I suggest you start squatting more. My science teacher who lifts almost everyday, he is a former boxer told my friends and I that squats build muscle in every part of your body. He told us that it has somethig to do with the hormones or something but he said that most people avoid squats but it's the best thing you can possibly do. my friend a who lifts every day has hit 215 now on his bench and he just turned 15 he squats alot and benches he is also on varsity everything he was starting quaterback on our varsity football team and he made our varsity basketball team which is hard to do even if your a junior so squating helped him and me alot.