The Right Way to Stretch Before Exercise
For generations, gym students were taught to stretch before working out or playing games. Then the practice fell out of favor: Studies seemed to show that such ‘‘static’’ stretching (holding a pose for anywhere from a few seconds to several minutes) temporarily reduces muscular power, weakens athletic performance and increases the risk of injury. So most fitness experts currently advise against static stretches before exercise. But now a comprehensive new review of decades’ worth of research indicates that they might not be such a bad idea after all.
This month, the journal Applied Physiology, Nutrition and Metabolism published a study by four distinguished exercise scientists who analyzed more than 200 studies of how stretching affects subsequent exercise. (The authors had conducted some of these studies themselves.) In broad terms, they found that static stretching can briefly inhibit the ability to generate power. So if you reach for your toes and hold that position, tautening your hamstrings, you might not then be able to leap as high or start a sprint as forcefully as if you hadn’t stretched.
本月，《应用生理学、营养学及新陈代谢》（Applied Physiology, Nutrition and Metabolism）杂志发表了一项研究，四位著名运动科学家分析了200多项关于拉伸如何影响后续运动的研究。（其中部分研究由四位科学家自己开展。）总体来说，他们发现静态拉伸会暂时抑制身体爆发力。所以如果保持手触脚趾的姿势，拉伸腿筋，结果可能还是不拉伸的情况下跳得更高，或冲刺得更有力。
Those undesirable effects were generally found, however, only if each stretch was held for more than 60 seconds and the subject then immediately became fully active, with no further warm-up. Those are hardly real-world conditions, says Malachy McHugh, the director of research at the Nicholas Institute of Sports Medicine and Athletic Trauma at Lenox Hill Hospital in New York, who is the study’s co-author. Outside the lab, he says, most people are unlikely to hold a warm-up stretch for longer than about 30 seconds. The review found few lingering negative impacts from these short stretches, especially if the volunteers followed that stretching with several minutes of jogging or other basic warm-up movements. In fact, these short static stretches turned out to have a positive correlation. People who stretched in this way for at least five minutes during a warm-up were significantly less likely to strain or tear a muscle subsequently.
然而，这些不良影响基本是在运动员每次拉伸保持60秒以上并且不做进一步的热身马上开始充分运动的情况下才发生。纽约莱诺克斯山医院（Lenox Hill Hospital）尼古拉斯运动医学和运动创伤研究所（Nicholas Institute of Sports Medicine and Athletic Trauma）的研究主任马拉奇·麦克休（Malachy McHugh）是本研究的合作者之一。他说以上的情况几乎不会在现实中发生。他在实验室外说道，大多数人做热身的拉伸运动不太会超过30秒。这项研究发现这些短暂的拉伸运动几乎不会带来挥之不去的消极影响，特别是如果志愿者在拉伸之后再花几分钟慢跑或者做其他基本的热身运动。实际上，这些短暂的静态拉伸反而产生正面影响。在热身的时候这样拉伸五分钟以上会大大降低之后肌肉拉伤或撕裂的可能性。
Do these findings mean that those who happily dropped pre-exercise stretching from their warm-ups should reinstate the practice and overturn, once again, accepted fitness wisdom?
Not necessarily, Dr. McHugh says: ‘‘Runners and cyclists don’t have much risk for acute muscle strains.’’ Stretching before these activities is therefore unlikely to protect against injury. (Stretching after workouts, or the occasional yoga class, is advisable for everyone, he adds. Such postexercise stretching was not a part of the review, though.) Runners and cyclists can adequately warm up, Dr. McHugh says, by jogging or pedaling lightly. But he suggests that people who play basketball, soccer, tennis and ultimate Frisbee — or other sports that involve leaping, sprinting and forceful, potentially muscle-ripping movements — should stretch in advance. Those who haven’t stretched since childhood gym class might want to consider consulting an athletic trainer about the best upper- and lower-body stretches, particularly for the shoulders, hamstrings and thighs.