Over the past 20 years, static muscle stretching has gotten a nasty rap. Once considered an important a part of any sport or exercise warm-upstatic stretching has now been faraway from the image almost entirely.
This move followed extensive research showing that static stretching — where we stretch after which hold the muscle at an prolonged length for seconds or minutes — can reduce muscle strength (reflected in things like lifting weights), power (for instance, jump height), running speed, balance and other capacities for a short while after the stretching.
To put the research into context, the common performance decrease (decrease in strength, power, speed) after static stretching across all studies is about three to 5 per cent. It may not sound like much, but in case you consider that sprinter Usain Bolt beat Justin Gatlin by 0.8 per cent and Andre de Grasse by one per cent on the 2016 Olympicsthen it’s secure to say that a 3 to 5 per cent deficit may very well be life-changing. So, at first glance it might appear reasonable for static stretching to be faraway from the image.
However, it appears that evidently lots of these studies weren’t designed to reply the particular query of whether stretching affects performance when utilized in a warm-up or, no less than, we could have made conclusions contrary to the actual evidence.
A re-assessment on the research
In our recent review of the research, we found that these studies tell a special story.
When taking a look at only those studies where participants performed muscle stretching inside a full sport warm-up — that’s, when lower-intensity exercise is completed before static stretching of lower than 60 seconds per muscle, and higher-intensity sports-specific exercises are performed after stretching — then static stretching inside this comprehensive warm-up has no significant effects on actual performance. For example, average change in sprint speed was -0.15 per cent.
So why for the last 20 years have we been told that static stretching ought to be faraway from the warm-up?
One major problem is that the majority of the research studies asked participants to stretch for for much longer than most athletes do in a warm-up. Professional athletes may stretch for less than 12 to 17 seconds per muscle, on averagebut most research studies asked participants to stretch each muscle for longer than one minute, with some studies imposing 20 or even half-hour of stretching.
Furthermore, the participants’ performances are sometimes tested almost immediately after the stretching, whereas athletes at all times complete further warm-up after which do other things, like take heed to final instructions from coaches, finalize preparations or sing a national anthem. When these tasks are included in studies, the negative effects of static stretching should not seen.
Nocebo effect
It’s also vital to do not forget that the study participants are sometimes university students, and these students have often learned of their studies that static stretching may cause performance impairments. That is, there may be the potential of a nocebo (negative placebo) effect. In one study, students without instruction about static stretching research were told that stretching would actually improve performance (they were primed for a placebo effect). This instruction resulted in increased muscle strength after static stretching.
So, the facility of the mind can play a crucial role in whether stretching is sweet or bad. Furthermore, when asked immediately after a warm-up, team-sport athletes reported feeling more prone to perform well when muscle stretching was included than when omitted. So preparing the brain for exercise could also be as vital as preparing the muscles.
The case for stretching
If stretching may not improve performance, why include it in any respect?
The most blatant reason is that stretching increases the range of motion of the joints through its effects on muscles and the nervous system. That is, there may be an improved capability to maneuver with ease during activities equivalent to sprint running, hurdling, being placed in extreme positions in wrestling, performing the splits in dance or gymnastics, playing soccer, hockey and other activities that need an enhanced range of motion.
Also, most muscle and tendon injuries occur when the muscle is being stretched during vigorous activities. Muscle stretching not only increases joint range of motion but additionally allows the muscle to exert more force when at longer lengths. Our review found that this effect is seen even in studies showing a lack of force measured in tests at short muscle lengths. Together, these changes may reduce the possibility of injury.
But that’s not the top of the story, as muscle stretching also has other benefits. We can use stretching as a type of self-diagnosis, checking different regions of the body for soreness or tightness before or after sports and exercise. Also, muscle stretching can decrease muscle tone, heart rate and blood pressurereduce anxiety and improve the function of our blood vessels. So, stretching may play a crucial role in maintaining cardiovascular health and promoting rest.
So static stretching is back, albeit with some caveats. The advantages of static stretching before exercise appear to outweigh the disadvantages when the stretching is incorporated right into a full warm-up and when the duration is affordable (lower than 60 seconds per muscle group).