There is little scientific evidence that stretching helps to prevent athletic injuries.
However a survey of high school coaches in Michigan shows that almost all stretch their athletes for an average of 13 minutes prior to practice or competition.
Almost 95 percentof coaches believe that stretching helps to prevent injuries, and nearly 73 percent feel that there are no drawbacks to stretching (Clinical Journal of Sport Medicine, May 2006).
They felt that their personal experience and scientific evidence support their stretching practices.
Before you decide that scientific research always is more correct than coaches' opinions, realize that many athletic principles were used by coaches long before the scientific community showed evidence to support them.
Runners have used interval training for more than 90 years and the first scientific evidence to explainits benefits was published just this year.
Muscles tear because the force on them is greater than their inherent strength, so injuries should be prevented by strengthening muscles, not by stretching them.
There is data to show that stretching elongates muscles and tendons to allow a greater torque about a joint, which allows athletes to throw further, lift heavier, run faster, and jump higher.
There is no good scientific data to show that stretching prevents injuries, but It may.
Coaches and scientists do agree that you should not stretch cold muscles, so if you choose to stretch before your workout, warm up your muscles first.