boys and girls gymnastics are completely different. Girls peak earlier than boys and therefore need the intense training earlier. Girls are pretty much done with the sport before boys are even reaching their peak. You don't want the boys to go lots of hours early on b/c they have so many more years to endure in the sport if they want to be at the top.
Oh I understand the reasoning, and it does make sense to a certain extent. Boys can't even do a lot of the higher level stuff until after puberty. But I question whether it is really necessary even for girls to train so much so young. Certainly it makes them more competitive at a younger age, but would fewer hours earlier on really preclude them from moving up as long as they did increase the hours as they got older? Chances are my son will drop out before puberty and certainly before college. But in the meantime he gets to compete in a lower pressure environment while still keeping his options open for future advancement should he decide to continue. I do think it would be possible for the girls to have that chance as well.