In the 1970’s the running boom came and all over North America people got out and started a pursuit that has paid terrific health dividends for them over the ensuing years. Back then, popular thought had it that it was necessary to stretch all the major sporting muscle groups before your activity. Being more flexible would offer greater efficiency of motion and prevent injury. If you failed to stretch, injury was pretty much guaranteed, or so the thinking went. There was only one way to stretch and that was what is now referred to as static stretching. It’s the holding of a muscle on soft tension for a period of 30 to 60 seconds with the stretches repeated 3 to 5 times.
Well thank goodness for actual research. There have been many subsequent studies that prove early assumptions do not match actual outcomes. For years now researchers have been finding that:
- The more flexible you are, the less efficiently you run. In a test of middle distance runners of widely varying ability researchers at the Nebraska Wesleyan University, found that the better a runner did on a sitting, forward reach test, the worse was their running economy. (Running economy is defined as the amount of energy used to run at a given pace.) The thinking currently goes that there is an optimal length for muscles that lets them store stride energy, like an elastic band, and then quickly return that energy during the later part of the stride. This mechanism can account for 40 -50% of the energy involved in each step. The effect seems to be more pronounced in men, possibly because they have more overall muscle mass to store and return energy and perhaps because women are generally a little more naturally flexible thus diminishing the store and release phenomenon.
- Static stretching actually causes a temporary decrease in strength and power. Investigating running economy more thoroughly, researchers had 10 male runners do two 1 hour runs. The first 30 minutes was steady pace to measure economy and the second 30 minutes was as fast as possible. The results? 16 minutes of static stretching beforehand actually increased calories burned during the first half and decreased distance traveled in the second half, both measures of lower running efficiency.
- Multiple reviews of stretching study literature (there’s lots to review) has shown no significant association with static stretching reducing injury frequency. That conclusion was reached by the U.S. Centers for Disease Control in 2004 with an analysis of over 350 studies.
So what to do? The research is without question still a work in progress but some useful conclusions can be made. In the next post I’ll look at the alternatives to static stretching. They should be done before activity and do not have the same impact on performance. For those athletes, recreational or competitive, who do feel the need for static stretching as a way to maintain mobility or keep supple a previous injury, keep the stretches gentle and restrict it to after you have worked out.