Know pain: understanding the neural underpinnings of pain in endurance sports
One of the pillars of mental training is learning how to be comfortable being uncomfortable. In fact, this is an aspect of the yoga practice that resonates with the athlete within me. In yoga, the Asanas (physical postures) we form are not always comfortable. That mild discomfort brings us in to the present as we are forced to breathe through it. As any athlete knows, however, there’s a difference between positive pain and negative pain.
During my ballet years, pain was just a part of the game; a lot of it was positive (soreness as muscles strengthened), but too much of it was negative. I commonly put lidocaine on my blistered and bloodied toes before putting on my pointe shoes and going on stage. We used to slide the tops of our feet under a sofa and then slowly straighten our legs, forcing our arches to stretch. This pain went beyond the threshold of uncomfortable, but somehow I was able to perform through it. So how is that?
Well, it turns out that your mindset can affect how you perceive pain. For a long time, psychologists theorized that mental techniques such as visualization, positive self-talk, or cognitive self-regulation, could alter one’s experience of pain. In 2015, neuroscientists discovered neural pathways that may help explain how shifts in mindset contribute to our experience of pain.
Nociceptive pain (the category most sports-related pain falls into) is caused by inflammation, chemical changes or physical trauma that damages the nociceptive nerve fibers. This type of pain triggers a signature pattern of activity in the brain, involving the somatosensory cortex and the anterior cingulate cortex.
The notable discovery in a PLOS Biology study, however, is that there also exists a separate and distinct pain pathway that is mediated by self-regulation of pain. When subjects engaged in self-talk and visualization to “regulate-up” or “regulate-down” the pain (i.e. talk themselves into experiencing the heat stimulus as hotter/more painful or cooler/less painful than it actually was), their brain revealed activation of this new pathway. While this may not seem remarkable, it actually is quite fascinating when you consider that one’s perception of pain as being better or worse than it actually is may, in fact, have a concrete neuronal response that in turn affects the primary pain pathway and, ultimately, your experience of that pain.
This may be a reach, but let's link in one more fascinating study out of the University of Pennsylvania. Researchers sought to understand how the brain handles both hunger and pain simultaneously (side note: two states endurance athletes know well). Interestingly, they found that inflammatory pain, but not acute pain, is weakened in response to hunger. Furthermore, this attenuated response is caused by a super tiny sub-population of neurons (300 to be exact). This makes sense from a survival standpoint: Animals need to be able to prioritize finding food and eating, even if they’re injured. During endurance races, the body essentially enters a state of hunger, correct? Yes, the athlete fuels the body; and no, the athlete is not focused on hunger as much as it’s focused on continuing to move. But, the energy demands far outweigh the caloric intake, so the body is essentially starving. What if this hunger state triggers the brain to attenuate the pain response? Could that help explain how so many endurance athletes are able to get through a race even when their body is in so much pain? Is there a link between adrenaline, hunger, and the pain response? It’s entirely too early to project these findings on to human behavior (much less athletic behavior), but it’s definitely a fun thought experiment!