Our ambivalence about stretching stems, I think, from the faulty notion that lengthening your muscles is a pre- or post-workout anything. Flexibility is one of the three pillars of fitness, yet as a nation our reduced range of motion is exceeded perhaps only by our time spent in chairs. Reduced flexibility is often the cause behind injuries, yet it actually feels good to spend an hour busting your ass to get more flexible. Of all this there can be no doubt.
The recent rise in popularity of yoga and power yoga is a testament to the fact that people will start to truly dig stretching once you tell them to face it as a job in itself, rather than some cursory warm up. Done with some semblance of attention to the tricky goal at hand (finding the exact position of a limb needed to stretch a tight muscle both actively and passively), stretching is simply too hard to classify as a warm up. It tires you out, makes you sore, tests your will and makes sweat run down your chin. That's why the dainty little gym mats and warm-up stretching charts seem so onerous. They're underselling.
And they're wrong, too. Thanks to recent studies, we now know that stretching is vital to reducing injuries in general (it resets the structural imbalances which lead to injury, and builds the range of motion necessary to perform better), but when done before a workout it not only fails to reduce your chances of becoming injured, it may even increase them. Researchers have compared groups who stretched prior to a workout to those who did not. Not only did the stretching groups fare no better, injury-wise, in the ensuing workout than those who did not, in some cases they fared worse. The reason: Stretching is work. It makes your muscles both more tired and less responsive.
Why did we ever think stretching protected you during a workout? Early studies showed a relationship between stretching and fewer injuries in an ensuing workout. It turns out, however, that those studies weren't testing only stretching, but warming up as well, and may have in fact only demonstrated the benefits of warming up, with stretching just along for the ride. In other words, you're better off making sure you walk before running and gently ease into any exertion with unweighted movements first, rather than doing a few haphazard stretches before a workout. Stretching after a workout helps, but only in the way any flexibility training helps. So you're better off doing your stretches when you give them enough time to do them well.
Filed To: Flexibility