Believe it or not, there is an art and science to losing weight through exercise. Have you ever wondered why some people exercise a little and they look great, while other seem to exercise all day long and they look like they have been sitting on the couch eating potato chips instead? There is a direct relation to how you exercise and what your body uses for fuel.

During exercise, the body uses mostly fat and carbohydrate as fuel. Protein is spared from acting as fuel, because the body keeps it in store in case you begin to starve. At low levels of prolonged exercise, our energy needs come from fat. Carbohydrates come more into play with higher-intensity, short-duration exercise.

Adequate protein intake is crucial for maintaining your lean body mass to enable you to perform at your best. The source of energy and efficiency depends on what you ate before you started exercising and the intensity and duration of the exercise. Professional endurance runners will often carbo-load on pasta the night before a big race because they know that is the best fuel for their specific exercise.

Fat as a fuel provides extensive stores of calories in an easily portable form. Fat weighs much less per unit calorie than protein or carbohydrate, however, carbohydrate is more efficient than fat. This is why it is difficult for people to exercise while trying lose weight on one of those high-protein low carbohydrate fad diets. It doesn't provide your body with proper fuel to burn.

The best nutrition you can give your body for exercise is soy-based protein meal replacement shakes with multi-vitamin supplements to target your specific needs. Just as there is an art and science to exercise, there is an art and science to fueling your body for exercise. The better the nutrition, the easier it is to exercise, lose weight and keep it off for good.

For a performance athlete, it is important to maintain the efficiency edge provided by carbohydrates. Under usual exercise conditions, protein provides only about 6% of energy needs. The only food that provides energy for short-term fast-paced exercise is carbohydrate, while slow, steady aerobic exercise uses all three primary fuels.

Vigorous exercise involves minimal risks for healthy individuals, but can be risky for couch potatoes. You did not put on all that weight in a day, so you can't expect to go out and run ten miles the first time you try to lose it. Gradually work up to a realistic goal, and celebrate your small daily accomplishments. (With a pat on the back and not a donut, of course!)

The more you exercise, the more muscle you will build as well. Remember not to get hung up on weighing yourself because muscle weighs more than fat. You may see the scale begin to increase while your stomach is decreasing. This is a good thing. It's much more important to focus on how you feel more than reaching a number in pounds.

The more you exercise, the more you will lose fat and the more important it will be to get good carbohydrates to fuel your body for exercise. You don't want to get to the point where your body is robbing itself of protein for fuel. Don't be afraidto eat fruits and vegetables, cereals with grains, etc while you are trying to lose weight with exercise. The worst thing you you do is not eat anything.

So there really is an art and science to exercising, and what you fuel your body with is in direct relation to your desired level of activity. Small changes in your diet targeting your exercise can make the difference between success and failure in your weight loss efforts. No matter what you choose to do, always remember to feed your body with the best nutrition possible.