(HealthScoutNews) -- People who make stretching part of their workout rituals may be pulling their legs if they think it helps reduce muscle pain and injury from exercise.

That's according to Australian researchers who reviewed a roster of studies looking at the benefits -- or lack thereof -- of stretching.

When taken together, five studies showed only a trivial reduction in muscle soreness from limbering up before or after working out -- about 1 millimeter on a 100 millimeter scale.

"Most athletes will consider effects of this magnitude too small to make stretching to prevent later muscle soreness worthwhile," according to the researchers, who report their findings in this week's British Medical Journal.

The researchers, from the University of Sydney, also could find no statistically significant protection from stretching before exercise against injuries like ankle sprains and muscle tears in two studies of army recruits.

The effect for the recruits was so small, they say, that a person would have to stretch for 23 years to avoid a single injury. Since the typical athlete faces a smaller risk of injury than a solider in training, the benefit from stretching for them, if it exists at all, is probably even slighter.

Still, the scientists add, "It would be particularly interesting to determine if more prolonged stretching carried out by recreational athletes over many months or years can produce meaningful reductions in risk of injury."

Dr. Thomas Best, a sports medicine expert at the University of Wisconsin, says the Australian study is in synch with other research -- including his own experiments with animals showing that stretching doesn't strengthen muscles or tendons or make them more resilient.

"Why is it that a professional football player strains his hamstring, or an elite sprinter does, when they're flexible, strong and well-conditioned?" says Best, who co-wrote an editorial accompanying the journal article.

Dr. Ian Shrier, a McGill University sports medicine specialist, says stretching before a workout may, in fact, make muscles more vulnerable to injury by tearing their fibers. What's more, despite popular perceptions, nearly all workout strains and pulls occur not when a muscle hits its limit of extension but when it is contracting -- so widening its range of motion has no theoretical reason for reducing the chances of harm.

"I would like to see people move from stretching to a much better warm-up," says Shrier, of the Center for Clinical Epidemiology and Community Studies at McGill's Sir Mortimer B. Davis Jewish General Hospital in Montreal.

Although Best and Shrier agree that stretching isn't the insurance policy against injury that people believe it to be, neither doctor is ready to discard it completely. Shrier says improving flexibility may potentially boost athletic performance. And Best says people who are inflexible to begin with may reduce their risk of exercise injury by limbering up before working out.

If you insist on stretching, Best adds, it probably won't hurt and it can feel good if done properly.

What To Do

For more on stretching, visit the American Academy of Orthopaedic Surgeons. You can also check the Nicholas Institute of Sports Medicine and Athletic Trauma.

Reference Source 101

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