Most of the athletic community believes that proper and consistent stretching provides a bevy of both direct and indirect physical and physiological benefits. Among these perceived benefits are: injury resistance; increased flexibility/range of motion; enhanced growth potential; reduced lactic acid build-up; better muscle recovery; and possibly even elevated IGF-1 levels.
Most of the athletic community believes that proper and consistent stretching provides a bevy of both direct and indirect physical and physiological benefits. Among these perceived benefits are: injury resistance; increased flexibility/range of motion; enhanced growth potential; reduced lactic acid build-up; better muscle recovery; and possibly even elevated IGF-1 levels. But is disagreeing with these beliefs the same as being wrong? Hmm, I seem to remember a couple of theories about the earth being both flat, and the center of the universe that were also quite popular. So, instead of merely gauging public consensus, let’s examine some of the substantial body of research on this topic.
One naturally assumes that the stretching of muscles and connective tissues (tendons and ligaments) prior to exercise would be the best way to prevent injury during said exercise, right? Well, not only is the research in this area inconclusive, but mounting evidence seems to support the exact opposite position. A one-year study of 1,543 athletes who ran in the Honolulu Marathon found only 33% of male runners who did not stretch were hurt, while a striking 47% of male runners who stretched regularly were injured (Lally D, 1994). The implication here is that stretching, at least among marathon runners, does not prevent injury. Furthermore, depending on how and when stretching is conducted, it may cause minute damages that serve as precursors to injury. Even when the research accounted for the fact that the strongest predictor of a future injury is a past injury, and excluded runners who took up stretching after a previous injury, stretchers who did not run any more miles than the non-stretchers still had a 33% greater risk of injury. However, this study also found that stretching after workouts reduced the risk of injury. The researchers here concluded that stretching should only occur when muscles have been thoroug
hly warmed, in order to be considered a protective measure.
In a similar study (van Mechelen W, Hlobil H, Kemper, et al., 1993) 159 runners who were instructed how to warm up, cool down, and stretch effectively were compared to a control group of 167 similar runners who received no instruction. The injury rates of the two groups were identical suggesting that the stretching instructions produced no protective benefit, and that stretching while presumed to be a productive endeavor has little effect in the area of injury prevention.
Now, as valid and reliable as these studies are, they alone don’t mean stretching regimens should be disregarded altogether, because as stated earlier the variance between study findings is rather broad. Let’s delve into the other side of this argument reviewing still more research that has determined stretching may be beneficial.
A study of military recruits who performed a series of static stretches before and after training were compared to a control group that did not stretch at all (Amoko et al, 2003). Although there was no difference in the rate of bone or joint injuries, the stretching group returned a significantly lower rate of muscle-related injuries. Static stretching, also know as active stretching, is when a position is assumed and then held with no assistance other than the strength of working (agonist) muscles. An example of this would be reaching forward to a point of tension and holding the stretch without the assistance of other body parts or apparatus. The tension of the agonists in an active stretch helps to relax the muscles being stretched (the antagonists).
In their review of this literature, Thacker et al (2004) stated that “There is not sufficient evidence to endorse or discontinue routine stretching before or after exercise to prevent injury among competitive or recreational athletes.” They also cited that “Further research, especially well-conducted randomized controlled trials, is urgently needed to determine the proper role of stretching in sports.”
So, what exactly should be concluded from such divergent studies? Well the conscientious observer might posit, “Since there’s so much difference within the research, I’ll just do what feels best for me.” Although this is often the wrong approach to training, or anything in life for that matter, it paradoxically enough is the absolute correct response here. One should indeed individualize stretching habits based on one’s own body’s responses to it. This is the only way to account for the considerable variation in the:
- baseline flexibility between individuals
- pliability within a person’s own body (e.g. flexible
- shoulders but inflexible hips or; flexible right hamstring, but tight and inflexible left hamstring)
- genetic predispositions
- history of injuries
- abnormal biomechanics
So, in the final analysis as illustrated by the above studies, at least for the present time, one should simply practice the Latin “Nosce te ipsum”, i.e., “Know thyself.”
- Amoko et al. "Effect of static stretching on prevention of injuries for military recruits." [Abstract]
- Lally D. 'New Study Links Stretching with Higher Injury Rates', Running Research News, Vol. 10(3), pp. 5-6, 1994
- Thacker et al. "The Impact of Stretching on Sports Injury Risk: A Systematic Review of the Literature". Medicine & Science in Sports & Exercise. 36(3):371-378, March 2004. [Abstract]
- van Mechelen W, Hlobil H, Kemper HCG, et al. Prevention of running injuries by warm-up, cool-down, and stretching exercises. Am J Sports Med 1993;21:711–19. [Abstract]
NOTE: THE ABOVE STUDIES CAN BE SWIFTLY ACCESSED BY CLICKING ON THE HYPERLINKED ‘ABSTRACT’.