It's incredible that Nadal and Federer were able to hit the ball as hard and with as much accuracy at 9pm as at 9am. Unfortunately, for most of us, overuse of a particular body part often results in pain or injury.
Flip-flops are fine for the beach or the pool, but overuse can lead to a variety of other problems. Their lack of support can lead to more severe injuries such as ankle sprains or fractures.
Tendonitis affects just about everyone sometime in their life. Whether it's the rotator cuff, patellar tendon, or tennis elbow, it is usually the result of overuse of the affected tendon.
While basketball fans let out a sigh of relief when it was reported that Lebron James' ankle sprain was minor, for many weekend warriors and part-time athletes, ankle sprains can be much more serious.