What will happen if i run a LOT and strength train a LOT..doesn't running make you weaker, and lifting make you slower?

Running doesn't do anything for the upper body, but it does strengthen the lower body. Well, actually, running strengthens some muscles more than other muscles, so you need to do stretches to strengthen your muscles. Here are the stretches I do. Web searches will give you links to other stretches. Running and weights go well together if you do them on different days and if you don't over do it in either activity.