If you don't mind I may say something to this.
Gymnastics is in no way any safer than cheerleading, that's for sure, but it seems that as a whole, gymnastics coaches are more equipped to deal with the constant strain the sport is putting on a body. There are gymnastics gyms that push young bodies too hard, in some cases avoiding regular puberty all together, and there are some that allow puberty to run it's course, and deal with the consequences (generally if a gymnast goes through puberty and tries to do the same skills, they won't be able to, as they've learned to control a much smaller and different body). The long hours put in are beneficial if the child has a true passion for the sport. If the child wants to follow gymnastics through to it's highest level, the long, painstaking hours are necessary, however many people put their children in competitive gymnastics who are only wanting a recreational activity for them until they are tweens/teens, in which case it's rather harmful (although there is still quite a lot of time afterwards to rehabilitate the body)
