Stretching Is Not a Good Way to Prevent Injury, Research Shows
By: Christie Aschwanden
Tags: Stretching, Exercise, Body, Test Gym, Fitness

I Quit Stretching and So Can You

The case against stretching has science on its side

I was a devoted stretcher for years. My high school track team began every practice with a ritualized routine of stretches, and all through my college running career, I would never begin a run without bending down to stretch my hamstrings. Until eventually I started looking into the scientifically verified benefits of stretching, and I was shocked to discover that I couldn’t find any. Sure, stretching can improve your flexibility — practice touching your toes enough, and you’ll increase your reach — but beyond that, the confirmed advantages to stretching are non-existent. There are even a few hints that stretching could be detrimental to athletic performance in some circumstances. After seeing this spelled out in so many scientific studies, I quit stretching cold turkey, and I’ve experienced no discernible harms.

My indoctrination into stretching is pretty typical. I stretched, because it was what runners did. Stretching was supposed to make me less sore and prevent injury. I also thought it loosened up my muscles, never mind that my hamstrings have been tight every day of my life, stretching or not. But it’s the notion that stretching could protect me from injury that was the most compelling to me. “I don’t know where it came from, but the idea that stretching is necessary to prevent injury has a long history,” says Adam Meakins, a sports physiotherapist and strength and conditioning specialist in Hertfordshire, England. “There’s a lot of fear around it,” he says, propagated by health care providers and the media touting stretching’s powers to prevent injury, despite evidence to the contrary. Even so, stretching has become a hallowed part of sports tradition. A 2016 survey of more than 600 personal trainers in the U.S. found that a staggering 80% of them included stretching in their exercise programs.

Before you stretch, ask yourself: What’s your goal?

Despite such popularity, researchers have failed to confirm the purported benefits of stretching. But before we get into the science, a few definitions. Stretching has an almost endless array of variations, but for our purposes here, stretching means “static” stretching — lengthening or pulling a muscle group until it’s as extended as possible and then holding. The classic example of static stretching is touching your toes. Sometimes it’s done before working out, sometimes it’s done after, but the consequences are generally the same.

Despite beliefs to the contrary, research has shown that stretching isn’t a good way to prevent injuries.

If your goal is to increase your range of motion (what we think of as “flexibility”) then by all means, go ahead and do some static stretching, says Gary Liguori, PhD, dean of the College of Health Sciences at the University of Rhode Island and a fellow of the American College of Sports Medicine. Static stretching can help your flexibility (for whatever that’s worth), but he says, even if it has “little or no impact on performance, overall health or injury prevention.”

Stretching doesn’t prevent injury or soreness

Despite beliefs to the contrary, research has shown that stretching isn’t a good way to prevent injuries, Meakins says. Multiple studies have found that stretching doesn’t meaningfully reduce injuries. For instance, a 2005 analysis of studies on army recruits undergoing basic training concluded that static stretching did “not meaningfully reduce lower extremity injury risk of army recruits undergoing military training.”

Another common reason given for stretching is that it might reduce muscle soreness. But a Cochrane review published in 2012 analyzed data on stretching from 12 studies with a total of more than 2,300 participants and concluded that “muscle stretching, whether conducted before, after, or before and after exercise, does not produce clinically important reductions in delayed-onset muscle soreness in healthy adults.”

Unless you’re doing an activity like gymnastics or ballet that requires specific types of flexibility (like doing the splits) stretching probably won’t enhance your performance either. Studies have shown that flexibility in the hamstrings, as measured by a sit and reach test, is associated with less efficiency and economy for runners. A 2014 study even found that static stretching decreased performance in a one-mile time trial by trained male runners.

“Stretches held for a long period of time might decrease muscle power output,” Liguori says, but that probably doesn’t matter if you aren’t doing activities that require high muscle power output, such as sprinting or powerlifting. Whatever performance detriments stretching has, they are admittedly pretty small and probably don’t matter for most exercisers, but stretching isn’t really improving performance either. Stretching is often done as a warmup, but it’s not the only or even the best way to ease into a workout. Warming up with things like bounding and high knee kicks can be a good way to increase your range of motion, says Liguori, who admits he hasn’t done any static stretching in a long time.

Another strategy to stay flexible: strength training

Even if you’re aiming to improve your flexibility for its own sake, stretching isn’t the only or even necessarily the best way to do it. It might seem counterintuitive, but strength training is another good way to increase range of motion and make yourself more flexible, Meakins says. When you do a strength exercise like a squat through a full range of motion, you’re pushing your muscles to contract and stretch through that full scope of movement. There’s a common assumption that the stronger you get, the stiffer your muscles will be, but that’s not necessarily the case, Meakins says. Instead, it depends on the types of exercises you do. Eccentric exercises — think lowering a barbell or lowering your leg during a leg curl — actually elongate the muscles and can increase flexibility.

But the benefits of flexibility and stretching do not live up to their reputation. A recent paper in the journal Sports Medicine from exercise scientist James Nuzzo, PhD, of Neuroscience Research Australia argues that given the paucity of benefits, it’s time to retire flexibility as a major component of physical fitness and de-emphasize stretching as a standard component of exercise prescriptions for most people. The Institute of Medicine is already on board, Nuzzo writes. “In 2012, the Institute of Medicine recommended tests of flexibility not be included in youth fitness testing because of a ‘lack of evidence for an association between flexibility tests and health outcomes.’”

“Stretches held for a long period of time might decrease muscle power output.”

If I haven’t convinced you yet that you can quit stretching, I’m not surprised. The three pages I wrote about stretching in my book, Good to Go: What the Athlete in All of Us Can Learn from the Strange Science of Recovery, garnered more backlash than anything else I debunked in the book. On a live NPR show, a circus performer called in to tell me that the “multiple hours a day” his performance team spends stretching is the reason they’re “not seeing any injuries.” To say that stretching “doesn’t do anything is just not true. I’ve seen it firsthand,” the caller insisted.

What could I say? It’s very hard to argue against personal anecdotes, and, as I told him, I couldn’t vouch for his experience. All I can say is that when researchers have tried to confirm that stretching prevents injuries they’ve come up empty-handed.

Still, I understand why stretching has so many devoted fans, and I’m open to the idea that it might feel worthwhile for some people. As I write in my book, stretching is “an excellent placebo, because it’s ritualized, it provides a sense of agency, and it feels like something’s happening, which can reinforce an expectation that it’s working.”

Placebos can be found all throughout sports and medicine, so in that sense stretching isn’t so unusual. “In fairness, we have a lot of ritualistic things people do for their health in America that have far less evidence than stretching,” Liguori says. And there are probably non-scientific reasons for stretching that shouldn’t be dismissed. “There are some stretching addicts out there who just enjoy the sensation of the pulling,” Meakins says. Some people might even find stretching meditative or a way to relax after or even before a workout. (Personally, I prefer warming up and cooling down with some light exercise, like walking for a few minutes before and after my run.)

If that’s you, then fine. Go ahead and keep stretching. I’m not going to stop you. But I might be a couple miles down the trail before you start your run.