Should I stretch before my workout?

An ever-growing pile of evidence suggests that stretching before exercise doesn't improve athletic performance or reduce injuries, and may actually do the opposite, Dr. Bracko says.

But most players are hesitant to tinker with time-honoured routines.

To be fair, there is some ambiguity in the scientific literature.

A major review by the U.S. Centers for Disease Control and Prevention in 2004 concluded there was no evidence to suggest that stretching is beneficial, but not enough to say that it's harmful, either.

Still, a consensus is slowly emerging, Dr. Bracko says, pointing out that:

-- Stretching before exercise will not reduce your risk of injuring yourself during that session, and it will not help your performance. In fact, it's clear that it will temporarily decrease power, speed and running efficiency.

-- Stretching after exercise will not reduce soreness the next day. Any muscle damage has already been done.

-- But regular stretching does seem to produce increased strength and fewer injuries over all. It doesn't seem to matter when you stretch, as long as it's not immediately before your workout.

For many athletes, the question is whether this research translates from the laboratory to the real world. Scientists and coaches at Louisiana State University tackled that issue in a recent study of the school's NCAA-champion track team. The finding: Team members randomly assigned to include stretching as part of their warm-up suffered a 3-per-cent decline in sprinting speed.

So what should you do? Jason Winchester, lead author of the LSU study, recommends a “dynamic warm-up.” Start with a low-intensity, rhythmic activity to elevate your heart rate and body temperature, such as jogging, swimming or easy biking.

Then progress to dynamic movements that mimic the motions of your intended activity. For runners, that might include high-knee drills and butt kicks; for basketball players, some arm windmills; and for weightlifters, lifting with a greatly reduced weight.

Next, add in light stretching either after your workout or on your off-days, says Mr. Winchester, whose consulting clients include NFL teams and the U.S. national track team.

Is there any place for pre-game stretching? Sure, if it really makes you feel good, Dr. Bracko says. Just make sure you warm up first – and continue warming up afterward, to shake out the performance-dampening effects.