The researchers at Lawrence Berkeley National Laboratory in the U.S. studied 7,000
 American men to see if exercise prevented the centimeters and kilograms from collecting 
 around their middles. It didn't Even men who maintained a constant jogging schedule between 
 the ages of 20 and 50 still gain an average of 1.5 kg and added almost 2 cm do their waistimes.
 The only way to study slim and trim, say researchers is to continually increase the amount of
 exercise will age. To keep his youth figure, a man who ran 15 km every Saturday in his twenties 
 would have to run a weekly 80 km marathon in his fifties.
 Sound despairing? Even if regular exercise does not keep the spare tire off, if does 
 benefit the heart and lungs. But be sure to take care of your joints ---especially knees. 
 Wear proper running shoes, run on soft ground when possible and see a doctor if aches and 
 pain persist.