I think broken bones or brutal-looking body checks in hockey are not the real problem. Body-checks probably don't even hurt very much, and broken bones heal. The biggest problem for NFL players are repeated small concussions, which seem to have a devastating long-term effect. In addition, the obesity required in some positions takes its tolls. The life expectancy for NFL players is, according to some studies, as low as 52 years for linebackers, and 55 on average. Encouraging kids to play football seriously should be seen about as responsible as encouraging them to smoke.