Have you ever considered yourself a body builder?  Body builders are very disciplined in their approach to beefing up.  Their goal is to work each muscle to get it to its optimum working condition.  It takes more than big arms to lift something heavy.  It also takes a strong back.  Each part has an important role to play.   We really don’t know how important a part of our body is until it is injured.   When I had my appendix out, I first realized how much your stomach muscles are needed when you sit down.  I thought it was mostly legs.  God knew what He was doing when He gave us so many parts.