Junior started lifting late age 14. He was a pretty strong kid and could leg press on the 45degree rack 500lbs. He weighed 130lbs. Coach said he'd be lifting close to 1000 in a year without gaining weight.

It didn't take a year. Mass stayed about the same, he went up 2-3 lbs.
I know it is the growing kid thing, but similar with another junior we suggested this coach to.
Both kids won the VOS selection TT in the 17-18 group which is about 30min.