Are They Pulling Our Leg?

Much of what we know or think we know about fitness isn’t based on science. Take stretching.

Trainers and coaches tell us that taking a few minutes to stretch before and after exercise will prevent soreness and injury and improve our ability to play the game or lift the weight. But Australian researchers have reviewed studies considered scientifically reliable and found that this revered practice does little to protect us from harm.

Since 1949, only six studies on muscle soreness and two on injury risk have passed scientific muster, the researchers found. After analyzing the data on soreness, they concluded that the beneficial effects were so small that stretching couldn’t be considered worthwhile. The studies were all performed on healthy young adults who typically stretched for five to 10 minutes. Analysis of the two injury studies, both done on army recruits, revealed an insignificant decrease in risk. “On average a person would have to stretch [before and after exercise] for 23 years to prevent one injury,” says Rob D. Herbert, a coauthor of the study and lecturer at the University of Sydney’s School of Physiotherapy in New South Wales, Australia.

The study, published in the Aug. 31 issue of the British Medical Journal, also attempted to determine whether stretching improves athletic performance. There aren’t enough studies even to speculate on that aspect, the authors found.

Although there is a paucity of research on stretching, the analysis challenges what is considered one of the fundamental principles in athletic care, say Dr. Domhnall MacAuley, an Irish doctor, and Dr. Thomas M. Best, a University of Wisconsin orthopedic expert, in an editorial accompanying the study. They suggest the need for more research on modern athletic practices that have little or no scientific support. “Sport is rife with pseudoscience, and it is difficult to disentangle the evangelical enthusiasm of the locker room from research evidence,” MacAuley and Best say.

Best points out that there still could be some benefit to stretching that research has yet to uncover. But accumulating knowledge about muscle tissues suggests that the processes affecting injury and muscle soreness are complex.

“There is controversy about this,” says Lynn Millar, a professor of physical therapy at Andrews University in Berrien Springs, Mich., who studies flexibility. The lack of benefit associated with stretching “may have to do with when the person is stretching. And

“We don’t have a lot of evidence, period,” Millar says. “But the less rapid the activity, the less we need as far as stretching. If you do light stretching on muscles that feel tight and start into the activity slowly, that will probably be fine. But if I’m going to play racquetball, I’ll probably want to jog in place and then do a little bit of extra stretching.”

Herbert says further research should examine whether prolonged stretching by recreational athletes over months and years helps reduce injury. Based on the evidence so far, it may be reasonable for most people to give up stretching before a workout, Herbert says. “On balance I think most recreational athletes could choose not to stretch, but elite athletes might still stretch on the grounds that there remains a small possibility of a preventive effect.”