As a member of the Beltway Betties of NOVA Roller Derby, Renee Mitchell skates under the name Missy Savage and has had some meaningful bouts as a blocker for her team. Skating 3 or 4 times a week and competing at a high level, however, has not come without its challenges.

After all, roller derby involves full contact and high-intensity plyometrics with lots of hops, lateral motions, and quick reactions. [See "A Quick Look at Flat Track Roller Derby" on the facing page.] Plus, in roller derby the track is relatively small—typically 108 feet long and 75 feet wide—and the sport involves abrupt movements combined with forceful contact. This often leads to sudden falls and athletes sliding off the track. Players get hurt.

"I've sprained my left ankle twice and my right ankle once," Mitchell says. "Most recently, I had a level 4 sprain that required time off and lots of healing. It led me to visit a physical therapist for the first time."