Stretching the Limits
Certain Stretches Can Decrease Power Output
Contrary to popular wisdom, certain stretches might actually reduce athletic performance.
A UNLV study investigated how two typical stretching techniques for the hamstring and quadricep muscles affected measures of leg strength and power in a group of male and female athletes.
While the decrease in power may not warrant a change in warm-up routine for recreational athletes, it is significant for competitive athletes participating in activities requiring maximum power, such as football and track and field.
Stretching Reduces Power
Participants performed a vertical jump and seated knee flex on three occasions after typical static (holding) and ballistic (bouncing) stretches, or no stretching at all. While little or no difference was found in vertical jump and leg torque, power measures for the stretching groups were significantly reduced.
"Athletes typically include static stretching as a part of the warm up, but the evidence is clear that this practice will decrease performance in sports that require explosive movements," said kinesiology professor and study co-author Bill Holcomb, who directs the Sports Injury Research Center at UNLV. "Developing flexibility is important for reducing sports injury, but the time to stretch is after, not before, performance."
Whole-Body Warm Up
Holcomb suggests that coaches limit warm-up stretching in most sports and refrain from pre-activity stretching altogether for sports that require maximum power. Instead, athletes should perform a whole-body warm-up activity followed by sport-specific stretching.
Because it requires a person to generate force at rapid speed, the vertical jump is used in research as a predictor of power. Also, the hamstrings and quadriceps both function as major muscles used in jumping.
Participating with Holcomb in the study, which appeared in the September 2008 issue of the Journal of Strength and Conditioning Research, were department of kinesiology and nutrition professors Mack Rubley and Mark Guadagnoli and graduate kinesiology student Michelle Samuel.
Related Information
Bill Holcomb
Department of Kinesiology and Nutrition Sciences
Journal of Strength and Conditioning Research
Medical News Today
