You'll see them at every 5K charity race: eager exercisers lunging and quad stretching, hoping to "loosen up." Too bad so few of them know that stretching before the run is probably the last thing they should do.
It may sound counter to everything your gym teacher or soccer coach told you, but stretching your muscles and holding them before you run (or hit the ice, the slopes, or the golf course) not only risks injury; it might actually slow you down.
Traditional stretches, like "the flamingo," the quad stretch of standing on one leg and pulling back the other, are what fitness experts call "static" stretches. While almost all of us have done them ahead of exercising, recent research suggests such stretching before a workout can actually cause your muscles to tighten rather than relax -- exactly the opposite of what you want.
What's more, pulling and holding your muscles before you exercise causes little "micro-tears" that damage the muscle and can lead to injury.
So why is it that so many of us still believe that a workout should start with some long stretches?
Dr. Grant Lum, a Toronto-based sports medicine physician, blames gym teachers -- at least the old-school teachers of our youth.
"Not to slag gym teachers, but 25 years ago, they weren't getting the training they probably do now," he says.
Lum says fitness experts stopped recommending pre-workout static stretching years ago, because a decade or more of research has shown that it doesn't aid performance and may even inhibit it. Yet the stretching myth persists.
"It's like a meme, a concept that pervades society," he says with a laugh. "People believe these things and it just gets reinforced over and over again in lots of contexts."
Lum points to TV broadcasts of Olympic sprinters, who are sometimes shown stretching and bouncing ahead of a race. "So you think, ‘Look, that's an Olympian doing a passive stretch. That must be good.' But you missed the hour of prep that happened before that," he says.
Stretching your muscles when they're cold is a recipe for disaster, say Lum and other fitness experts, such as Nic Martin, the fitness manager at Toronto's Union Station GoodLife fitness club, and Jennifer Wilson, the director of personal training at GoodLife. A better idea is what's called "dynamic stretching." That means slow, even movements that are similar to the moves in your sport.
"It's about mimicking the movement you're about to perform," Wilson says. "You just want to take your muscles, unweighted, through the range of movement that you plan to perform. You're not holding the position; you're just getting your body moving."
So runners, for example, can do a dynamic warmup by simply walking for five to 10 minutes. Tennis players would rally a few balls over the net. Skiers might do a few squats.
"Doing the movement at a slower pace to allow blood to flow into the muscle, that is good preparation. Static stretching is not," Lum says.
In the last few years, several studies have been done on stretching, and a consensus is emerging: static stretching before exercise can actually make you slower.
One study published in the Journal of Strength and Conditioning Research looked at 10 experienced runners, who were asked to run for an hour on a treadmill. In one session, they did some static stretches for 16 minutes before the run and the other time, they didn't.
The volunteers were told to run at an easy pace for 30 minutes and then as far as possible at a performance pace for 30 minutes. But they couldn't see how far or how fast they were running.
Without stretching, the runners averaged 6 kilometres in the half-hour performance run; with stretching, they averaged only 5.8 km, a difference of 3.4 per cent. While that may not sound like much, that could mean the difference between winning a medal and going home empty-handed.
The researchers also found that stretching led to a higher number of calories burned. While that might sound good if you're trying to lose weight, it actually means that the muscles were working less efficiently, having to burn more fuel to keep up the pace. Over a long haul like a marathon, that can mean the difference between finishing and not.
As for the idea that stretching before a workout can help prevent injuries? Or the belief that stretching prevents muscle soreness the nest day? Chalk those up to yet more exercise urban myths.
Experts at the U.S. Centers for Disease Control and Prevention who combed through more than 100 studies on static stretching found that people who stretched before exercise were no less likely to suffer injuries, such as a pulled muscle, than others.
And a systematic review from experts at the well-regarded Cochrane Library, that looked at how stretching before or after exercise affected muscle soreness, found consistent findings: "They showed there was minimal or no effect on the muscle soreness experienced between half a day and three days after the physical activity," the authors concluded.
Despite static stretching's new-found bad reputation, there is still a place for stretching, particularly if you want to become more flexible. And that place is after your workout.
"You can enhance your flexibility by stretching after your workout, when your muscles are nice and warm; that's useful," say Lum.
