ELIZABETH COHEN, CNN CORRESPONDENT (voice-over): We all know what exercise does for the heart and muscles, but what can it do for a man's sex life?</s>UNIDENTIFIED MALE: You can exercise your way into potency. That's the key message of this study.</s>COHEN: In this new study of some 600 men, those who exercised were least likely to become impotent. They had to burn at least 200 calories a day through exercise to prevent impotence. That's about 15 minutes of jogging, 20 minutes of basketball or 25 minutes of tennis. (on camera): The more the men exercise, the better their chances of avoiding impotence. But at a certain point the effects wore off. When men burned more than 850 calories a day exercising, their chances of becoming impotent went back up again. Burning 850 calories would mean, for example, spending about 2 hours a day on the stair master.</s>UNIDENTIFIED MALE: So as it is in all of life, moderation in exercise is still the best bet.</s>COHEN (voice-over): So why would exercise help a man's sexual performance? The theory is that just as exercise improves blood flow to the heart, it could help improve blood flow to other parts of the body as well. The study found it's never too late to start exercising to prevent impotence, but that exercise won't help reverse impotence if it's already happened. For "Feeling Fit," I'm Elizabeth Cohen.
Exercise Can Help Prevent Impotency