For generations, athletes of all ages and abilities were taught the gospel of stretching before they exercise to boost performance and prevent injuries.

“Then in the late 1990s and early 2000s, a number of reports indicated that static stretching might impair performance in activities like jumping or weight lifting,” says David Behm, a professor in the School of Human Kinetics and Recreation at Memorial University of Newfoundland in Canada.

(Static stretching is stretching without movement, like when you bend over, reach for your toes, and hold.)

“But there are problems with that research,” says Behm, who literally wrote the book on the topic—The Science and Physiology of Flexibility and Stretching.

For starters, some of the studies weren’t realistic. “In one, they looked at stretching the calf muscles for 13 repetitions of 135 seconds each,” notes Behm. “Who stretches just their calves for 30 minutes?

What about shorter stretches?

“When we looked at 125 different studies, we found impairments of about 3 to 5 percent if a single muscle was stretched for more than a minute,” says Behm.

But that doesn’t mean much for your average weekend warrior.

“Let’s say you usually hit a tennis ball at 100 miles per hour,” says Behm. “If you over-stretch beforehand, you may hit it at 95 mph. What difference does that make to your game? None. A 5 percent impairment may matter for Roger Federer, but it’s trivial for the average person.”

In fact, stretching has a payoff if it’s done right. “If you stretch a muscle for less than 60 seconds, you’re not going to have issues,” says Behm. “And it may decrease the chance of acute injuries like muscle strains without impairing your performance.”

Behm's stretching advice:

  • Warm-up. “Do five minutes or so of aerobic activity like cycling or brisk walking to warm up the body.
  • Static stretching. “Hold each stretch for no more than a minute total.”
  • Dynamic stretching. “You could kick each leg back and forth, do big arm circles, that kind of thing.”
  • Specific movements. “Do a few minutes of the movements specific to the sport, like hitting a tennis ball a few times, before you start your match.”

Sports or no sports, stretching has other benefits, like increasing joint mobility. Think of it as its own activity…one you can do, say, while watching TV.

“Improving your flexibility through stretching can make day-to-day activities easier, especially as we age,” says Behm.

“It’s easier to bend over to pick things up. Or maybe you’re hiking and need a longer stride to go uphill or take a large step to get over a rock. If you don’t have that flexibility, you won’t be able to do it.”

The bottom line

Stretch before you exercise...and whenever you can during the day.

Photos: Lightfield Studios/