EXERCISE CALORIE CALCULATOR:
Your body burns calories to generate energy. The calories it doesn't burn are stored as fat. A healthy diet will improve your health, but if you consume more calories than your body can burn the excess will be stored as fat. Muscle burns around 3 times more calories than fat even when you're resting, which is why your body composition is important to your ability to burn calories efficiently. Your body loses lean muscle mass as it ages. That's why it's more difficult to exercise when you're older. Your Basal Metabolic Rate determines how many calories your body burns and how many it stores as fat. After age 21 your BMR declines about 2 % per year as you age. If you don't do anything to retain lean muscle mass as you age, you will have to reduce the number of calories you consume each year just to maintain your current weight. Fat does not burn calories, muscle does. You don't build muscle by eating, you build muscle through exercise!
Use this exercise calorie calculator to measure how many calories you burn through exercise. If you need help calculating your BMR go here: http://www.worldlifeexpectancy.com/bmr-calculators