Alright, so we would need some way of building up your muscles and bones to give you the capacity and then you would have to put in the hard yards in the gym to make them strong. There are already diseases where people have bones or muscles that grow too much so that is where I would start. Working out the genetics behind that might be able to allow me to modify you to to get bigger. Unfortunately you would always be bigger and that would present its own problems. Additionally that much extra muscle would chew through energy very fast so you would have to eat continuously or we would have to slow your metabolism. This could then prevent enough energy making it to the brain and then your in real trouble.
The point I wanted to make is the we are really balanced and the fact that we are capable of all that we are is pretty amazing anyway. We can’t fly or flip cars etc. but we can do a lot. You might have to settle for Iron Man type superpowers 🙂