly overweight. You might not be able to move as quickly, exercise as long or do challenging, intense routines. As you lose weight, you might notice that you begin exercising longer and more efficiently, potentially helping you burn more calories.
- Harvard Health Publications: Calories Burned in 30 Minutes for People of Three Different Weights
- University of New Mexico, Len Kravitz: Making Sense of Calorie-Burning Claims
- Runner's World: How Height Affects Calorie Burning
- MayoClinic.com: It's Complicated - Calories and Other Factors Affect Weight Loss
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