A roller—which looks like a firm log—can be a valuable part of a healthy runner’s warmup and cooldown routine, says Michael Clark, Ph.D., a physical therapist and CEO of the National Academy of Sports Medicine. Rolling improves circulation, which gets the body ready for a workout and helps it recover afterward. And because rolling breaks down knots that limit range of motion, it preps muscles for stretching. Try these routines, moving slowly and stopping and holding on tender spots.