Photo Credit: Tobyotter on Flickr

by Khaled Allen

When I was running cross country in high school, we always began each practice session by stretching to avoid injury, and after we were done, we’d stretch again. We did this presumably to prevent injury, but despite the fact that I was the most flexible person on the team, I was injured most of my senior year. Nevertheless, I continued to stretch because I felt knotted and stiff when I didn’t.

A few years later, a number of studies came out suggesting that stretching wasn’t helpful to distance runners at all. According to some researchers, distance runners actually don’t need to be flexible. Some cite studies that prove stretching doesn’t prevent injury, and may actually make it more likely. Some say stretch only if you need to get more flexible.

The points against stretching are pretty harsh. According to a study published on the Gatorade Sports Science Institute website, stretching before exercise may cause temporary strength deficits, doesn’t prevent injury, and doesn’t improve exercise performance. The study did find that passive stretching, done away from the exercise environment, may improve flexibility, but the study also claimed that increased flexibility was detrimental to runners.

Surprisingly, a number of studies do actually find that less flexible runners, both low level and elite, are more efficient than more flexible runners. How can that be, you ask? Where does the belief that runners don’t need to be flexible come from? A lot of these studies actually make the claim that no athlete benefits from stretching, which is ridiculous. The vast majority of athletes studied have been distance runners, who have minimal flexibility requirements, and to extrapolate from them to weightlifters, gymnasts, or even track and field is poor science.

But What About the Runners?

Honestly, distance runners need to be flexible too. According to Dr. Nicholas Romanov, the creator of the POSE method of running, CrossFit’s running style of choice, all runners need to be flexible. Dr. Romanov gleefully tears apart the claims of scientists suggesting that reduced flexibility can improve elasticity in the hamstrings and calves by pointing out that these muscles don’t even work the way the scientists suggest they would if they were stiff.

In my opinion, it comes from the fact that most distance runners run in motion-controlled shoes, on smooth asphalt roads, and actively avoid movements that require any real range of motion out of their joints. Distance runners don’t sprint, they don’t jump, and they don’t hurdle obstacles. If you buy into the barefoot running trend, we’ve all been running with incorrect form since we started running with “running shoes,” since heel-striking makes us more prone to injury. If that is true, then it wouldn’t be surprising that less flexibility might be helpful to running with poor form. If you’re going to do things the wrong way, you’re body is going to find a way to protect itself at the expense of other abilities. To get really good at running incorrectly, it would seem that your body sacrifices flexibility.

I believe that trail running is a much more holistic approach to running as a fitness endeavor, and incidentally, trail runners have to do all the things road runners get to avoid. For a road runner, every step is the same, so it doesn’t matter if you can’t alter your stride efficiently. For trail runners, every step is different, and if you are inflexible, you’ll twist an ankle or pull a hammy.

Personally, I think it’s pretty clear that stretching is important to being a good runner.  I don’t think there’s much debate that flexibility is important for navigating the obstacles on the Spartan Race courses either.  Dr. Paul Baird, who helps athletes prepare for the Grand Teton Relay race, cites the story of a client who came to see him with lower back and hamstring pain.  He had run the Boston Marathon and then gotten in an airplane without stretching.  Dr. Baird found the client’s quads and hamstrings were tight as a result of being held in a single position after contracting during the marathon.  What did he prescribe to loosen them up?  Stretching.  After starting this program, the pain went away, and the patients’ performance increased.

Bad Science

But wait, doesn’t the science show that stretching doesn’t help reduce injury in runners? Maybe researchers don’t consider paralyzing back pain an ‘injury,’ but this example suggests that, yes, stretching does help prevent injury in runners. Even this study from the Gatorade Sports Science Institute, which reviewed all the current research on the topic, admits that science doesn’t seem to have all the answers in this case.

So why is it so unclear if stretching is actually beneficial or not? Again, we can blame the methods used in the studies that have been conducted. In the New York Times, Dr. Julie Gilchrist, a medical epidemiologist at the Centers of Disease Control and Prevention and co-author of the latest stretching study performed by the CDCP, points out that all of the studies that conclude that stretching does prevent injuries also included warm-ups with the stretching. Those that concluded that stretching decreased muscular performance and proprioception did the stretching in a lab setting. Basically, the scientists weren’t careful about keeping their variables in order.

“The problem is that what is actually studied in the lab has very little intrinsic links to what is happening” when people actually exercise, said Christopher Morse, an exercise physiologist at Manchester Metropolitan University in England who has published papers on stretching and reviewed the stretching literature.

The claim that flexibility can make runners more efficient seems to have little scientific evidence to back it up, but that doesn’t stop most athletes from stretching regularly. And if Dr. Romanov, the renegade authority on efficient running technique, doesn’t buy the science, I’d be inclined to listen to him.

In fact, even the researchers finding no benefit from stretching do stretch, according to an article in the New York Times. Dr. Gilchrist was wavering at the time of her interview, saying, “I am so inflexible I think it’s hazardous. I am seriously considering stretching,” and two of the other doctors interviewed whose research didn’t support stretching did themselves stretch regularly.

Apparently, nobody believes the science. It is difficult to do studies on stretching because athletes won’t stop stretching to participate in a control group, according to the NYT. Even the scientists finding no benefit will stretch.

There’s More than One Way to Stretch

So what about my old cross country injuries?

It turns out stretching is not the only way to get more flexible, and muscles can be tight for a number of reasons. In my case, I had weak glutes and hips. Weak muscles are held under tension to protect them, resulting in tightness and inflexibility. Once I started doing heavy squats, my hips became much more flexible. Other causes of inflexibility include adhesions and scar tissue, which traditional stretching cannot help with.

Perhaps all the confusion in the scientific literature has to do with failing to make the distinction between causes of inflexibility that lead to injury.

Mobility exercises such as active-release therapy (deep tissue massage that breaks up adhesions) and proprioceptive neuromuscular facilitation (contracting and relaxing a muscle while it is in an extended position) may be more effective at developing neuromuscular control of muscles throughout the range of motion. Since flexibility is related to neural activation and strength in addition to muscle fiber length, dealing with shortcomings in these areas might be what some athletes need to avoid injury, rather than simply stretching the muscles.

So what is the conclusion? I think that runners need to be flexible in order to run most efficiently, based on the beliefs of POSE running and my own experiences with barefoot, minimalist, and trail running. Based on the studies that have been done, it seems that passive stretching is all that is studied. Because passive stretching doesn’t improve neuromuscular activation or strength in the outside range of motion, I am not really surprised it may actually lead to increased risk of injury, as some studies find; you’re basically training the muscle to stay loose when it should be supporting the joint. There are so many ways to stretch muscles, and I think studies need to make a better distinction between the various options.

Universally accepted notions are to stretch when you’re warm and to listen to your body. If it hurts in the wrong way, stop. Play with alternative methods, such as mobility (for some ideas, check out CrossFit’sMobility WOD). Don’t discount the importance of flexibility in navigating a rocky riverbed, scaling a rope, or crawling under a barbed wire. A joint ought to be able to operate powerfully and painlessly throughout its entire range of motion. To leave it otherwise is inviting disaster.

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One Response

  1. avatar

    I have a door gym and incorporate ehnstctirg into my strength training, and I have a little yoga routine, as well. Definitely work on your flexibility now – it doesn’t get easier with age! Although you’re a LONG way from having to worry about it, flexibility is especially important in the second half. Just start slow and work on it daily and you’ll be touching the floor in no time:)

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