This post has been updated. It was originally published on June 1, 2019.
Stretching is good for your muscles—no newsflash there. Research shows that an active warmup before a workout prepares them for the intense activity, and a static cool down (you remember those circle-up and stretch exercises from elementary school?) helps the body relax and recover.
But is it possible to overstretch? We’ve all had that moment: You stand up or lean back to stretch, and, all of a sudden, extreme pain hits. Can a benign extending and lengthening session turn detrimental?
It’s entirely possible that you could stretch so much that you strain, or even tear, a muscle, but more likely than not, that pinch is probably just a startled nerve. Muscles contain special sensory receptor cells called muscle spindles. When you stretch, these cells send a signal to the neurons within the muscle to tell the central nervous system that you’ve gone too far. As a result, those muscles contract, tighten, and resist the pull. That reaction is what causes the initial painful feeling that people get when they attempt to stretch. It’s also the reason that some people feel such agony when they try to touch their toes: The quick pain caused by that neural cascade is just too great.
There is hope, though. You can prime your muscles to avoid the painful twinge of startled neurons, according to Jeffrey Jenkins, a physiologist at the University of Virginia School of Medicine. It’s simply a matter of patience. If you hold a stretch for 6 seconds or more, the reflex lessons. That’s because, at that point, the muscle’s golgi tendon organs (spindles of neurons that rest on muscle fibers) react and inhibit those ouchy muscular contractions. Finally, your muscles can relax, stretch, and lengthen.
Jenkins notes that if you have the mental fortitude to get past that those 6 seconds, you no longer feel the pain and can indeed improve your flexibility. However, if you are enduring a ton of agony, stop, as you could be tearing a muscle. In fact, it’s quite difficult to differentiate between a tear and the pain that comes along with the first moments of a good stretch.
The best thing to do is to know yourself—and your pain threshold. If you feel like you are in a level of discomfort that is far beyond what you normally experience, you should probably stop. At that point, the likelihood of you benefiting from the stretch versus the likelihood of you pulling or tearing a muscle tips. Indeed, in a small study published in 2017, researchers tested and compared the benefits and risks of static stretching to the point of pain in 22 physically active women. One group stretched to the point of true pain, whereas another group went only to the point of discomfort. Pushing yourself to the point of pain, the study found, had no advantages.
So, of course stretch however it benefits you, but remember that if you are experiencing agonizing pain, it’s far more likely to be doing harm than it is to be doing good. And don’t worry, the ability to touch your toes—or not—has little to do with your overall well being.