When you hear the word metabolism, it is best to think of the number of calories burned by your body. A calorie is a unit of measure of energy for our body. The foods we eat supply the calories through protein, carbohydrate, and fat. How many calories we burn differs from one person to the next. The information here will help you understand your metabolism, how it relates to the calorie equation, and how you can boost it for optimum weight management.
How is a Calorie Burned?

We use calories for every function our body endures. Breathing, blood flow, heart beat, and kidney function all require energy; hence calories are being used as these involuntary mechanisms are taking place. Every organ system in our body is made up of millions of cells and each cell created energy in an effort to function properly. This, then, is how calories are burned.

Exercise Calories

Another way in which our body uses energy is through voluntary exercise. For example, it takes a certain number of calories to walk one mile. Every activity requires a different amount of calories. This is why highly trained athletes such as triathletes or cyclists, need to consume enormous amounts of food. The sedentary person requires much fewer calories since the only calories being burned on a regular basis is what the involuntary organ activities require.

Basal Metabolic Rate

Your basal metabolic rate (BMR) is the number of calories that you body needs to run on a daily basis without any extra physical activity or exercise routines. It is this number that is key to weight management, whether it be weight loss, weight gain, or weight maintenance. For example, if a person's BMR determines a caloric requirement of 1400 calories per day, then theoretically this is the amount of food that person would eat to maintain his or her current weight. If weight gain was intended, then an increase of 250 - 500 calories each day would result in a ½ to 1 pounds weight gain over the course of seven days. For weight loss, a deficit of that amount of calories would result in a weight loss of ½ to 1 pound over the course of week's time.

How to Determine Number of Calories Burned

Physical activity is often recommended for weight management purposes because it causes the caloric deficit the body needs in order to lose weight. When incorporated into a healthy diet, exercise can significantly encourage weight loss. Here is a short list of some activities and the number of calories burned based on a 120 pound person per hour of activity. The number of calories increases as body weight increases.

aerobic dance 330
bicycling at 10mph 220
bowling 165
driving a car 110
eating 80
gardening 275
golfing (walking) 250
hiking 330
horseback riding 220
housework 135
jogging 385
sleeping 50
soccer 385
swimming 330
tennis 385
walking (brisk) 220
watching TV 55
weight training 165
As you can see, the more vigorous the activity, the more calories burned. This is why it is best to get up and move instead of being sedentary most of the time.

Metabolic Differences

Every person is made differently and so are their metabolisms. While age, weight, height, gender, and genetics are pieces to the metabolic puzzle, body composition is a large piece as well. A person with a lean muscle mass greater than fat mass will have a higher BMR than a person with a higher fat to muscle mass ratio. This is because muscle tissue is highly metabolic and burns more calories per hour than fat tissue.