We learned about all important stretching in our sixth grade gym class. Our coaches would have us touch our toes, twist our torsos and perform obligatory jumping jacks. It got the blood flowing and the tendons loosened. Stretching before any vigorous activity became entrenched in our collective unconsciousness and no one questioned it since. Until recently, when sports and exercise researchers began finding that static stretching is not only not good for us, but it can make our muscles weaker.