Stretching - for how long?

Misunderstanding exists about the ability of stretching to reduce injuries and relieve discomfort and stiffness.  We often read about different recommendations for stretching. Recommendations prescribed will cater to the requirements and condition of the individual.
Long term results of stretching in human subjects have shown after six weeks, those people that stretch 30 seconds/muscle every day increased their range of motion more than the people stretching 15 seconds/muscle/day. Small increases in range of motion within the group that stretched 15 seconds/day turned out to be statistically insignificant. No further increases were seen in people stretching 60 seconds when compared to those  stretching 30 seconds.

This study  supports use of 30 sec. stretches when designing a generalized  program and would be appropriate for group classes in which you are catering to mostly healthy individuals; however, physiotherapists will treat individuals as opposed to groups. In other studies involving human subjects, some increased their range of motion using only 15 sec. stretches while some others would gain very little even with 45 sec. stretches.

All current studies have been done using healthy humans. Muscle fatigue will decrease viscoelasticity and therefore we can predict that when we are dealing with torn muscles and tendons, muscle atrophy, weakness, and scar tissue that viscoelasticity will also be different than that found in healthy humans. Rather than giving  everybody the same stretch routine, physiotherapists  will individualize their prescription to allow for differences within individuals and amongst healthy and injured soft tissues. We will also advise patients who are stretching to avoid pain in most cases depending on the goal of the stretch. When holding a stretch, the muscle will relax reflexively and therefore the forces on muscle decreases. When less tension is felt due to reduced viscoelasticity and the analgesic effect, patients then simply stretch further, increasing the muscle length until they again feel tension.


Passively warming a muscle  prior to a stretch, or icing while stretching can increase the range of a stretch but is not effective in the prevention of injury. People who participate in active warm up prior to performing a stretch seem to obtain the most benefit in terms of gaining range of motion. Contrary to what people believe, performing a warm up without actively stretching will not improve range of motion. Stretching with the application of heat is shown to increase range of motion more than stretching without the heat.  The application of cold in the initial stages of performing a stretch is helpful to improve range of motion while stretching. This mechanism is believed to be due to an analgesic effect.


It is thought that light active warm up will raise tissue temperatures, reduce muscle stiffness, and thereby improve range of motion.  Studies involving human muscles have shown that effectiveness of a warm up in decreasing stiffness is related to the type of exercise used for the warm up and the particular muscle tested. For instance, running as a warm up will reduce stiffness in  calf muscles but not hamstrings, and in some studies running did not have any effect on range of motion of the hamstrings

Activity by itself will not have a significant effect on mobility. Research consistently shows that there are greater increases in range of motion after stretching that follows an active warm up as opposed to stretching alone. That research is the basis for recommendations to warm up prior to stretching. This should not be interpreted as stretching prior to exercise will prevent injuries. 

This information is not intended as a substitute for medical advice. If you are looking for information related to a particular condition, see your family physician.