In Indianapolis, the Soap Box Derby, a sport where children and teens race motorless cars down a sloped track, has been active since 1936, just two years after the race began in Ohio.
"We see lots of kids who are just doing the same sport all year round, and that definitely can lead to overuse injuries," said Dr. Joel Kary, a sports medicine physician at St. Vincent Sports Performance.
Blood centers target young donors for several reasons: Early donation often leads to lifelong participation, and school blood drives are very productive, studies show.