16 June 2012

Stretching away performance

Static stretching pre-exercise seems to hurt performance and make the workout quite a bit harder.


Sgt. Parsons stretches after completing the Army 10-Miler.
Photo by Dottie White.
Early morning before the start of a typical endurance event. Looking around one notices many athletes preparing themselves by stretching their limbs. Typically, the stretches are held for a relatively long time, between several seconds and more than 1 minute. This is static stretching. Years back most people were told that this is the way to warm-up and prepare for exercise.

Well, things have changed. Researchers tell us differently these days. There is strong evidence that static stretching before endurance exercise diminishes performance and increases the energy cost (1). This means, you will be slower and need more energy on top of it (deplete your glycogen stores earlier).

A study published in 2010 investigated the effects of static stretching on energy cost and endurance performance in trained male runners. Prior to a treadmill run they had the runners either stretching major lower body muscle groups for 16 minutes (5 different static stretching exercises) or sit quiet for the same time. The runs then consisted of a 30-minute easy segment followed by a 30-minute performance run where participants ran as far as possible without viewing distance or speed. They measured total calories expended during the first 30 minutes. Performance was determined by the distance covered during the second 30 minutes.

Without prior static stretching athletes ran significantly further (+3.4%) than in the stretched condition. In addition, after stretching energy expenditure was significantly greater (+5%) compared with the nonstretching condition. It was also shown that the negative effect of static stretching prior to or during endurance exercise lasts for at least 60 minutes (duration of test runs).

Interestingly, the negative relationship found between energy cost and flexibility in men does not appear to be present in female athletes. All subjects in the above study were male.

Science has not yet discovered what causes the observed performance diminishing effect. One possible explanation is that static stretching seems to negatively affect the ability of the muscle tissue to produce force.

Whatever the root cause may be, as a coach I strongly discourage static stretching prior to exercise or racing. This goes for male and female athletes, regardless. We start all our sessions with dynamic warm-up routines which offer many additional benefits over stretching (will be discussed in a future post).

During cool-down and in dedicated stretching sessions, static stretching still is of good use for helping with recovery and enhancing flexibility and range of motion around joints.

Take home message: as a performance oriented athlete avoid static stretching during your warm-up routine. Do a dynamic warm-up (subject of a future post) and save static stretching for after your workout / race. You will be able to perform better and you will need less energy (spare glycogen).


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References
(1) Wilson JM, Hornbuckle LM, Kim JS, Ugrinowitsch C, Lee SR, Zourdos MC, Sommer B, Panton LB. Effects of static stretching on energy cost and running endurance performance. J Strength Cond Res. 2010 Sep;24(9):2274-9. 
http://www.ncbi.nlm.nih.gov/pubmed/19918196

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