Side-Leg Raisers (helps prevent running injuries)

Lie on your side with your hips and legs stacked. Lift your top leg up, keeping it straight, but point your toes inward and toward the ground to isolate the gluteus medius. Hold for 30 seconds, then release. Roll over so your opposite leg is on top, and repeat. Do three sets on each leg, working up to one minute per set. -Runner's World