I asked here, and elsewhere, about when a kid should start lifting "heavy".
One of my sons started at 11 or 12.
Always a big kid,100# at 6YO, 200 at 12, but at that point, we was getting sloppy, but VERY strong for his age, even before he started lifting weights (lots of hay bales and wood splitting
)
Any way, started BJJ at 11, and started running, hard. Started football at same time. I kept him lifting "light".
Right after he turned 14, blew out a knee in BJJ, so I asked all the Docs we were seeing about age to lift heavy.
Was told if he was thru puberty and leaned proper form, he was GTG, so he go'd.
Hit the 1000 lb club while still 14, and now since football ended last fall, he lives at the gym.
He's become obsessed, which is actually starting to concern me.
Trying to get him to back off a bit, and return to BJJ ( he stopped in August when football practice began)
Selling it as crosstraining/improving flexibility, and hope I can talk him into it.
And I'm having a hell of a time getting his younger brother to START lifting: I think he doesn't want to take up something his brother excels at. He also dropped BJJ.
FWIW, I started lifting again 3 months ago, after a 30 year break!