Our metabolisms are responsible for calories burned. According to the Mayo Clinic, “Metabolism is the process by which your body converts what you eat and drink into energy.” You need energy for your body’s basic functions, such as circulating blood, adjusting hormone levels, breathing and growing and repairing cells. This includes maintaining muscle mass. Your body requires 60 to 75 percent of calories consumed to complete these tasks. Food processing accounts for about 10 percent of daily calories consumed, and physical activity accounts for the rest.

Use a calorie counter or chart found online to determine how many calories you burn per hour during a particular activity. Keep in mind, though, that these calculators and charts are not exact because factors such as your sex, age and size affect the number. A typical man will burn more calories than a typical woman of the same age, younger people will burn more calories than older people and heavier people more than thinner. Also, the more strenuously you perform the particular activity you’re looking at on the chart, the more calories you will actually burn. In other words, when possible, use calculators that ask you to put in your weight, sex and age for most accurate numbers.

Monitor your exertion levels by asking yourself how hard your workout feels. Calorie calculators and charts will tell you that a 154-lb. individual burns 279 calories per hour of water aerobics and 440 in an hour of basketball. However, if this individual plays basketball at a leisurely pace but pushes himself hard during the water aerobics, 279 could instead apply to the basketball and 440 to the aerobics. Your exertion should stay at “somewhat hard” level for these numbers to be the most accurate.

Determine your weight and body fat levels. These charts and calculators are based on the average person doing the particular activity at a medium intensity. If you are heavy and more muscular than the average person in your age bracket, you will burn more calories doing a given activity than the calculator indicates. Conversely, if you are lighter than average but have lots of body fat, you will burn fewer calories. Remember, it IS possible to be fat even though you’re skinny:) Try this to determine if you are a “skinny fat” person: Pinch the skin in the middle of your thigh with your thumb and index finger and the skin beside your navel. (Women should pinch diagonally at their hip, not by the navel.) The thicker the pinched skin fold, the higher your body fat. In other words, if it’s about an inch thick, you probably need to lower your body fat levels.