We have all been doing those stretches before starting on our respective fitness routines, because we have always been told that it is good for us. For years we have been told to get our muscles supple and limber by stretching before starting a workout, but now it would seem this was actually bad advice.
Fitness experts now tell us that “static stretching” (bending to touch your toes, stretching the leg over a fence etc) may actually be harmful. We may think that this helps to loosen muscles but in fact it can actually further tighten them!
Think of a rubber band being pulled to the limit; it is more likely to snap then. Similarly, stretching your muscles to a limit makes them more prone to injury and damage; so that you are more likely to pull a muscle with this kind of stretching. Static stretching before a sport also makes you slower and lowers performance.
Rather than this kind of stretching, light jogging, or kicking a football around for a time etc could be more beneficial. This enhances the heart rate and blood flow to the muscles and raises the body temperature in preparation for the workout much more effectively. Now a full range of motion is possible in a more coordinated way.
Source: USA Today