Performing Under Pressure: The Sympathetic vs Parasympathetic Balance
Sport is Beyond Physical:
As athletes we spend countless hours preparing our muscles, bones, and more to be ready for the high demands of training and racing. We carefully think about what food we put in our bodies for proper body composition, we aim to run on soft surfaces to protect our bones from unnecessary stress, and we do strength workouts to develop lean muscle mass. Just about every action in our daily lives has an underlying thought on how it will physically affect our body. However success is sport is far more vast than just the musculoskeletal system, the most foundational system that dictates all others is the nervous system. We often wonder why we or others under perform on race day, and while it could be the former, it is more often the later.
The Nervous System:
Every athletes will agree that the mind plays a tremendous roll is sport beyond just the body. Variables like motivation, confidence, or race skills all play a tremendous roll in success, however this post is about a more about the subconscious portion, the sympathetic/parasympathetic balance deeply rooted in the nervous system. Breaking it down, the nervous system has two branches, the central nervous system, consisting of the brain and spinal cord, as well as the peripheral nervous system. Next, the peripheral nervous system is broken up into the somatic nervous system, its primary role being the movement of skeletal muscle under conscious control, on the other hand there the autonomic nervous system is more about subconsciously regulating balance and other functions in the body. FINALLY, the autonomic nervous system is broken up into the sympathetic nervous system and the parasympathetic nervous system, which is the focus in this post.
Fight or Flight:
The sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS) work together in a yin-yang fashion, based on the perception of threat in an environment. The SNS drives the “Fight or Flight” response, while the PNS drives the “Rest and Digest” response. Under a threatening environment, the SNS will increase heart rate and breathing rate to provide more oxygen to muscles, lower electrical activation threshold in muscles, inhibit function in the digestive and immune systems, and release epinephrine, aka adrenaline. It is a primal animal instinct so deeply rooted in the nervous system that it can be seen in animals across multiple species. It is the response one would have if being chased by a bear! We are all familiar with this response, however it is not too often that we get chased by a bear anymore! You do feel it when you speed past a hidden cop, then stare in your rear view mirror anxiously waiting to see if the lights flash on, or when you see someone out in public whom you have no desire in talk with, finally, you have likely experienced this feeling in the moments leading up to a big race, one that you have been thinking about for weeks!
Rest and Digest:
On the other hand, the parasympathetic nervous system relaxes the body. Without a pending threat, the PNS increases digestive function, lowers breathing and heart rate, assists with sleeping, maintains homeostasis in many systems, and releases acetylcholine, a neurotransmitter with multiple functions in the body. Using our primal animal analogy, think of the state of an animal relaxing safely in its cave, free of any bears! In a real world setting it’s a quite similar situation, its what you perceive at the end of a long day, relaxing in your bed, again, free of any bears. The PNS is also responsible for calming the body after a sympathetic response. Think of when you’re running on the trails and you hear a rustle in the bushes, immediately after you jump in a panic you notice it is only a squirrel and your PNS then takes over and brings you back to baseline. It is important to note that in every situation, it is the PERCEPTION of threat that governs the sympathetic/parasympathetic response. It is also important to note that the sympathetic nervous system and parasympathetic nervous system act inversely to each other, so if you are MORE parasympathetic then you are naturally LESS sympathetic, and vice versa. These two principles will be your key to obtaining more success in sport and work.
The Swing:
Coming back to another bear reference that we are growing so fond of, the grizzly bear is notorious for being extremely polarized in its sympathetic/parasympathetic balance. The grizzly bear can normally only be seen in two ways, extremely aggressive or super chill. If you approach a grizzly bear when its cub is around, the bear will have tremendous sympathetic innervation as its “fight or flight” response dramatically takes over (and yours as well!). In a different scenario the grizzly bear is known to hibernate for months as a time, driven by tremendous parasympathetic innervation, the ultimate “rest and digest” state. A bears ability to swing between extremely sympathetic to extremely parasympathetic is seen in a lesser extent in all animals including humans. Imagine this sympathetic/parasympathetic swing as a literal playground swing where the further you pull/push it to once side, the further it will launch to the opposite once let go. (However the flaw in the analogy is that it swing will likely STAY on the alternate side and slowly return to the center. It can also be imagined like a bow and arrow launching an arrow or a slingshot)
Collapse Under Pressure:
This swing can be seen in a college kid cramming for finals or a lawyer frantically trying to finish a big case before deadline. In both scenarios there is a high perception of threat thus a high sympathetic response. However there is an end in sight, and once the finals or the case is over, the individual will “swing” from a very sympathetic state to a very parasympathetic state, likely feeling extremely tired and even potentially getting sick now that the body has finally let down its defense. Athletes have often seen this sympathetic/parasympathetic swing when certain athletes (maybe oneself) always race poor when it matters most, or “crumble under pressure”. Often this failure is not caused from anything in training, but it is caused from the days or weeks leading up of being highly sympathetic. This is especially the case if the athlete reports how well training was going leading up (because obviously it will go well with high amounts of adrenaline and sympathetic innervation)! However come race day the parasympathetic nervous system takes over for one of two reasons, either the sympathetic system is finally fatigued from being activated for so long, or the feeling of “race day is finally here” lowers the guard and thus swings to the parasympathetic side. Making it to race day isn’t hard nor an accomplishment, it’s about making it to the finish line on race day with a respectable performance, however it is not often seen because of this phenomenon. No matter how fit an athlete is, if their foundational autonomic nervous system is telling their body to rest or to hibernate like a bear, they will not perform. It is the feeling of being “flat” or “having no spark” that we have all experienced at one time or another. While the fatigue can certainly be physical (and very often so), due to over training and poor taper, very often it is caused by poor sympathetic/parasympathetic balance.
Stuck in the Middle:
In other scenarios people are trapped in a state in the middle, with both minor sympathetic innervation and minor parasympathetic innervation. This is the state of being tired all day, but then being unable to fall asleep at night. Or from athletes standpoint, this is the state of having poor workouts but then going home and being worked up and stimulated about your workouts being poor! This state of having “no swing” is from a constant perception of low level threats. Our threats or pressure could be constant work stress, unpleasant social interactions, or the fear of failure caused by feeling unprepared for a race. The issue in being in this state is that you take the negatives of both systems without the positives. So you have poor recovery, sleep, digestion, as well as poor adrenal response, muscle activation, and stimulation. This state is caused by your sympathetic nervous system being constantly activated subtly by pressure or “threat” that never ceases, thus your parasympathetic nervous system is then always activated in an attempt to balance out the autonomic nervous system. If let unsolved, eventually the body will crumble to an utterly devastating state.
Shift Your Mindset:
The solution to taking advantage of the sympathetic/parasympathetic balance is what I call “reversing the swing”. As stated, typically we subconsciously push ourselves toward a sympathetic state, then launch toward parasympathetic, so reversing the swing is about making an effort to stay in a parasympathetic state then launch toward sympathetic when necessary. While the peripheral nervous system is autonomic and not under conscious control, it is the perception of threat that you can control, so simply adjusting your mindset is one of the best ways to stay in a parasympathetic state. As well as this, the respiratory system is is both innervated somatically and autonomically (or voluntary and involuntary)! Deep breathing has been shown in countless studies across countries to “relax the body” aka shift toward a parasympathetic state. One sensation when we see the swing reversed is “cabin fever” or feeling “stir crazy”. The yin-yang balance of the sympathetic v parasympathetic nervous system will naturally swing to a state of “fight or flight” after extended time in a “rest and digest” state! (If you’re reading this in quarantine during COVID19 you can likely relate!) From an athletes standpoint it is about during workouts without perceiving them as end all be all and especially not getting simulated/frustrated following a poor session. Maintaining a relaxed state, and making an effort to push your “swing” toward parasympathetic allows you to launch toward sympathetic come race day or high intensity workout days. The fight or flight response is a powerful state to be in come race day, and definitely an essential tool to use when trying to accomplish your goals! In addition, recovering from workouts is much improved in a parasympathetic state. So be sure you’re in the right state at the right time!
Invest in the Abstract
It is easy in sport and life to work on the most simple and quantifiable actions, like miles completed and watts achieved, however often the most abstract ones like mindset and the Sympathetic/Parasympathetic Balance could be the piece keeping you from your goals! While often difficult to control the environments we are in, we can certainly control our response to the environment as well as our mindset in them!
Feel free to reach out if you have any feedback or criticism, or want to chat more about my thoughts. Some of these theories are proven across countless studies and others are simply my theories based on the foundational understanding of the physiology and my experience from both racing and coaching. If you enjoyed or feel like this could benefit someone please share and give me a shout out! My instagram is @swimmikerun and email Michael.arishita@gmail.com.
Michael Arishita
