Szobe, I do not doubt for one minute that supervised excercise can be beneficial.
It is the "sports" that actually are intended to provide benefits to the adults concerned rather than the children that I am concerned with.
Stupid coaches, in my experience, are not rare. The coach is pressed to provide a winning team. He is not charged with providing the maximum benefits for the students. Can you imagine the coach at WVU or Notre Dame telling his team to go out there and play a good game and have a good time. No, he sends them out to "beat" the other team. Injuries are commonplace. What do we expect?
The coach wants to win. The players are told that the school wants them to win. The recruiter pays bonuses (now or later) to winners. The alumni build new stadiums for a winning team. The tickets pay for buses, airplane rides, and short skirts. A winning team increases the colleges prestige. And all this "responsibility" is placed on the backs of children who have not yet reached "the age of consent".
We have the laws of "statuary rape" for instance that are intended to prevent sexual exploitation of children that are to young to be able to give an "informed consent".
We have no such laws intended to prevent the physical exploitation of children who are to young to be able to give an informed consent.
Consequently they are exploited. And sadly it's often not to their benefit.
As a mechanic I feel that you have to look at causuality all the way. With the priests I feel all society deserves some blame. The same tracing down the causes of the failures of my daughters knees places the blame on a society that is perfectly willing to exploit children for some percieved benefit to adults.
No decent horseman who works with horses ever lets them pull as hard as they can until they have reached their full growth. The potential for damage is too high. We do not treat our kids that well.
Whether it's "rape" or physical mauling in the name of sport it's still a selfish abuse of children.