Is Stretching All It’s Cracked Up to Be?

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Is Stretching All It's Cracked Up to Be?

http://www.nytimes.com/2008/08/07/health/nutrition/07Best.html?

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INVESTIGATORS have begun two large studies of stretching, asking

about its effectiveness in much the way scientists might ask about a

new drug or medical device. They're actively recruiting thousands of

volunteers to participate, in the United States and elsewhere, and

randomly assigning participants to use the method, or not. That is

the only way, researchers say, to detect the subtle effects that most

treatments and exercise interventions might be expected to evoke.

The studies are being done independently, one by researchers based in

Norway and Australia and the other by a group in the United States.

The studies are not identical, reflecting perhaps the different views

of stretching worldwide. People in Norway and Australia stretch for

different reasons than people in the United States and do slightly

different stretches. Yet exercisers and coaches everywhere, the

researchers report, tend to have passionate convictions about the

merits of stretching, or lack thereof.

Researchers say those strong feelings pro and con show in themselves

that it will take a large study to see what, if anything, stretching

really accomplishes. If stretching were remarkably effective,

athletes would notice its effects right away and everyone would agree

on when to stretch and what stretching does.

The study in Norway was the inspiration of Dr. Andy Oxman, a senior

scientist at the Norwegian Knowledge Center for the Health Services.

He had just completed what he calls a public clinical trial. It was a

sort of reality show on public television that asked whether the

nutritional supplement Valerian helped with insomnia; 405 people

signed up to receive Valerian or a placebo and reported on their

sleep by logging onto a Web site. Some participants insisted that

because they slept so well they were taking Valerian. Or they said

they knew they had taken the placebo because their sleep didn't

improve.

Then, the results were announced on the TV show and published:

Valerian had little or no effect on sleep. Some who maintained they

had the supplement actually had the placebo and vice versa.

After that, Dr. Oxman and his colleagues cast about for another good

subject for a public clinical trial. A colleague in Australia

suggested stretching, pointing out that there were no good data on

its effects. The studies that were done were almost always small and

inadequate.

The first question, though, was what is stretching supposed to help

with? Dr. Oxman's group surveyed people in Norway and Australia and

heard that they tended to stretch to prevent soreness and injuries

and enhance well being and performance. In Norway, people stretched

after they exercised; in Australia, they stretched before exercise.

The investigators designed a 13-week study that would include

walkers, runners, cyclists, swimmers and soccer players. That way,

said Gro Jamtvedt, the principal investigator and a researcher at the

Norwegian Knowledge Center, their findings will not be specific to

any one sport — they should apply across the board.

And they decided that to get meaningful results they needed at least

2,300 volunteers who exercised at least once a week and were willing

to be randomly assigned to stretch or not.

Participants enroll on the Internet and report back once a week on

the study's Web site, telling about muscle soreness, injuries and

feelings of looseness. Those who are randomized to stretch are asked

to do a 10-minute program before and after exercise, stretching

muscles in their legs, hips and back. Those randomly assigned not to

stretch must continue their normal exercise routine but refrain from

stretching for 13 weeks. (http://stretchingstudy.nokc.no/study-

stretching-web/innhold/welcome.faces)

Subjects include Luciana Macedo, 28, a physiotherapist in Sydney. She

plays soccer once a week for an hour and a half and was assigned to

the stretching group. She believes stretching helps her loosen

up. " It's almost like if after a stretch you were able to do a bit

more, " she wrote in an e-mail message.

Another participant is Christian Rafn, 59, a management consultant in

Oslo. He plays tennis once or twice a week and occasionally rides a

mountain bike. He thinks stretching prevents soreness. In the study,

though, he was assigned to the group that does not stretch.

So far, the investigators have more than 1,700 participants and are

looking for more — there is no limit to the number they can accept,

Ms. Jamtvedt said.

The stateside study is sponsored by USA Track & Field, but is the

inspiration of Alan Roth, a 65-year-old runner, who is a marketing

consultant and a partner at a start-up company, and his orthopedist,

Dr. Pereles of Montgomery Orthopedics in Kensington, Md.

Dr. Pereles, a marathoner, a triathlete and a member of an advisory

board for Runner's World magazine, mentioned to Mr. Roth that he

wanted to do a clinical trial of stretching but didn't know where to

find enough subjects.

Mr. Roth was intrigued and conferred with the track and field

association. The group agreed to cooperate and Mr. Roth also enlisted

the Road Runners Club of America. He found a statistician in his

local running club and, he said, he got help from the Centers for

Disease Control and Prevention in designing questions for

participants.

THE study (http://www.usatf.org/stretchStudy/) began last August. It

continues to recruit people who run at least 10 miles a week. It is

not asking about soreness — that's not why people in the United

States stretch, Mr. Roth said. Instead, it is asking whether

stretching before exercise affects the injury rate.

Participants are given a static stretching program for their

hamstrings, quadriceps and calf muscles, the sort of routine done by

most runners who stretch, Mr. Roth said. Participants agree to do the

stretches before running, or to abstain from stretching before their

runs, for three months. They also have to report their injuries

during that time. So far, the study has enrolled 1,905 runners of

whom 795 have completed their assigned regimens and submitted

reports.

The researchers will keep recruiting participants until they see at

least a 5 percent difference in injury rates between the stretchers

and nonstretchers or until it becomes clear, because they have

accumulated data from so many thousands of runners, that there is no

difference.

In the meantime Mr. Roth, at least, still stretches the way he always

has: never before exercise, nor afterward. Instead, he stops and

stretches during runs and " at odd times during the day, " he said.

Nevertheless, he said he was agnostic about stretching and was

looking for runners who feel the same way.

" If you listen to coaches or trainers, they are very opinionated

about stretching, " Mr. Roth said. " Some say, `Don't ever stretch

before you run.' Others say, `You just have to stretch before you

run.' We say, if you feel strongly that you must stretch or you must

not stretch, don't join the study. "