Running for 20 minutes a day is useful and can exercise your body. Running for 20 minutes a day promotes metabolism, can exercise the body and keep the body healthy. Running is a relatively common way to exercise the body, running for 20 minutes a day can exercise the leg muscles, thus playing a fitness effect. Regular running can make the bones maintain in a healthy state, enhance physical fitness. But it should be noted that although running is a good aerobic exercise. But it is not suitable for over-obese patients, over-obese patients if forced to run, it will affect the knee joints, resulting in knee injuries and other conditions.