Conventional wisdom has long held that stretching before exercising helps prevent muscle soreness and reduces the risk of injury, although studies have drawn conflicting conclusions. Now, a systematic review by Australian researchers suggests that the practice offers little protection (BMJ. 2002;325:468-470).

Researchers at the University of Sydney reviewed five studies, involving 77 healthy young adults, on the effect of stretching on muscle soreness. They found that stretching reduces soreness by less than 2 mm on a 100-mm scale, an effect that most athletes would consider to be too small to justify the effort, the investigators said.

Data from two of the studies, performed on army recruits (whose risk of injury is high), also suggest that stretching does not produce useful reductions in injury, preventing only one injury, on average, 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," the researchers concluded.