Strength training and balance exercises are more likely to help prevent sports injuries than stretching, a new look at the evidence suggests.
Researchers said it's not clear which specific exercises have the best chance of warding off ankle sprains, ligament tears and other injuries.
"If you could do some kind of strength training … that would be our best (recommendation) for now. But we need more studies to confirm these results in order to be totally sure," said Jeppe Lauersen.
He led the review of past studies at the Institute of Sports Medicine Copenhagen at Bispebjerg Hospital in Denmark.
The researchers combined data from studies that randomly assigned people, mostly adult or teenage athletes, to groups that either completed certain exercises or did not. The studies followed participants to see who got injured over a period of a couple of months to a year.
The final analysis included 25 trials and more than 26,000 participants, including soccer, basketball and handball players and army recruits.
Some of the studies tracked all possible injuries. Others had a more specific focus, for example looking only at hamstring injuries or knee injuries related to overuse.
Overall, researchers analyzed close to 3,500 injuries.
Lauersen and his colleagues found three studies that looked at stretching programs and showed no benefit for averting injury.
The limited data "do not support the use of stretching for injury prevention purposes, neither before or after exercise," the study team wrote in the British Journal of Sports Medicine.
But six studies that looked at the effects of balancing exercises meant to improve joint stability found a 45 percent lower risk of injury among people in the exercise group. And strength training exercises to build muscle led to a 68 percent drop in injuries in four studies.
Those benefits seemed to apply to both overuse injuries and more acute sprains and tears.
Still, Lauersen said there is a lack of studies supporting one specific strengthening or balance program over another. So it's hard to know how to advise athletes.
Bing Yu said the way studies were combined in the new review also makes it difficult to take away any specific messages.
"Counting all injuries together, it's very hard to say which (exercises) actually work for which injury," said Yu, from the physical therapy division at the University of North Carolina at Chapel Hill. He did not participate in the current report.
Yu agreed there is little evidence to suggest stretching is helpful. He said for some athletes, improving technique might be the most important injury prevention tool.
"Technique is really important. Very basic techniques, like landing," he told Reuters Health.
And not overdoing it is an important way for recreational athletes like runners to avoid injuries, Yu added.