Update: How important is stretching to avoid injuries? A recent study from the American Journal of Sports Medicine (Vol. 27:2, 1999) found that hamstring (back of the leg) flexibility affected the rate of injury during a military basic training course.
Nearly 300 trainees were divided into two groups for basic training. One group received minimal hamstring stretching as part of their training, while the other had an additional three daily sessions of hamstring stretching.The group that stretched more not only improved flexibility, participants also suffered fewer lower leg injuries. The incidence of injury in the group that stretched was about 17 percent as compared to a 29 percent rate for the group that stretched less.
Although this was a simple study in terms of design, and basic training is not all that similar to the typical workout program, the results do seem to confirm the advice most fitness experts give regarding flexibility: stretch -- after you warm up and after you exercise.
The January issue of Running & FitNews suggests that all runners (and this would apply to exercisers using any mode of activity) make flexibility one of the major training objectives in its own right. This suggestion is supported by the American College of Sports Medicine which has suggested that flexibility be part of every fitness program along with cardiovascular endurance and strength programs. Too many exercisers focus only on endurance and ignore the benefits of adding strength and flexibility.
So how do you stretch properly and what stretches are important? The following guidelines are from "Exercise: A Guide from the National Institute on Aging."
Do stretching exercise three to five times at each workout session
Slowly stretch into the desired position, as far as possible without pain, and hold the stretch for 10 to 3 0 seconds. Relax, then repeat, trying to stretch farther. Note: If you have had hip replacement therapy, check with your doctor before doing lower body exercises.
Always warm up before stretching. Stretching should NOT cause pain. If it does, you are stretching too far. Never bounce; jerking motions can cause muscles to tighten and maybe injure them.
Avoid "locking" your joints into place when you straighten them during stretches. Your arms and legs should be straight when you stretch them but not locked.
Here is a list of muscles you should stretch as well as some stretching exercises:
1. Hamstrings: There are several ways to stretch the muscles in back of the thigh. One is to sit sideways on a bench or other hard surface (such as two chairs placed side by side) with your left leg resting on the bench (or chairs), toes pointing up. Your right leg should be on the side of the bench with the foot flat on the floor. If your left knee is bent, stretch to get it to lie flat on the bench. If you feel a stretch in this position, hold for 10 to 30 seconds. If not, lean forward from the hips (not the waist) with the upper body until you feel a stretch. Hold. Reverse legs and repeat three to five times.
Another way is to stand behind a chair with your legs straight. Hold the back of the chair with both hands. Bend forward from your hips (not waist), keeping your entire back and shoulders straight, until your upper body is parallel to the floor. Hold position for 10 to 30 seconds. Repeat three to five times.
2. Calves: To stretch lower leg muscles, stand a foot or two from a wall and reach to the wall with your arms extended. Keeping your left knee slightly bent, and the toes of the right foot slightly turned inward, move your right foot back one or two feet and lower your heel to the floor. You should feel a stretch in your right calf, but you should not feel uncomfortable. If you don't feel enough stretch, move the foot even further back and straighten the knee and hold for 10 to 30 seconds. Alternate legs and repeat 3 to 5 times.
I'll list some more exercises for flexibility in the next column.
Garth Fisher is director of the Human Performance Research Center at Brigham Young University.