Gymnastic, weight training for children and teenagers

I've seen that coach Sommer train athlete since they are very young...doing fsp and fbe which mostly consist of strength training. I'd like to ask coach and senior member here if is it okey to apply weight training (strength and conditioning) to children and teenager?

Because most people said that weight training can make children not grow tall, is that true? And why is that?

Coz I see that a lot professional gymnast grow tall enough and they train gymnastic in very young age.

Or Is there any different between strength training with gymnastic way and weight training?

I also read the book "stretching scientifically" it is said that isometric static stretching is not recommended for children,coz isometric stretching is a kind of strength training also.

Thank you

Isometric stretching is not recommended for people younger than 18 years (Though I'm 17 and I'm starting with PNF :roll: ) And any strenght training does not stunt growth of children or teenagers, that is a myth.

So it is all just a myth rite.....ok

Thank you Falcon