Weight training could be offered to girls as well as boys but it would have to be modified to be more accepting to females.
Explanation:
Weight training has been a boys-only thing for a very long time and it has been adapted to fight the male body and its physical capabilities. If they were to offer it to girls now in its current state, it wouldn't be as accepting of a class. It would cause harm to the girls and some of that harm would be temporary and some could be permanent. As much as it would be right for weight training to be offered to girls, it will take some time and adjustments before it could happen.
I think this experimental method is a better option because its in a natural environment where the kids dont know whats happening unlike the suveys where you ask them questions which is probably a bad idea because they might feel scared and just change their minds.