A recent study showed that a group of runners who stretched three times a day, and became more flexible, reduced their risk of lower leg injuries by 12% over runners who did minimal stretching. This is one of the few studies confirming the benefits of stretching. Does it mean you should stretch? Does stretching reduce your risk of injury? Does it aid performance? it's too early for science to tell us...but if you listen to successful runners and coaches, they value flexibility.

Most runners understand that stretching is an important part of a good fitness and training plan, but stretching may often get shortchanged. If your time is at a premium (and whose time isn't) you may resent trading miles for stretching. If you've got 45 minutes to work out, it may seem like a waste to devote any of it to stretching. Although it may be best to warm up prior to exercise, stretch before and then stretch again after exercise, many runners simply want to lace up their shoes and head out the door. You can probably have your cake and eat it too. That is, have your run and perform stretches to decrease your risk of injury and enhance your performance. Effective stretching can take as little as five minutes.

Starting out with an easy jog for about five to ten minutes before you run at your full speed is a natural warm up. Pausing to stretch the major muscle groups you are using (such as the quadriceps, hamstrings, and calves) may help to reduce your risk of injury and can loosen your stride for better performance. After your run, devote more time to stretching and focus on those areas that are tighter than others. And even with all this, it still doesn't have to take long to be effective.

The recommendation to warm up prior to stretching is based on the fact that you should never stretch a cold muscle. Imagine trying to stretch a cold piece of taffy. You can't, and if you continue to try, it may break. But if you warm up the taffy, it becomes pliable and easier to stretch. Muscles behave much the same way. When warm, they become more flexible and less susceptible to injury from either stretching or exertion.

Does that mean you have to work up a sweat before you stretch? As long as your muscle isn't cold, stretching can be done any time, and your body benefits even from casual stretching. The intensity of the stretch should be adjusted depending on how warm the muscle is. After a run, when the blood is pumping and the body is generating heat, the muscles will be more flexible and easier to lengthen. Now stretching can be slightly more aggressive.

Remember that stretching is not a competitive sport. It's not meant to make you as flexible as the kid down the street, or as limber as the gymnast next door. The goal for stretching should be to achieve flexibility within the range a sport requires and to counteract any inflexibility caused by sitting all day at a desk, driving long hours, or standing in one place all day. And, when getting ready to work out, stretching prepares the body for movement and helps make the transition from inactivity to vigorous activity without strain. It is in your best interest to stretch in order to maintain flexibility. Losses in flexibility show up for the runner as a shortened, less fluid running stride and higher risk for pulling or tearing muscles when running. A strong, stretched muscle resists stress better than a strong, unstretched muscle.

There are several effective methods for stretching but some require partners or are best learned through one-on-one instruction. In many cases, the more complicated something is, the less you use it. Therefore, static stretching is often recommended. It is easy to understand and perform. With static stretching, you lengthen the muscle to where there is a mild pull and hold without bouncing. In the past, it has been recommended to hold a static stretch anywhere from 20 seconds. However, recent research indicates that it is more effective to hold a stretch for approximately 10 seconds, release, and then repeat the same stretch two to three times. As the stretch is repeated, the muscle relaxes, and you avoid over-stretching, which can lead to injury. If you experience extreme discomfort or the muscle quivers uncontrollably during the stretch, back off a degree or two.

Never start an aggressive stretching program when you are acutely injured. This could lead to additional damage of the injured area. Allow time for healing. When there is minimal or no pain, start a light and easy stretching regime. Stretching is sometimes part of an injury-recovery program, in which case you should follow the instructions of your sports medicine professional. (Barbara Baldwin, M.P.H., is The American Running Association's resident Information Specialist. To receive The American Running Association's newest brochure on "Stretching for Runners, "send a business-sized, self-addressed stamped envelope to Stretching, do The American Running Association, 4405 East West Highway, Suite 405, Bethesda, MD 20814.)