If you've ever wondered about the rationale behind exercise for weight loss, then write-up is for you. There are two basic ways on how we can shed off those unwanted pounds in our body. One is known as thermodynamics and the other is metabolic. These two when properly understood and applied can be very effective tools in losing weight.

Put simply, we lose weight when the amount of energy that we get is less than the amount of energy that we lose. We lose energy when we do work or exercise. When the energy that we get from the food that we eat is not enough for the work at hand our body will be forced to utilize its stored energy. This state is known as negative energy balance. This means that there is a deficit of calories in the body. The total calories gained is less than what the body needs in relation to its work done.

Constant deficit of energy leads to weight loss. For example, if the total energy that is gained in a day through the food eaten is 4000 calories and the total energy that is burned by work or exercise is 4100 calories, there is a deficit of 100 calories. If this deficit will take place every day for ten days, the total energy deficit is equivalent to 1000 calories. This 1000 calories is going to be supplied by the body by burning its stored fats or calories. Hence, a constant energy deficit translates to weight loss. The bigger the energy deficit each day the more weight will be lost.

On the other hand if the energy that is acquired is more than what is being used, the body will be accumulating more calories each day and as a natural consequence, there is weight gain. For example, if the amount of energy that a person gets from the food that he eats is 4000 calories and he is only able to use up 3800 calories each day, 200 calories is stored in the body as fats. If this amount of calories is stored in the body everyday for ten days, the total amount of calories gained is 2000. This 2000 calories is packed as body fats and translates to weight gain.

In a nutshell, if you want to lose weight use more energy that what you get from food. Do exercise and make sure that you don't have excess calories that will be converted to fats. Resistance exercises are very effective routines in losing weight. This is the principle of thermodynamics explained behind exercise for weight loss.

Metabolism is the rate by which your body burns the food you eat. If your metabolism is fast, you burn more energy. The opposite happens when your energy is slow. When you exercise, you speed up your metabolism. The more you flex your muscles the faster your metabolism becomes. So, if you want to exercise for weight loss, you will essentially want to boost your metabolic rate. Constant exercise leads to toning of muscles. The more you move your muscles the faster your metabolism becomes. Your muscles will also become toned. Metabolism is fast if your muscles are toned and so you burn more energy. Fast burning of energy or fast metabolism leads to weight loss.