The Dangers of Stretching
Most of us have heard it from our earliest years in school. And still today, we usually think of stretching as the start of any exercise. Even people who don't work out think of stretching as a good way to rid the body of aches and pains, and so called tight muscles. Go to any fitness center and everyone does it. But why?
The best answer may be tradition. Stretching is just something many people do, and have done for a long time. And like most traditions, it's hard to change even if we find it's not so good after all.
But is it good for you? There's really very little scientific information demonstrating that static stretching is good. As a matter of fact, there's quite a bit of evidence showing it's harmful. The author of this journal paper, Donald Murphy, D.C., (in "A Critical Look at Static Stretching: Are We Doing Our Patients Harm?" from Chiropractic Sports Medicine Volume 5, Number 3, 1991) presents the different reasons why people stretch and why those reasons are not valid.
Perhaps the most common reason people give for stretching is injury prevention. But this has never been shown to be true. Murphy sites several studies which show the opposite: static stretching can increase the risk of injury! One of many examples given is the hamstring muscles. It is both the most frequently injured muscle group and the most stretched.
Many people insist that stretching prevents injury by increasing their flexibility or range of motion. This may be true. But the cost may be muscle tightness or decreased muscle ability (hypoactivity), resulting in the possibility of injury. The types of injury created by stretching may be in the muscle itself, the tendon and ligament associated with that muscle, and/or even the joint controlled by that muscle.
Another common tradition is the idea that stretching is associated with warming up. If you exercise, the warm-up is vital. It increases blood flow through the muscles, preparing them for better function. But stretching will not do this so it cannot be classified as a warm-up. Cooling down is also associated with stretching. But this ending to exercise is not helped by stretching, nor is the muscle soreness associated with some types of exercise. (The best warm-up and cool down is accomplished by a gradual increase, and decrease, of exercise intensity as regulated by the heart rate.)
Many athletes stretch thinking it will help performance. But studies have shown this is not the case. As Murphy states, "there are several physiological mechanisms by which static stretching can not only fail to improve athletic performance, but may actually hinder such improvement."
Breaking tradition, even in the light of scientific evidence, is an extremely difficult task. For many people, the time put into stretching may be better spent with an easy aerobic exercise. This, combined with a proper warm up and cool down, can give total body benefits, including flexibility, which stretching can not provide.