On the one hand, the youngsters are active anyway.(3) The first reason that I would like to elaborate upon is that youngsters are active anyway. The average life of a teenager or a twenty-something already consists of activity and motion. This may be dancing in a club, walking to work, playing with friends or related to one’s work. Even shopping for clothes is rather exhausting! Thus, the young are ordinarily occupied with activity, and have less need to search for further exercise. Even without physical exercise, young people are naturally strong, able to ward off disease and face the difficulties of life with vigour and enthusiasm. Young people have a well-functioning immune system, and are generally at low risk of illness. However, the same may not be said of the elderly. Therefore the old need to exercise more than the young.