Running breeds weaknesses. Or, rather, if our body had its way with things it would be more than happy to let our stronger muscles pick up the slack of the weaker ones. The human body is a master cheater, relying on what’s already strong because it takes more work to change and improve what is not. Same thing in training, right? Not so easy to keep getting faster!
However, allowing this cheating to occur will always come back to bite you in the — potentially weaker — gluteus maximus. Imbalances lead to over-compensation, and at a certain point the muscles, tendons, ligaments and bones being forced to work double time will reach their breaking points, i.e., injury. Further, if you come back from that injury without still not having addressed those imbalances you’ll only wind up hurt again, and thus stuck in a vicious cycle.