Pre Exercise Stretching – Why You Should Stop Immediately
We will occasionally get questions from patients regarding the benefit stretching, or it will come up in conversations about what is happening outside of the office with regard to physical activities.
It seems that the conventional wisdom is that stretching is good for you, but as it turns out; not only is the evidence for the supposed benefits of stretching inconclusive, it appears that it can actually cause problems.
Most people who stretch, when pressed for reasons, say they do so in an attempt to either decrease pain or other symptoms, or because they have been told that it helps prevent injury or improves performance during strenuous physical activity. As it turns out, there are problems with both of these ideas. We will address the second issue in this post, and follow up in the next post talking about the problems with stretching for pain relief.
Stretching makes us more injury-prone.
One example, A 1994 study (‘New Study Links Stretching with Higher Injury Rates,’ Running Research News, vol. 10(3), pp. 5-6, 1994)
Showed a 33% higher rate of injury among runners in the Honolulu Marathon who stretched, even controlling for those who had previous injuries and would therefore be more likely to re-injure for other reasons.
One study published April 2013 in The Journal of Strength and Conditioning Research, concluded that if you stretch before you lift weights, you may find yourself feeling weaker and wobblier than you expect during your workout. Those findings join those of another study from Croatia, a very comprehensive re-analysis of data from earlier experiments that was published in The Scandinavian Journal of Medicine and Science in Sports. Together, the studies augment a growing scientific consensus that pre-exercise stretching is generally unnecessary and likely counterproductive.
Stretching reduces muscular performance, making us weaker.
For the more wide-ranging of the new studies, and to partially fill a knowledge gap, researchers at the University of Zagreb began combing through hundreds of earlier experiments in which volunteers stretched and then jumped, dunked, sprinted, lifted or otherwise had their muscular strength and power tested. For their purposes, the Croatian researchers wanted studies that used only static stretching as an exclusive warm-up; they excluded past experiments in which people stretched but also jogged or otherwise actively warmed up before their exercise session.
The scientists wound up with 104 past studies that met their criteria. Then they amalgamated those studies’ results and, using sophisticated statistical calculations, determined just how much stretching impeded subsequent performance.
The numbers, especially for competitive athletes, are sobering. According to their calculations, static stretching reduces strength in the stretched muscles by almost 5.5 percent, with the impact increasing in people who hold individual stretches for 90 seconds or more. While the effect is reduced somewhat when people’s stretches last less than 45 seconds, stretched muscles are, in general, substantially less strong.
They also are less powerful, with power being a measure of the muscle’s ability to produce force during contractions, according to Goran Markovic, a professor of kinesiology at the University of Zagreb and the study’s senior author. In Dr. Markovic and his colleagues’ re-analysis of past data, they determined that muscle power generally falls by about 2 percent after stretching.
And as a result, they found explosive muscular performance also drops off significantly, by as much as 2.8 percent. That means that someone trying to burst from the starting blocks, blast out a ballistic first tennis serve, clean and jerk a barbell, block a basketball shot, or even tick off a fleet opening mile in a marathon will be ill served by stretching first. Their performance after warming up with stretching is likely to be worse than if they hadn’t warmed up at all.
A similar conclusion was reached by the authors of the other new study, in which young, fit men performed standard squats with barbells after either first stretching or not. The volunteers could manage 8.3 percent less weight after the static stretching. But even more interestingly, they also reported that they felt less stable and more unbalanced after the stretching than when they didn’t stretch.
There have been quite a few studies done on how stretching affects injury rates, Delayed onset soreness, and other effects of stretching with respect to muscle performance, injury and recovery, and the results pointed to either no effect/ negligible effect or they were unfavourable toward stretching.
We can safely say that the evidence shows no conclusive benefit of stretching to improve muscle performance and recovery (quite the opposite), but what about alleviating back pain? We will address that in the next post.
If you would like to learn more about how we correct bodies and alleviate pain, please come in for a free consultation and see how ABC™ may benefit you.