Common sense says the more an athlete utilizes all of her/his body, the fewer injuries. Many injuries are caused by overworking certain muscles and joints, and they just get tired and worn out of the overload. Constant sport-specific training is leading to a lot of these injuries, especially in kids. And they are seeing more and more fractures to the spine because athletes, again, especially kids, do not strengthen the core enough to withstand the stress they put on the spine. I know four kids, all of whom are 15-16 years old, who all have or have had stress fractures in their backs, all in the last six months. It's crazy...