A new kind of exercise program is becoming more and more popular in schools,gyms and clubs around the country. It probably originated in Dr.Kenneth H.Cooper's best-seller Aerobics. With some variations,it exists at present as fitness programs,aerobic exercise,and so on. These are not the traditional physical education classes. with their calisthenics and structured sports. Nor do they cater to the person who wants to set sprint records. if you want to be the neighborhood muscle-man or muscle-woman, yo won't be interested.