For years, I thought if I set foot on a field without stretching first, I'd risk injury-induced benchwarming. This rule was reinforced by many a baseball coach, not to mention my own body type, which is about as pliant as cold concrete. I was tight, therefore I stretched. But in the past few years, many exercise scientists have sworn off static stretching (e.g. the hands-on-ankle quad tug), citing new studies that show it doesn't prevent injury or decrease post-exercise soreness—and that it can decrease muscle power. The Gatorade Sports Science Institute dedicated an entire newsletter to debunking stretching's benefits; I just finished arguing with a University of Minnesota kinesiologist who spoke of stretching the way I'd speak about castor oil. But the thing is, stretching makes me feel good. And yoga and Pilates are basically advanced forms of stretching, right? What gives? I asked Andy Pruitt, founder of the Boulder Center for Sports Medicine, who lectures frequently on the myths of stretching, to cut through the fog. Here are his new rules of getting loose.

Get the Facts
There is no convincing evidence supporting the notion that static stretching prevents injury. But it may make you feel good. That's fine. Just warm up first.

Never Stretch Cold
Ever. The purpose of stretching is to lengthen tendons at the end of a muscle. Stretch cold and your muscle won't go to full length; you won't access the tendons. Always warm up with some light cardio.

It Shouldn't Hurt
If it does, you might be doing damage to your muscles or tendons. When you heal, you'll build up scar tissue, decreasing range of motion. Never do ballistic stretches—the bounce-to-touch-your-toes kind. If you bounce far enough, you can hurt yourself.

Know Your Range
Range of motion, that is. If you're a jogger, you probably don't need to stretch, because you have the range you need. But if you're playing soccer, a slide tackle might knock you into an awkward position, like a half-split. You want to make sure you can reach that extended range; stretching is one way to do this.

Go Dynamic
Another smart way to improve range of motion is with dynamic stretching, which allows you to lengthen your tendons while warming up with sport-specific movements. Examples include butt kicks, lunges, and karaokes. But don't start doing this until you get some basic instruction. Watch a short dynamic-stretching instructional video at outsideonline.com/dynamicstretching

Get a Stretching Rx
If you think you have a limited range of motion from a past injury, talk to a physical therapist or sports physician. One thing they might suggest: PNF (proprioceptive neuromuscular facilitation) tretches,which are often done with a partner. With this kind of stretching, the muscle contracts and then relaxes, allowing you to really access the tendon.

Be Realistic
Like me, you probably have about ten hours a week for sports. It's a question of priorities: If I have the range I need to cycle, am I going to spend one hour stretching? No. I'll be riding.