Outside magazine, May 1996
You'll rarely, if ever, hear anyone question the wisdom of a good warm-up or deny the importance of flexibility. But shout "Stretch!" in a crowded trainers' convention and you're liable to start a brawl. "The medical literature doesn't support the idea that stretching prevents injuries," says Sam Yanuck, an applied kinesiologist and cofounder of the Foundation for Allied Conservative Therapies Research, which funds studies of alternative health care. "It supports the idea that stretching increases injuries."
Yanuck's view--which is hardly in the mainstream--can be boiled down thus: flexibility, yes; stretching, maybe. If your sport requires extreme flexibility--gymnastics, track and field, aerial skiing--then go ahead, he says, with caution. If you're an endurance athlete, though, warming up and cooling down properly will give you all the flexibility you need. "One of the ways to screw up the mechanics of a joint is to stretch the muscles that cross it," Yanuck says. "If you stretch them slowly, you'll increase the resting tone of the muscle; if you stretch them abruptly, you'll decrease the tone. Unless you have remarkable skill at knowing the neurology of your muscles, it's going to be a dice roll. What's much better is to warm up in a slow and gradual cardiovascular way." A good ten- to 15-minute easy effort in your sport, he says, should do the trick.
Likewise, according to Yanuck and his compatriots, cooling down after a workout is more important than stretching. "You can't just stop on a dime," he says. "You're asking for a sudden heart attack that way." But he concedes that if you insist on stretching, now's the time to do it. "If you're going to stretch, it's better after a workout, because your blood is moving through your muscles and can respond better to stretching." To which he adds this plea: "Be sure to stretch from the bottom up-from feet to head-and do it slowly!"