So you don’t need to stretch before exercise?

The NY Times reports on a randomized control trial of stretching. The punchline: “static stretching had proved to be a wash in terms of protecting against injury.”

But wait…

But many people remain fiercely attached to their stretching routines. “It was really hard to recruit runners” who, used to stretching, would agree to be randomly assigned to the nonstretching group, said Alan Roth, a former board member of USA Track and Field and coordinator of the study.

Once they understood that they might be required to not stretch for three months, they declined to participate. It took the researchers more than two years to coax enough runners to join and complete the study, generating enough data for meaningful results.

That repetitive knocking sound you hear in the distance is me banging my head against the wall. So the results only apply to people who don’t find they need to stretch? I think we can safely throw generalizability out the window.

Deeper into the article:

One anomalous finding of the USA Track and Field study was that runners who were used to stretching and were assigned to the nonstretching group became injured at a disproportionately high rate.

Yes. An “anomolous” finding indeed. Ah, pesky facts; how you trouble medical science and journalism.

Who knows what the truth is? But if you want to win bets in life, predict the opposite of mediocre research. Five years from now, the headline will read: “Studies show stretching reduces injuries!”

You heard it here first, folks.

8 Responses

  1. Didn’t bother to read the article as much of what’s printed in the MSM about exercise science is either behind the times, misses the forest for the trees, or both. For those who may be interested, a great book for lay people on stretching is Stretch to Win, by Ann and Chris Frederick. They explain, so far as is understand to date, the physiological mechanisms behind soft tissue adaptation to stress and the role of stretching in promoting healthy soft tissues. And then they tell you how to stretch properly.

    Great blog, by the way.

  2. Jason Kerwin said: “We should really be framing the question in the opposite way. Stretching advocates claim it reduces injuries. Where is the actual evidence for this claim? What is the physiological mechanism by which stretching might prevent injuries, and why do we think it works?”

    Well, it’s not as easy as simply to reverse the burden of proof. I’ve also heard sometimes that nowadays the informed opinion is that stretching is supposed to be done after the exercise, otherwise it may actually increase injury. But I didn’t dig deep enough into the subject to the point that I could actually endorse it. I don’t know if there’s strong empirical evidence proving conclusively either case, neither a radical difference in likelihood of mechanisms by which it would prevent or increase the chance of injury. And I guess that, if there is research like this still being made, with mixed results, the question is probably not entirely settled. Perhaps there is individual variation at the histological level making both things true to different persons, I don’t know.

    I don’t see that much trouble with the study or with the NYT piece, if the problem mentioned is all the problem that is there. It would actually be better than average, regarding articles on scientific research.

    Well, one could not force people deeply worried about not stretching to not stretch. Except, perhaps paying quite a lot. And even then, as the text says, isn’t like the study left out those who think they need to stretch, only that refusal to participate was very common. I wonder if nocebo effect played some role on the higher rate of injuries of this group, or whether it’s like some intuition about what’s best for oneself. Perhaps there are people who benefit from stretch and those to whom stretching is actually bad, and people can eventually learn to “feel” their own stretching needs or lack thereof.

  3. My point is not that stretching–dynamic or static–is good or bad or neutral. It seems to me that all of the evidence people are citing is inherently selective, based on high performing athletes or randomized control trials on funny, select samples. Some of these studies may be better done, and I have not read all. I am simply disappointed when scientists and journalists make elementary mistakes over and over again.

  4. This finding comports with the Cochrane review (http://www2.cochrane.org/reviews/en/ab004577.html) of 10 randomized experiments, albeit with soreness, not injury, as the outcome measure: “The evidence derived from mainly laboratory-based studies of stretching indicate that muscle stretching does not reduce delayed-onset muscle soreness in young healthy adults.” There are a few other small RCTs on stretching out there and, AFAIK, none report any significant effects.

  5. That stretching is ineffective at reducing injuries, and may in fact increase them, has been well known for years; my high school track team got rid of stretching shortly after I graduated in 2002. This is simply more evidence in support of something we already knew.

    We should really be framing the question in the opposite way. Stretching advocates claim it reduces injuries. Where is the actual evidence for this claim? What is the physiological mechanism by which stretching might prevent injuries, and why do we think it works?

    Bear jn mind that stretching and warming up are separate activities and the evidence in favor of warming up is much stronger.

  6. Outside of academia I coach speed-power events in track and field. Think sprinting and jumping. Stretching is not the key, mobility is, and they are not the same things. Bottom line is that if you are cold and then try to go hard, you’ll pop. Hang out with high end athletes… it is surprising how little they stretch. What the study doesn’t say is that stretching can increase your range of motion, which in turn increases the range through which you can apply maximum power. A different reason to stretch, and why stretching is often put together as a distinct workout in itself.

  7. Dyanamic warm ups are better for me (and everyone I know who does them) than streches. Dyanimic warm ups get me looser and are quicker than static stretching. Consider trying lighted pliometrics and resistance stretches instead of static streches. You’ll never go back to static.

    That said, this rct had some design issues.