I am almost 55 and I still play basketball and dek hockey. The only thing keeping me going is weight training. I do like 8 sets legs and 7 sets arms. Only do it a couple times a week. It helps me recover from injuries. I hate doing dead lifts at my age but I swear it really helps correct muscle imbalances I might have. But every one is different. A physical therapist could probably help you more than a doctor could unless you are convinced there is something structurally injured. Good luck.