As we all know, running has many benefits. The fitness coach will tell you that this is a high energy consumption fitness exercise, especially to enhance the human body's cardiopulmonary function is very helpful. And running is also the most commonly used way of physical exercise, because running technology requires simple, no special venues, clothing or equipment. Running can be done on the playground, on the road, in the park and in the woods. Each person can also master the speed, distance and route of running by himself. Running outdoors in the morning or evening can absorb more fresh air. The medical profession believes that people who insist on running for a long time seldom feel joint pain and are not prone to arthritis when they are older. Moderate running 32 kilometers a week is the best exercise for the body. In the long run, there is no doubt about the heart benefits of running. Of course, there are other benefits of running, which can sober the mind, make the body produce more endorphins (an analgesic hormone), and make people happy. But all these benefits are based on the correct running posture. On the contrary, the damage of running to health can not be neglected, especially the injury of running to joints. Varus foot usually occurs in three groups of people: one is flat foot, because the arch of the foot lacks sufficient support, so it is easy to turn inward. In fact, it is not necessary to use professional instruments or to self-test whether it belongs to flat foot. First, it can be observed by naked eyes. Flat foot refers to the lower arch of the foot. Or standing in sand and water marks, it can be judged that the foot shape of high arch usually has an obvious inward depression at the arch of the foot, while flat foot does not. The whole foot shape is basically oval. The second situation is that tall people tend to turn in when running because of their heavy weight; the third is women, because of their unique physiological characteristics, the crotch is wider, so their legs are usually Q-shaped, and their weight is more on the inside of the knee. Bias pressure on the inside of the knee causes impact on the heel, ankle, knee and waist when landing, causing damage to various parts of the body. When young, because thigh muscles are strong and play a supporting role, and knee meniscus is thicker and softer, can form a buffer, may not feel this wear and tear. But with age, muscle strength and meniscus thinning and hardening, weight directly impacted on the knee, the damage will gradually manifest. Therefore, how to correct running posture and foot shape has become an important content to avoid running injury. Choosing the right pair of running shoes is crucial. This requires padding the arch of the foot so that the knee is evenly stressed to avoid varus. Doctors also say a comfortable pair of shoes is essential to reduce friction. Doctors also emphasize that it is best to run on a soft and straight road, because it can reduce the impact of the road on the body. From this point of view, the treadmill has a strong impact on the knee joint because of its hard bottom, which is easy to cause knee joint injury. Therefore, people with poor joints are better off using less treadmills. In addition, any sport needs to be moderate and gradual.