Physical training can help strengthen your body and muscles. It will make your muscles thicker, and it will burn off any fats that you have eaten in your body. If you exercise too much, though, your body will run out of fat to burn and it will start burning your muscle cells. This is why you feel a burn in your legs when you run for a while. Your body is literally burning you muscle. Physical exercise will also keep the body in shape. It will prevent unneeded fat from growing and it will keep every system running on track.
Physical training is very good for your body in many different ways.