When you are exercising, you use more energy than when you are resting. During a fast walk, for example, you use four times as much energy/minute as you do when resting. If you walk rather fast for an hour each day, you will use 260 kcal more than without any exercise, or 17 % more kcal than without any exercise. More .
Experiments with rats show that the rats who exercise at least an hour every day have less risk of becoming overweight. However, it does not look like the calories used during the exercise are most important. Instead, the natural mechanisms for regulating food and nutritional need work better with moderate and regular exercise. The rats needed one hour of exercise per day, in order to make the normal weight control mechanisms of their body work.
Exercise also stimulates the production of beta-endorphins in the body. Beta-endorphins are substances produced by the body which have effects similar to morphine. Because of this, exercise can reduce the need for alcohol, narcotics and overeating, since these abuses also stimulate the same pleasure centres as morphine and beta-endorphins. More.
Moderate exercise will also reduce the risks for a number of other diseases More. What about very much, extensive, exercise? This is controversial. Some experts see extensive exercise as an abuse similar to substance abuse, since also when you exercise, you stimulate the production of beta-endorphins. However, experts do not agree on how much exercise is healthy, and where the limit is in terms of an unhealthy dependence on exercise.
Our recommendation to people with eating disorders is to exercise at least 30-60 minutes a day by walking, cycling, swimming, physical training, etc., in order to make the normal weight control work better.