People who exercise won't necessarily live longer. Exercise improves cardiovascular and respiratory function, making you feel healthy and energetic, but it also increases metabolic rate, which accelerates cell division. The number of times normal somatic cells can divide is limited, commonly known as the "Hayflick limit," averaging about 50-70 divisions. The faster the cells divide, the sooner they die. Longevity is most heavily influenced by genetic factors. If you want to live longer, the best approach is to eat less and move less, lowering your metabolic rate—like practicing a slow and steady retreat.