Physical Education

Unit 1

1.2.4.How Activity Affects Calorie Needs
The more active you are, the more calories you'll burn, which can help with weight loss. And exercise also promotes fat loss and builds muscle. This, in turn, increases your body's metabolic rate, the rate at which you burn calories, even after you've finished exercising.
Weight loss by reducing your calorie intake without activity can have just the opposite effect: It can cause your body to break down muscle, which ultimately lowers your metabolic rate and makes losing weight even harder.
The problem of reducing your calorie intake without exercise is compounded when people go off their diets. Because they've lost muscle, they tend to regain their weight quickly and then some.
A better approach is to increase activity, which builds muscle, at the same time that you're cutting back on excess calories from food. Physical activity can also reduce stress and regulate your appetite, making it easier to curb the urge to overeat.
The amount of energy needed for any activity, whether it's raking leaves or playing a computer game, depends on three factors: your muscle mass, your body weight, and the activity itself. The larger the muscle mass and heavier the body part being moved, the more calories you use. The duration, frequency, and intensity of exercise also count.