SATURDAY, Sept. 11, 2004 (HealthDayNews) -- It's the mantra of the exercise gurus everywhere: Stretch before you exercise, stretch after you exercise, and you'll avoid injury.
Sounds like good advice, but a growing body of research suggests it's wrong.
While stretching doesn't seem to be harmful in general, it typically isn't worth the time or effort, said Dr. Stephen Thacker, co-author of a new study examining research on stretching.
"It's not so much that stretching will injure you. It's that it doesn't do anything," he said.
But the views of Thacker and others are far from widely accepted, and many exercise experts continue to recommend that athletes and weekend warriors devote some time to stretching.
"The jury is still out," said Werner W.K. Hoeger, director of the Human Performance Laboratory at Boise State University.
At issue is whether the stated purpose of stretching -- to boost flexibility, thus reducing the chance of injury -- is ever actually accomplished. U.S. researchers set out to find the answer by examining six previous studies that explored the benefits of stretching. They reported their findings in the March 2004 issue of the journal Medicine & Science in Sports & Exercise.
"What we found was that stretching prior to competition or other physical activity did not prevent injury," said Thacker, director of the Epidemiology Program Office at the U.S. Centers for Disease Control and Prevention. "We also found that stretching prior to activity could have a bad effect. You might not jump as high or run as fast."
Thacker acknowledged his study didn't look at two areas where stretching might be beneficial -- in the short periods between competitive events and during physical therapy. But the time between competitions doesn't have much to do with typical exercise, he said. "That's not right before you're going to go run your 5K or play in your basketball game," he added.
Overall, the researchers said there isn't enough firm evidence to recommend stretching or fully reject its usefulness.
But they did find plenty of evidence that warming up -- actually exercising muscles instead of stretching them -- helps boost flexibility and performance. "If you're a jogger, start slow," Thacker said. "If you're a golfer, start with some easy golf swings."
But even flexibility might not be all it's cracked up to be. A 1999 study of 303 military recruits found that both the most flexible and the least flexible were at highest risk of injury.
Not surprisingly, stretching still has plenty of defenders. The problem with existing research is that it isn't strong enough to debunk stretching, Hoeger said. Ideally, researchers would follow a few thousand people for several years to see how stretching affected them, he said.
"The problem we have is that that kind of research is very time-consuming and lengthy," he said. "A lot of people haven't shown an interest."
To make matters more complicated, no one knows what the ideal level of flexibility is for, say, a quarterback or gymnast, Hoeger said.
Some activities -- like gymnastics, dance, diving and swimming -- seem to require more flexibility, while sports like basketball and volleyball don't, he added.
Hoeger recommends that people continue to stretch. "We need to keep in mind that flexibility should be an overall component of your conditioning program."
These stretching tips come courtesy of the Women's Heart Foundation:
- The proper way to stretch is slow and relaxed. Don't bounce because this can cause you to pull the muscle you're trying to stretch.
- Don't overstretch cause it might cause damage. Only stretch to the point of mild tension, and ease off if the stretch feels painful.
- Maintain the stretch for a minimum of 15 seconds each, without bouncing. Breathe slowly and naturally.
More information
Get details about exercise and stretching from the Mayo Clinic.
