It’s been a long, hard day at the office, and you need a good workout to blow off all that stress. But before you hit the free weights, the stationary bike or the elliptical machine, you spend 10 minutes carefully stretching all those stiff muscles, just as every coach, trainer and physical therapist has advised for as long as you can remember.
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Now the question is why ?
There’s no evidence that you’ll prevent injury. In fact, some people believe you’re more likely to cause one.
“There is not sufficient evidence to endorse or discontinue routine stretching before or after exercise to prevent injury among competitive or recreational athletes,” concluded the National Center for Injury Prevention Control, part of the Centers for Disease Control and Prevention, in a 2004 study that may be the most thorough look at the research on stretching.
Research and anecdotal information attribute many benefits to stretching: reduced muscle tension, improved circulation, pain reduction and management. Perhaps most important, stretching helps us maintain range of motion as we age, allowing older people to continue with the activities of daily living.
The question is whether “static stretching” — the most common type, which involves holding a muscle in one position for a defined period of time — has been misinterpreted, or oversold, as a preventive for what ails you.
“People believe all kinds of amazing things, and it changes every 10-15 years,” said William Meller, a physician and associate professor of evolutionary medicine at the University of California at Santa Barbara. The merits of stretching are “not based on any science. It’s spread by coaches, trainers and all kinds of people.”
According to Julie Gilchrist, a medical epidemiologist who helped conduct the CDC study, “it’s probably important that we maintain some norm of flexibility throughout our life spans, but I don’t think anyone has really defined what that (norm) is.
“Our belief is there are probably people who would benefit from stretching. But then the question is who should stretch, when to stretch,” how much to stretch and, most important, what benefits can be expected.
Even for the elderly, “we don’t have the kinds of controlled intervention studies that we need to make a definitive statement about the benefits of doing flexibility exercises,” said Chhanda Dutta, chief of the clinical gerontology branch at the National Institute on Aging.
Similarly, coaches wouldn’t dream of putting athletes on a field, even for practice, without a battery of stretches that help them take the pounding and awkward landings of contact sports.
“As a coach, if I didn’t do that and somebody got hurt, I would probably have a tough time sleeping at night,” said Paul Foringer, a football coach at a high school in Gaithersburg, Maryland. “It’s kind of common sense. If you take something that’s taut and tough and you yank it, you’re going to tear it.”
But that’s not what studies show. “Stretching was not significantly associated with a reduction in total injuries,” said the CDC study, “and similar findings were seen in the subgroup analyses.”
In static stretching, “you’re taking the muscle to the point where it naturally wants to go, and then you’re taking it a little bit farther,” said Meller. That produces microscopic tears of muscle fibres and does nothing to prevent injury, he said. It also may weaken the muscle slightly, increase the possibility of injury and inhibit performance, according to him and the CDC study.
For those who want to stretch, it should be done after a warm-up or at the end of an exercise routine because warm muscles are more pliable.
Research indicates that warming up before exercise is more valuable than stretching. Specifically, Meller said, you should spend three to five minutes gently putting your body through the actions you’re about to perform, slowly increasing the intensity. If you’re going to play tennis, he said, swing forehands, backhands and serves, and run forward, backward and laterally before you hit the first ball.
Source: The Washington Post