Notes on Stretching-Flexibility

We stretch to lengthen out tight muscles, enhance performance and repair injured tissues. Right? Not necessarily. We’re stretching for all the wrong reasons, science writer Beth Skwarecki says in a new feature. “In many cases, stretching does the opposite of what it’s promoted for,” Skwarecki says. “You already know that it doesn’t prevent injuries. It also doesn’t cure muscle soreness; in fact, aggressive stretching can cause muscle soreness. And pre-workout stretches, far from preparing you to work out, actually rob you of strength.”

It is the opposite of what we’ve been taught about stretching, so what is the truth?

In a series of studies from 2002, Professor Rob Herbert, a researcher fellow with Neuroscience Research Australia, found that stretching reduced the likelihood of soreness by less than 2 per cent and that stretching reduced the likelihood of experiencing a sports injury by about 1 per cent. “Available evidence suggests there’s probably very small reductions in soreness,” Herbert says, noting reduction in injury risk is “trivially small”. “That’s pretty well recognised now,” Physiocise executive director Anna-Louise Bouvier says of stretching’s minimal impact on soreness.

It is the same story with injury, she says. In fact, stretching can actually create injury. “When you’re well warmed up, there’s the tendency to stretch too far,” Bouvier explains. Even without overdoing it, stretching can damage muscle fibres. “You’re just tearing them by stretching them instead of by contracting them,” Skwarecki says. “If you want to stop feeling sore, aggressive stretching is the last thing you’d want to do. “Because muscle pulls [strains] feel similar to soreness, people often have the same reaction, wanting to stretch the pulled muscle. Here it’s an even worse idea: the pulled muscle needs to knit back together, and stretching sabotages that process.”

Interestingly, the tearing involved in stretching can make us stronger in the long term. “If weightlifting and stretching can both cause muscle damage, they should both cause the muscles to repair themselves stronger than they started,” Skwarecki explains. “Stretching does cause hypertrophy – muscle growth – and this seems to explain why people who stretch end up stronger over time.”

In the short term however, stretching decreases our strength. “Imagine a catapult,” Bouvier says. “When the arc is shorter you’re going to be able to generate more force.” When it’s stretched out though, the “arc” lacks force. For this reason, stretching can hinder our performance say, if we do it right before we lift weights or need to perform an activity requiring explosive power. “It’s the most complicated,” Herbert says. “It hasn’t been rigorously tested. It may improve performance in some things and it definitely does decrease performance in certain things.”

But, perhaps the most surprising truth about stretching is that it doesn’t lengthen our muscles. At least, the effect doesn’t last in the short term, Bouvier says. If we stretch for years, however, and also build strength to support our newly elongated muscles, it might be a different story. Hello yoga, pilates and ballet. But, if stretching isn’t doing the things we think, what exactly is the point? Herbert points out one limitation of many stretching studies to date. “All these studies have looked at five months,” he says, “not five years.” He doesn’t stretch himself and hasn’t stretched before sport for 20 years, since he started his research into the subject. His take on stretching is: “If it feels nice, do it.” And for many of us, the fact that stretching feels so good is point enough. “It can relieve a lot of muscle spasms and as a short-term relief can feel beautiful,” Bouvier says, noting that flexible “floppy” folk do it intuitively.

For those who find stretching tough, “stiffys” as she calls them, it’s all the more reason to do it. “The body needs stretching and strengthening,” she says. “Stiffys hate stretching but should do quite a lot of it. Floppys need to work more on strength. This, she adds, is an oversight, too often missed in studies: Not all bodies and not all muscles are the same. “They say ‘this applies to all bodies’ but we should say ‘this applies to some bodies’,” Bouvier says. “Basically what you hate is often what you really need.”

While stretching may or may not lengthen muscles in the long term, perhaps it returns them to their original supple state, after years of contraction and sitting stiffly at desks? “Maybe not their original supple state,” Bouvier says, “more like putting a bit of leather rejuvenator on an old handbag … softens them!” Another possible point is the positive effect stretching has on fascia, the connective tissue that surrounds our muscles.

Few studies have been done, but it’s a promising area of research. “It is full of nerve receptors and while we don’t totally understand how it is involved it’s definitely the next horizon in ‘releasing’ tension,” Bouvier says. “Fascia is especially important if the muscle has spasmed due to pain or protection. “Certain specific stretches especially ‘bigger’ stretches are great for releasing fascial chains and also feel fantastic but the long-term ramifications and underlying reasons for that are still not 100 per cent clear.”

We might be stretching for the wrong reasons, but that doesn’t mean there aren’t still excellent reasons to stretch it out.