Your body tenses for a reason. The trick is not to overdo it.

When I was in labor, everyone encouraged me to remember to breathe—the OB-GYN, the nurses, my partner, my parents, and anyone else who wandered into the room. As if I—after months of practicing deep breathing to ocean sounds—didn’t already know this. As if I was purposely trying not to breathe, instead of frantically gasping for breath amidst the pain. “You’re fighting the contractions,” someone said. “You’re tensing all over. It’s just going to be more painful if you’re tensing. Give in to the contractions.” Instead of curling inward or grabbing the bedrails until my knuckles turned white, I purposely opened up my body, concentrating on releasing the tension and my breath. When we’re in pain, it’s so much easier to tense our muscles, hunch our shoulders, and scream, but in that instance, I breathed, released, and relaxed. And then the process started all over again when the next contraction hit.

Why is muscle tensing such an automatic reaction to pain if it may also increase discomfort? The answer lies in the fight-flight-fright response: when facing a life-threatening situation our bodily functions, including muscles, hormones, digestion, and reflexes, can shift into a highly reactive state. “What we perceive as tensing is a sudden rise in cardiac output (mostly an increase in heart rate, but also in contractility) which is felt as a rise in blood pressure, combined with a priming of skeletal muscles for action. During these sympathetic responses, skeletal muscles open their blood vessels and begin mobilizing stored glucose, which puts them ‘on edge’, by lowering their threshold for contraction,” says Nathan H. Lents, a professor of molecular biology at John Jay College of the City University of New York. When muscles tense, they can respond quickly if necessary for self-protection. So there are benefits to having the ability to tense up. We don’t only tense when we sense danger though. Tensing is a manifestation of stress, and modern day stressors like work or commuting can lead to chronic tension. Similarly, acute pain and chronic illnesses can heighten the frequency and magnitude of tension. “Pain is initially a protective response but if not controlled it can become destructive and maladaptive in a similar way to being too tense for a prolonged period of time,” says Dr. Lynn Webster, a physician and pain researcher.

Muscle tension can be both helpful and problematic. It may seem counterintuitive for our bodies to act unfavorably, but evolution is an imperfect process. According to Lents, we have glitches throughout our bodies, from genes and proteins to anatomy and physiology. Many of our physical traits are the result of compromises. These glitches don’t have to stop us in our tracks. Deep breathing can help us deal with muscle tension by offering relaxation and a different focal point. “Anxiety and tension increase the level of pain. Deep breaths refocus our attention, clears the mind, and reduces the tension,” Webster says. In general, distractions like deep breathing can alleviate pain by taking our mind off of discomfort. Lents says this can also be achieved at the molecular level by stimulating the same sensory nerve that carries pain with other kinds of stimuli. For example, when we stub a toe, an automatic reaction can be to shake it out or move it around. When we do this, the pain signal can be diluted by the other signals in the same nerve. When we deep breathe, the chest expansion that occurs can be a stimulus that can drown out the pain. “Different things work for different people, but the common thread is that if we consider pain as something competing for our attention, we can do some work to put our focus on other things instead,” says Lents.