Why Stretching is Doing the Opposite of What You Think it Does

Stretching is a form of exercise that everyone thinks they should do, but most people don’t do. It’s often neglected or rushed in your workouts, especially if you’re crunched for time. Luckily, if you’ve neglected your stretching, you’re doing something right.

Stretching is the act of placing your tissues under tension, holding that tension for an extended period of time, to allow those tissues to relax. People generally use stretching to warm up, cool down, and increase flexibility. Increasing flexibility is not a bad thing, but are there better ways to do it?

Stretching allows tissues to relax via muscle spindles. These are stretch receptors in the belly of the muscles, that sense the length of that certain muscle. When a muscle is lengthened in a stretch, so are these muscle spindles. Initially the response relayed from the spinal cord is for the muscles to contact, which allows you to not stretch this muscle any more. After holding this stretch, the muscle spindle habituates to it’s new length, contracting less, and giving the muscle more length or flexibility.

Now a muscle has better length, potentially allowing for better motion at the joint this muscle supports. In a healthy person who does not live a physically demanding life, this new muscle length usually does not have any consequences. However, if we look at an athlete, or someone with musculoskeletal pain, is this new flexibility useful?

If we revisit the mechanism of the stretch, placing the muscle under tension makes the muscle relax more. If we then ask the muscle to contract or create tension, the muscle is still in this relaxed state, and is not able to contract as effectively as before. Why does this matter? Lets look at two scenarios.

A high school baseball pitcher gets to the field early to warm up. He pulls his arm across his chest, stretching the posterior shoulder muscles, following it with pulling his arm behind his head, stretching his triceps. Later, when he’s pitching in the game, those posterior shoulder and triceps muscles are now lengthened, and not able to contract as well. If these muscles are not able to contract as well, this can overload the muscles in the front of the joint, making them contract more. Multiply this for multiple pitches, innings, and games, and suddenly our pitcher is losing control and placement in his pitches, and developing anterior shoulder or elbow pain as the season progresses.

If we look at a person with low back pain, they might have googled some exercises to help their back. They find some piriformis and low back stretches, and think they may help. When this patient find minimal, short term relief from them, they may think they need to perform them more for longer lasting relief. The more hip stretching performed gives this patient more hip flexibility, but makes the lumbar muscles compensate and contract more to stabilize. This leads to long lasting and chronic low back pain, no matter what the patient does.

Although these are very simple scenarios, hopefully they illustrate the potential harmful effects of easy stretching. Any athletes or person experiencing musculoskeletal pain should NOT be passive stretching. Stay tuned for more articles about what you should be doing instead to gain flexibility or other things detrimental to health and performance.