Be careful how you stretch when you exercise

Philip J. Goscienski, M.D.

March 2011

Misconceptions abound in the matter of stretching, the worst one being that stretching before exercise improves performance and prevents injury. It does not. Studies of runners, gymnasts and competitive golfers reveal that performance actually is diminished if stretching occurs before the activity.

There is no clear-cut evidence that stretching itself lowers the risk of injury, although that is the usual reason for recommending it. The actual benefit may come from the warm-up that most coaches advise before a stretching routine. It causes more blood to flow through previously dormant, unopened blood vessels so that they can deliver nutrients and remove waste products more efficiently. Rapid removal of normal accumulations of waste products might explain why a proper stretching routine, which includes an adequate warm-up, seems to make muscle activity less painful, the so-called analgesic effect.

A warm-up may require no more than 3 to 5 minutes on the treadmill, stepping in place or even a brisk walk from the far corner of the parking lot at the fitness center. If your exercise consists of walking, jogging or running, start slowly and gradually work up to speed.

Stretching does not provide much benefit to tendons and ligaments. Tendons attach muscle to bone and ligaments hold bones together. They have relatively few blood vessels — hence their pale color — and they don't have much capacity to stretch, especially in older persons.

Stretching makes muscles less stiff so that the range of motion of a joint becomes a little greater. That doesn't happen immediately and sometimes it takes a few weeks or longer for the benefit to become apparent. The effect varies between individuals and even between muscle groups in the same person.

The most practical time to stretch is actually between sets of exercise. Rest intervals should last about one minute, during which you can stretch the muscles just worked. Twenty to thirty seconds seems to be the proper duration for a stretch. Holding a stretch for more than a minute has no increased benefit.

When holding a stretch there should be a feeling of tension and perhaps a little discomfort but not actual pain. The movement should be slow and steady. Rapid, bouncing stretches do little good and they are likely to result in injury.

Persons who have had torn muscles or ligaments should consult a physical therapist before restarting any exercise program.

Philip J. Goscienski, M.D. is the author of Health Secrets of the Stone Age, Better Life Publishers 2005. Contact him at