Heres the story, my lil bro (14 yr old) has seen me train and says he wants to start training too, but since he's on his 9th grade football team he insists on lifting weights along with training. I've told him that I just do calisthenics and I'm fine, but he's insisting. After thinking about it i researched it a bit and was surprised to find that lifting weights can benefit you alot if you do it properly. I've had it drilled into me that weights make you too "bulky" and "slow" in boxing from a younger age, so Im taking this in with some skepticism. Now i turn to you guys for answers, if lifting ISNT bad for grapplers and striking (boxing and wrestling, but I started BJJ recently) then I might lift along with my brother. PS. Also could he be too young for lifting, hes pretty tall for his age (6ft even) but still skinny, he hasnt filled out yet at all. And by skinny i mean like 130lbs anorexic skinny. I on the otherhand HAVE filled out and am sitting at 6'2, 170lbs.