Each of us has a physical body made of muscles, blood, bones and various other living tissue. When any of these are injured or not working properly then we get ill. Nobody likes to be ill. So it is important that we keep our body healthy.Exercising the body is one way of keeping it healthy. If we do not exercise then our muscles become weaker and we are less able to do things properly. Also the bones can become weaker and thus break easily.There are many types of exercises that we may participate in. We may play badminton, football, netball or whatever games that we prefer. We may also jog, walk, swim or climb a mountain. Older folks prefer less strenuous exercises like Tai Chi, Yoga or a leisurelystroll in the park. For the really fit young people, there are rock-climbing, gymnastics and other physically demanding activities.We exercise to keep the body healthy. However there are some who overdo things and end up injuring themselves. It is fine to jog for a few kilometres. It is madness to jog until we are exhausted. Also they are people who become addicted to their exercises. They become unhappy when they are unable to exercise or when they lose to someone in a competition.Exercise is important. No exercise may result in a weak body. Too much exercise may result in injury. Neither extremes are good. It is up to us to be sensible in exercising.