Stretching Introduction

Stretching seems like such a straightforward topic that you may expect us to explain it in a sentence or two and then show you a stretching routine. Well, as it turns out, a lot of confusion surrounds the subject of stretching. The American College of Sports Medicine (ACSM), one of the most respected sports and fitness organizations in the world, provides guidelines on how to stretch, but the organization still admits that more research is needed to determine exactly what stretching can and can’t do for you.

Stretching lengthens your muscles and loosens up the joints that your muscles connect to so you can move more freely but still keep your joints stable. Too much flexibility leads to unstable joints; too little flexibility leads to restricted movement. When your muscles are at their ideal length, you can walk without stiffness, reach down to tousle a toddler’s hair, or turn around when someone calls your name — everyday movements that you take for granted until you have trouble doing them. When your muscles and joints lack flexibility, you feel tight.

Two stretching methods we describe in this section, Active isolated and PNF, actively stimulate the nervous system to increase the release of muscular tightness. With these methods, you hold stretches for a shorter period of time than you do with traditional stretching, and you contract the muscle ultimately to encourage more relaxation.