How can excessive exercise affect your skeletal system?

Many things can put your skeletal system at risk-falling off a bike, slipping on a patch of ice, machetes. But one thing that has the most potential for damaging your skeletal system is one of the factors so important to your overall health: physical activity.

Though we can generally identify the things that are good for us in extraordinary amounts (vegetables, $100 bills) and the things that aren't (overdue bills, corn dogs), physical activity is one of those things that's a little less clear. Certainly, physical activity helps our entire body-our heart, brain, and our bones-but the catch is that when it comes to your bones, joints, and muscles, excessive amounts of physical activity can be just as destructive to your body as a boxer's right hook.

Consider what the fittest man in American politics says about the subject. In his prime, Arnold Schwarzenegger was the stereotypical icon of fitness-a muscular and lean athlete with less body fat than radish-addicted supermodels. With open-heart surgery and shoulder surgery now behind him, the honorable Terminator (or Governator, to Californians) acknowledges that his body is slowing down with age and because of his past. Though he's not a doctor, his diagnosis is dead-on.

Schwarzenegger says all the super athletes he knows in their 40s or 50s-himself included-feels like they've slammed a wrecking ball into their bones and joints because of all the stress they endured throughout their around-the-clock training and competing.

Though elite athletes may be fast, skilled, and strong enough to juggle Hummers, the price they pay comes later, because their bodies (even if they compete in non-contact sports) can't handle the constant battering. Joint deterioration can plague super and professional athletes who put an excessive amount of pressure on them throughout their careers.

I know it's a hard concept to imagine when today's athletes look like they're chiseled out of granite. But the reality is that excessive exercise is like a category-5 hurricane to your body. The more pounding you take-even if you aren't a super athlete-the greater the chance that the foundation of your house is going to be reduced to rubble.