There’s an ongoing debate in fitness in recent years about whether you should stretch before or after exercise. It’s a conversation with surprising historical context. Regimented stretching routines were recorded in Greek and Roman times and of course, yoga, with its stretching and elongating postures, traces back 2,000 to 5,000 years — depending upon whom you ask. And until a few years ago, stretching was a stock component of almost all training routines, because it seemed logical: if you stretched muscle fibers and tendons, it would make them more pliable and less likely to tear during intense activity, as well as make you more flexible.
There was little hard science behind the assumption. And of course, it’s more complicated than that. Much of the research done has focused on static stretching, in which you extend a part of the body, such as arms or legs, and hold the stretch for anywhere from 15 to 60 seconds. Several studies in the last 15 years failed to find significant benefits from static stretching, specifically in relation to claims of injury prevention, performance enhancement, and reduction of soreness. In fact, several studies found that stretching reduced performance — especially if that performance was related to strength/power sports, which some claim need “stiff” muscles in order to generate more force during a rapid, eccentric (loading) phase.
The research wasn’t as conclusive on dynamic stretching, in which you stretch a muscle group through a particular range of motion that emulates the movement expected in a sport or training. But for static stretching at least, it seemed the myth had been busted. Until late last year, scientific consensus was increasingly that static stretching was a waste of time.
REHABILITATING STATIC STRETCHING’S STATUS
Now, recent research says there actually may be a place for static stretching. Four exercise scientists, from Canada, Australia, the U.K. and the U.S., reviewed 200 studies of stretching’s effects on subsequent exercise performance. They found that while it could inhibit the generation of power (up to a 4.6 percent drop), this happened only if you held the stretching pose too long (over 60 seconds) and then immediately became active.
The research, published in the journal Applied Physiology, Nutrition and Metabolism, found that most people don’t stretch longer than 60 seconds and often continue to warm up for several minutes after stretching. As a result, the static stretches had insignificant negative impact on subsequent performance. But even better, there was some evidence, based on limited data, that those who performed static stretches for at least five minutes suffered less muscle injury afterwards.
Questioning previous studies that had been critical of pre-exercise static stretching, Dr. David Behm, Memorial University of Newfoundland and lead author of the study, said, “It is important for fitness professionals and enthusiasts, coaches, rehabilitation professionals, and other scientists to critically assess the findings of fitness studies. Many studies over the last 15 years did not include a full warm-up, something that most athletes do regularly. Many studies also tested stretches that were held much longer than what is typically done.
“Before incorporating new findings into your fitness activities, think about how the study applies to your situation and activities,” Dr. Behm said.
Some exercise scientists aren’t convinced this latest research rehabilitates static stretching, particularly for athletes in power sports.
Professor Rob Herbert, now Senior Principal Research Fellow at Neuroscience Research Australia, was the author of a study published in the British Medical Journal in 2002, which prompted a wave of questions about stretching. Prof. Herbert says, “What we do know is that one of the consequences of stretching is that it seems to reduce the capacity of muscles to produce high force and power. So if somebody’s doing a sport that requires very powerful movements, it’s probably silly to stretch those muscles that are going to be doing the work.”
THE CONSENSUS ON STRETCHING
While we still haven’t reached universal agreement on the benefits of static stretching, and there still are fitness experts who passionately believe in it and others that don’t, most exercise scientists believe there is some value in it, depending on the need. Prof. Herbert said, “The best we can put together from well-conducted, randomized studies at the moment is that if there are benefits from stretching, they’re mixed. They’re likely to be for some people but not for all, and the effects are likely to be small.”
SO WHAT DOES EVERYONE AGREE ON ABOUT STRETCHING?
1 STRETCHING IS BENEFICIAL FOR SOME ACTIVITIES, NOT OTHERS — get specific
The experts agree that the issue is healthy connective tissue that is ready and willing to adapt to the physiological task at hand. This is specific to the individual, and may be a matter of hydration, mobility, rest, pH balance and other factors. If you’re in a high-flexibility sport, then you have to stretch to ensure the necessary range of movement. Say you’re a rower, and need to get your body over your hips to get the length of the stroke: you definitely need to stretch. But if you’re in a sport which doesn’t have a high flexibility requirement, then your time is probably best spent doing more productive things in your warm-up.
2 STRETCHING MAY REDUCE MUSCLE SORENESS
Prof. Herbert says there is some evidence that static stretching after activity may result in minor reductions in muscle soreness, but the effect is tiny and doesn’t last long, when tested scientifically. Still, he says, if this tiny improvement is accompanied up by a much bigger placebo effect, in which the person doing the stretching is convinced it’s relieving the pain and it’s beneficial, then stretching is probably worthwhile. Furthermore, stretching helps to restore circulation, energize blood flow and in general, is helpful as a regulator for the range of motion (ROM) of the joint(s) involved and the extensibility of the tissue. If tissue is tight, it can restrict joint ROM; if a joint is misaligned, it can limit tissue extensibility, which can lead to other muscle imbalances and muscle soreness from faulty posture.
3 STRETCHING CAN BE POSITIVE, MENTALLY
If stretching makes you feel good, do it, says the experts. There is growing research exploring the intricate relationship of mindset and physiological performance, as well as the impact on our telomeres (which keep the ends of chromosomes from fraying and degenerating). Therefore, if stretching — dynamic or static — is serving you, go for it. But test and experiment with which type and how long you’re stretching. Try to be strategic and scientific about which movement patterns should be addressed. If it helps you relax or rev up before an activity, do it. If stretching relieves the sensation of tightness in your muscles before or after an activity, do it. In all, stretch if you think it makes you feel better — it likely does.