Stretching 'fails to stop muscle injury'

The England cricket team warm up

Scientists have cast doubt on the benefits of stretching before and after exercise as a way of reducing soreness and the risk of injury.

Stretching routines before and after exercise are common practice among sportspeople and casual gym users alike.

Like many good ideas, the muscle spasm theory of muscle soreness was wrong

Dr Rob Herbert

But a review of research by scientists in Australia suggests the benefits may be minimal.

The researchers examined five studies, three which evaluated stretching after exercise, and two looking at stretching before.

These showed that stretching reduces soreness by such a small amount that most athletes would not consider the effect worthwhile. Neither does it significantly help to prevent injuries.

Data from two studies on army recruits in training, whose risk of injury is high, show that muscle stretching prevented on average one injury every 23 years.

Most athletes are exposed to lower risks of injury so the absolute risk reduction for most athletes is likely to be smaller still.

Discredited theory

Researcher Dr Rob Herbert, from the University of Sydney, told BBC News Online the belief that stretching reduced injury first came to prominence in the 1960s.

The theory was that muscles were more likely to spasm, and cause pain, if they were suddenly called into vigorous action.

Dr Herbert said: "It sounded like a good idea, and the timing was perfect - around the time we were learning that physical activity reduced risk of heart disease, so recreational exercise was becoming very popular.

"But like many good ideas, the muscle spasm theory of muscle soreness was wrong and has since been discredited, but the practice of stretching before exercise persists."

Dr Herbert said it was possible that a gentle warm up before strenuous exercise may reduce the risk of injury - but even this was far from certain.

"There is no proven way of preventing muscle soreness associated with unaccustomed exercise apart from repeated performance of that specific type of exercise.

"With unaccustomed exercise, people get sore, but with repeated performance of the exercise they become resistant, for a time, to the muscle damage that causes soreness.

"It appears that the only way to prevent soreness is to get muscle soreness."

Support

The research is published in the British Medical Journal. An editorial in the same publication backs Dr Herbert's belief that although stretching is widely thought to be beneficial, there is little hard evidence to support the theory.

Dr Domhnall MacAuley, a GP in Belfast, and Dr Thomas Best, of the University of Wisconsin, say: "Some of the basic principles of caring for acute injuries of the soft tissues have never been questioned, yet there is often little evidence to support common practice."

Professor Graham Smith, a clinical physiotherapist based in Glasgow, told BBC News Online the best way to minimise the risk of injury was to keep the muscles conditioned by taking part in exercise regularly.

However, he said a sensible warm up, which involved gradually building up the level of physical activity was also sensible.

"You cannot just touch your toes and think you are fit to play," he said.