Stretching. It’s one of those things that we all know that we should do, but some of us very rarely do it. But is it all that beneficial? Recent evidence suggests that stretching can actually have a negative impact on delayed onset muscle soreness. Jeffrey Sankoff explains.
Written by: Jeffrey Sankoff, MD
Science and athletics have often made strange bedfellows. While it is true that science has led to incredible advances in athletic performance and safety, it is also true that science is often co-opted by marketers, manufacturers and self-proclaimed experts who support claims that at best push the limits of credibility and at worst are pure fabrications.
Occasionally, unsubstantiated claims in the absence of scientific evidence become so ingrained in the collective consciousness that when contrary evidence is found, it is dismissed out of precedence. An excellent example of this is the belief in the benefits of stretching.
Stretching has traditionally been considered a warm-up before exercise, and its theoretical benefits are numerous. Principally, stretching has been believed to improve the range of motion of joints and overall flexibility. These have been extrapolated upon to include other benefits such as improved posture and enhanced muscular coordination. Unrelated purported benefits include improved circulation, release of tension, pain relief and even lowering of cholesterol. Stretching has also been proposed as a means of preventing injury and delayed onset muscle soreness (DOMS).
While many of the benefits of stretching seem intuitive and logical, until recently, very little science had actually been done to investigate these claims. Partly, this was because stretching was simply accepted as being beneficial, and it was partly due to a lack of good methods for testing the hypotheses. In the past 10 years though, several studies have been published reporting on many of the effects of stretching, and the results have proven both disappointing and controversial.
While it is true that stretching does improve both range of motion and flexibility, this has not been shown to translate to any other objective markers of performance. Specifically, large trials have shown that stretching either regularly, or before strenuous activity, does not prevent DOMS. Stretching after exercise also does not prevent or lessen DOMS. Worse, several studies have actually shown that stretching may be detrimental to performance.
A great deal of evidence now exists demonstrating that stretching reduces both muscle strength and the ability to perform anaerobically—a condition that exists at higher levels of exertion such as when sprinting. These findings have been constant across numerous types of stretching programs and exercises.
The most controversial findings though, relate to stretching as a means of preventing injury. While some early studies seemed to show that stretching could prevent injury, more recent ones have shown no such benefit. As a result, this question remains unanswered and hotly debated.
While stretching need not be removed from an athlete’s regular routine, it should be done with an understanding of the true benefits and limitations. Certainly, it would appear that stretching should not be as much of a focus as it often is for many coaches and athletes. Rather, if it is to be part of a routine, stretching should be done not as a means of improving performance by preventing injury or DOMS, but rather only for benefiting flexibility. For those athletes who value this benefit, stretching should be done separately from their regular workouts and not as part of a warm-up. Light aerobic activity, known as an active warm-up, has been shown to be better than stretching with respect to improving performance.
Unfortunately, despite the evidence, many will continue to advocate stretching as part of a regular training routine as a means of improving performance or preventing injury. This is not surprising, as the beliefs in the benefits of stretching have become pervasive for far longer than the existence of good evidence contradicting them.
Train hard, train healthy.