A new study finds that static stretching before running reduces running economy and performance.
Why would a static stretching warm-up make you run less efficiently? The authors of previous studies have speculated that static stretching warm-ups temporarily reduce musculoskeletal stiffness. While the word “stiffness” generally has negative associations with respect to athletic performance, a certain type of stiffness is beneficial to running performance. When you run, your legs function as springs that repeatedly bouncing off the ground, capturing “free” energy (i.e. energy that the body does not have to generate for itself) from each impact and using it to for forward thrust. Just as a loose mechanical spring (think of a worn automobile shock absorber) is less effective than a stiffer one, a less stiff leg (resulting from laxity at key muscle-tendon junctions) bounces less effectively off the ground during running. Consequently, the leg captures less “free” energy from the ground and running economy is reduced.
Saturday, November 21, 2009
Some confirmation of some information in a previous post: