Stretching After or Between Exercise -- Not Before -- Cuts Injury Risk
These surprising conclusions come from a systematic review of all published studies of stretching by Ian Shrier, MD, PhD. Shrier is past president of the Canadian Academy of Sport Medicine and a researcher at SMBD-Jewish General Hospital in Montreal, Quebec, Canada.
"If strength or power is important to you, don't stretch before exercise. If you enjoy stretching, stretch after exercise, or at other times," Shrier tells WebMD in an email interview. "There are certain exceptions to these rules where performance depends only partly on force and power, and partly on aesthetics and range of motion -- a good example is ballet."
Shrier examined 23 articles on "acute stretching" -- stretching just before exercise. He found that:
- 22 of the 23 reports showed no benefit in terms of force, torque, or jumping height.
- One study showed that stretching before exercise made for more efficient running.
- Of the four articles that looked at running speed, one showed that stretching before exercise was helpful, one found it slowed runners, and two had "equivocal" results.
Shrier examined nine articles on regular stretching -- either after exercise or at some other time. He found that:
- 7 of the 9 reports showed a benefit.
- The two reports showing no benefit looked only at running economy.
- None of the reports found any harm in regular stretching.
"An acute bout of stretching will decrease pain temporarily but will not prevent injury," Shrier says. "Stretching over weeks to months will increase your force, power, and speed of running, and may prevent injury. Both an acute bout of stretching and regular stretching over weeks to months will increase range of motion."
Many Still Recommend Before-Exercise Stretching
Despite these studies, Shrier notes that many fitness experts still advise stretching before exercise. One of them is certified athletic trainer and physical therapist Michele Raya, PhD, assistant professor of physical therapy at the University of Miami in Coral Gables, Fla.
"In my opinion I do think it prevents injury. The benefits are pretty clear," Raya tells WebMD. "I do recommend to the athletes I am working with to stretch before activity. And I work with athletes at the high school, college, and professional level in running and jumping sports."