When you've pushed your body harder, exercised longer or performed some type of new resistance training, you'll probably feel at least a bit of soreness in the following days. You may be tempted to stretch those muscles to ease some of that pain, but that could be a waste of time. In spite of a prevailing notion to the contrary, numerous studies have found that stretching does not actually relieve sore muscles.
Delayed-Onset Muscle Soreness
When you're sore after exercising, you're experiencing what's known as delayed-onset muscle soreness, or DOMS; it's thought to be the result of damage to the muscle fibers as a result of training harder than the body is accustomed to. According to the American College of Sports Medicine, DOMS happens as a result of the lengthening of a muscle while under force, called an eccentric muscle contraction.
Stretching is Lengthening
Now consider that information about eccentric muscle contraction and how it relates to stretching. When you stretch a muscle, you're also lengthening that muscle. When you think of it that way, it makes it easier to understand why stretching after a hard workout isn't going to help relieve sore muscles. Think of it this way: if you hurt yourself doing a certain activity, repeating that activity is probably not going to relieve the pain. In research studies, some people have experienced slight pain reduction from stretching, but the results were not significant enough to recommend stretching as a viable form of pain relief, suggests The BMJ, formerly the British Medical Journal.
The Nervous System Response
When you feel pain, it's a result of your nervous system sending a signal to a part of the body, telling it to hold off on more movement or potentially-damaging activity. Pain, in other words, is a mechanism of protection. Stretching an area in pain, then, is likely to elicit an even bigger nervous system response, not a smaller one. If you're experiencing muscle soreness, time is your best ally, suggests the ACSM. Wait a few days to rest your muscles, and when you go back to the same exercise, you'll probably find your muscles have adapted and you won't be as sore the next time around.
If you're still not convinced that stretching to relieve soreness is a waste of time, a number of studies may shed some more light on the issue. One review published in 2011 in the "Cochrane Database of Systematic Reviews" looked at 12 studies that examined this issue, and concluded that stretching before, after or during a workout will not reduce soreness. A review published in 2002 in the "British Medical Journal" concluded the same thing.