If running's your thing, it can't be your only thing if you want to be fit.
"That's like saying you're going to get all your nutrition from a single food," says Charles Poliquin, owner of Poliquin Performance in Arizona and strength coach to multiple Olympians.
Your miles can burn off a burrito or two and clear your mind after a stressful day, but skipping strength and upper-body training can keep you from the sexy shoulders, strong arms, and overall healthy image you're after—and it can keep you from running your fastest.
"You arms set the tone: The faster your arms are, the faster your legs are going to be," says Dan Ownes, owner of Hyper Fit Training in Wall, New Jersey, and a coach for the Full Throttle Endurance triathlon team in New York. And it's not just speed—arm swing keeps propelling you forward, and fatiguing up top can end your run prematurely. "When your shoulders get tired, your legs slow down."
Keep yourself moving forward—and toward your race and physique goals—with these six strength exercises that will make you a faster, longer runner and a fitter you.