Stretching Before Exercising Weakens Muscles

The old presumption that holding a stretch for 20 to 30 seconds — known as static stretching — primes muscles for a workout is dead wrong. It actually weakens them. In a recent study conducted at the University of Nevada, athletes generated less force from their leg muscles after static stretching than they did after not stretching at all. 

http://science.slashdot.org/article.pl?sid=08/11/07/1421242&from=rss