All over the world men and women and boys and girls enjoy sports. Sports help people to live happily as well as keep fit. Today I' d like to say something about one of the most popular sports--jogging. The National Adult Physical Fitness Survey showed that 6.5 million adult Americans jog for exercise. The popularity of jogging has been heightened by medical claims of the benefits derived from regular participation in this activity. Regular jogging is credited with promoting a 'training effect' that conditions the heart to do more work with less effort increases the efficiency of the respiratory system by strengthening the muscles that as sist breathing increases blood volume in the body, thereby increasing the oxygen - carrying capacity of the circulatory system promotes blood vessel flexibility aids the digestive system and helps to maintain proper body weight through the high calorie expenditure. It is reasonable to assume that the number of adult joggers will increase if this activity is properly taught and encouraged through school physical education programs. Children should be taught how to jog as well as to understand the benefits that result from regular jogging h is recommended that motivational programs such as the National Varsity Club Sport Award be utilized to pro vide added 'incentive for school jogging programs, In addition to learning the physiological effects of training noted above, students should be given the following information as guidelines for their personal jogging pro grams. When jogging, run in an upright position, avoiding the tendency to lean. Keep your back as straight as you can and still remain comfortable, and keep head up. Don't look at your feet. Hold arms slightly away from body, with elbows bent so that forearms are approximately parallel to the ground. Occasionally shaking and relaxing the arms and shoulders will help reduce the tightness that some times develops while jogging. Periodically taking several deep breaths and blowing them out completely will also help you to relax. It is best to land on the heel of the foot and rock forward so that you drive off the ball of the foot for your next step.. If this proves difficult, try a more flat - footed style. Jogging only on the balls of the feet, as in sprinting, will produce severe leg soreness. Keep steps short, letting foot strike the ground beneath the knee instead of reaching to the front. Length of stride should vary with your rate of speed. Breathe deeply with mouth open. Do not hold breath. If for any reason you become unusually tired or uncomfortable, Slow down, walk, or stop. How many adult Americans jog for exercise according to The National Adult Physical Fitness Survey ?