In 2010, researchers at Florida State University asked ten male athletes to stretch for 16 minutes, then run for an hour on a treadmill. In a later session, the same crew sat quietly for 16 minutes, then hit the treadmill for the same duration. Without the pre-run stretch, the men covered more distance while expending less energy. The researchers’ blunt conclusion: “Static stretching should be avoided before endurance events.”
Still, the pregame ritual endures. Most of us were taught by our third-grade PE teacher that we need static stretches—like touching your toes and holding for 30 seconds—to be fast and flexible. Most physiologists now believe that when you elongate muscle fibers, you cause a “neuromuscular inhibitory response,” says Malachy McHugh, director of research for the Nicholas Institute of Sports Medicine and Athletic Trauma at Lenox Hill Hospital in New York City and an expert on flexibility. By triggering this protective counter-response in the nervous system, which tightens the muscle to prevent it from overstretching, you render yourself less powerful. In experiments, static stretching temporarily decreased strength in the stretched muscle by as much as 30 percent, an effect that can last up to half an hour.
But stretching prevents injuries, right? Actually, in several large-scale studies of athletes and military recruits, static stretching did not reduce the incidence of common overuse injuries such as Achilles tendinopathy and knee pain.
Get over it: The jury is still out on the best pre-workout alternative, but dynamic stretching, which incorporates a range of body movements rather than muscle isolation, doesn’t stress tissues to the point of activating the nervous system’s protective instincts. If you’re a diehard stretcher, use this five-minute dynamic-stretching routine to warm you up for the race:
1. Jumping jacks (set of 20)
2. Skipping, forward and backward (one minute)
3. High-leg marches: walk forward, kicking each leg up in front of you with knees locked, like a tin soldier (one minute)
4. Kick your own butt: hop on one leg, kicking the other leg backward, touching your buttocks (set of ten per leg)