Health Options Alan Titchenal  & Joannie Dobbs                    Monday, October 4, 2004

The benefits of stretching differ with various sports

To stretch or not to stretch? That is the question. Surprisingly, this common practice has little scientific evidence to support it. Research shows that flexibility might be important for performance and injury prevention in certain activities, but not others. Too much flexibility could even impair some sports performance.

Question: What makes a person more or less flexible?

Answer: Muscles move the body by pulling on tendons attached to bones. When both muscle and tendon have more elasticity, they can respond to high stresses by stretching rather than by being damaged. Scientists who study stretching (stretchologists?) refer to this flexibility as "compliance of the muscle-tendon unit."

In other words, if someone is flexible, the combination of muscle and tendon is not rigid and can flex when stressed. Performing stretching exercises regularly can increase flexibility of both muscles and tendons.

Q: Does stretching help sports performance?

A: Being flexible might benefit performance in sports such as basketball, football and soccer that involve a lot of bouncing and jumping. These types of movement expose muscles and tendons to rapid, high-intensity stretching and shortening. Flexibility helps the body handle these stresses and is likely to benefit performance.

In contrast, it appears that people with low flexibility perform the best in sports such as jogging, cycling and swimming that involve mainly lower-intensity repetitive movements. Researchers believe this happens because muscles and tendons that are less flexible impart energy from muscle to bones more efficiently. It is like having a strong, stiff spring to pull on the bones rather than a weak and flexible one.

Q: Does stretching help prevent injuries?

A: Stretching likely protects against injury from activities that involve high-intensity, explosive actions. Studies show that tendons are temporarily less stiff immediately after a single bout of stretching exercises. If a regular program of stretching is repeated daily for several weeks, tendons tend to stay more flexible. Consequently, frequent regular stretching, especially before exercise, is likely to provide some injury protection for those participating in high-intensity activities.

Joggers and swimmers are less likely to need the protection afforded by stretching. For them it is a matter of striking a balance between staying reasonably flexible, but not so flexible that they get "soggy" tendons and lose their "snap."

For most of us, maintaining flexibility is an important component of fitness. Like strength and endurance, flexibility tends to decline with age. But it doesn't need to.

If you are new to stretching, consult a qualified fitness professional for guidance on proper technique. Usual guidelines include: Warm up before stretching, stretch every day, stretch slowly and easily with low levels of force, hold stretches comfortably for 15 to 30 seconds, and repeat each stretch four to five times.