“Running is definitely not counterproductive to building muscle, unless you’re looking to dramatically increase muscle mass,” says Gregory Florez, CEO of Fitadvisor.com. “In fact, as a weight-bearing exercise, running helps develop more lean muscle mass in the lower body—which also keeps your bones healthy.”
That doesn’t mean it’s a substitute for strength-training, though. “Include lower-body strength moves like squats and lunges and upper-body moves like push-ups and pull-ups to reduce injury risk, increase stamina and boost metabolism,” adds Florez.