Textured massage balls and vibrating foam rollers have turned traditional stretching tools into revitalizing necessities for runners. That’s because stretching and mobility work improve run performance more than you realize. These tools don’t always directly affect muscles and joints. Instead, they help loosen the tension in your fasci a with “self-myofascial release” or self massage.

Fascia is the fibrous tissue that runs throughout the body. If you’ve heard, or suffered from, plantar fasciitis, you know how important it is to have healthy and pain-free fascia to allow for everyday movement and easier running, Kelsey Kerr, NSCA-CPT, director of training and experience at StretchLab in Irvine, California, tells Runner’s World .

Many tools designed to improve flexibility do so by directly releasing tight fascia.…