Joe DeFranco stated he was bench pressed 225lbs for a 1RM when he was in 8th grade.
12 years old is a great age to start lifting and getting stronger. While all the other kids are doing curls and bench presses, teach your son to train his whole body and why he should train his whole body.
Have him do deadlifts, squats, front squats, power cleans, bench presses, bent over rows, overhead presses, dips, pullups. While his whole body is getting bigger and stronger he will be looked at as top of the line for his age.
I plan on getting my son into powerlifting and Olympic weightlifting when he's around 12.
I remember my first 1RM attempt at 13 years old was 125lbs and I weighed exactly 125lbs at that time. I remember about twelve weeks after that I bench pressed 165lbs at 133lbs as a fourteen year old. I can only imagine how strong I would be today if I would never stopped.
Personal Trainer- ACE, NASM AFPA; Nutrition Consultant- AFPA
"I can do all things through Christ which strengtheneth me." - Philippians 4:13"