UPFRONT | Columnist STRETCHING To stretch or not to stretch? O What you need to know about warm-ups BY DAVID GEORGE BEHM, ANTHONY BLAZEVICH, ANTHONY DAVID KAY, GABRIEL S. TRAJANO important role in whether stretching is actual performance. So why for the last 20 years have we good or bad. Furthermore, when asked been told that static stretching should immediately after a warm-up, athletes be removed from the warm-up? One reported feeling more likely to perform major problem is that most of the re-well when muscle stretching was in-search studies asked participants to cluded than when omitted. If stretching might not improve per-stretch for much longer than most ath-letes do in a warm-up. Professional formance, why include it at all? The athletes may stretch for only 12 to 17 most obvious reason is that stretching seconds per muscle, on average, but increases the range of motion of the most research studies asked participants joints through its effects on muscles and to stretch each muscle for longer than the nervous system. That is, there is an one minute, with some studies imposing improved capacity to move with ease during activities that need an enhanced 20 or even 30 minutes of stretching. Furthermore, the participants’ per-range of motion. formances are often tested almost im-Also, most muscle and tendon inju-mediately after the stretching, whereas ries occur when the muscle is being athletes always complete further stretched during vigorous activities. warm-up and then do other things, like Muscle stretching not only increases listen to final instructions from coaches, joint range of motion but also allows the finalize preparations or sing a national muscle to exert more force when at anthem. When these tasks are included longer lengths. Our review found that in studies, the negative effects of static this effect is seen even in studies show-ing a loss of force measured in tests at stretching are not seen. It’s also important to remember that short muscle lengths. We can also use stretching as a form study participants are often university students who have often learned in their of self-diagnosis, checking different re-gions of the body for soreness studies that static stretching or tightness before or after can cause performance im-pairments. That is, there is the sports and exercise. Also, mus-possibility of a nocebo (nega-If stretching cle stretching can decrease might not tive placebo) effect. In one muscle tone, heart rate and study, students without in-blood pressure, reduce anxiety improve struction about static stretch-performance, and improve the function of ing research were told that our blood vessels. then why stretching would actually im-include it at So, static stretching is back, prove performance (they were albeit with some caveats. The all? primed for a placebo effect). benefits of static stretching This instruction resulted in before exercise seem to out-weigh the disadvantages when increased muscle strength af-ter static stretching. the stretching is incorporated into a full So, the power of the mind can play an warm-up and when the duration is reasonable (less than 60 seconds per DAVID GEORGE BEHM , University Research Professor: School of Human Kinetics and Recreation, Memorial muscle group). University of Newfoundland; ANTHONY BLAZEVICH , Professor of Biomechanics, Edith Cowan University; This article is republished from ANTHONY DAVID KAY , Professor of Biomechanics, University of Northampton; GABRIEL S. TRAJANO , under a Creative Senior lecturer, Queensland University of Technology Commons licence. January/February 2021 Chiropractic and Naturopathic Doctor 15 nce considered an essential part of any sport or exer-cise warm-up, static stretching has now been removed from the picture almost entirely. This move followed extensive research showing that static stretching can reduce muscle strength (reflected in things like lifting weights), power (for example, jump height), run-ning speed, balance and other capacities for a short time after the stretching. To put the research into context, the average performance decrease (decrease in strength, power, speed) after static stretching across all studies is about-three to five percent. It may not sound like much, but if you consider that Us-ain Bolt beat Justin Gatlin by 0.8 per-cent and Andre de Grasse by one per cent at the 2016 Olympics, then it’s safe to say that a three to five percent deficit could be life-changing. However, it seems that many of these studies were not designed to answer the specific question of whether stretching affects performance when used in a warm-up or, at least, we may have made conclusions contrary to the actual evi-dence. In our recent review of the re-search, we found that these studies tell a different story. When looking at only those studies where participants performed muscle stretching within a full sport warm-up – that is, when lower-intensity exercise is done before static stretching of less than 60 seconds per muscle, and high-er-intensity sports-specific exercises are performed after stretching – then static stretching within this comprehensive warm-up has no significant effects on www.Cndoctor.ca Photo: Credit tk here
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