By Ryan Woolley
Recently, I've felt stressed. A role change at work has forced me into overload. As I line up each day, the break shot of my own cognitive game of billiards splits my attention, causing me to feel frantic and hurried. In heightened moments, my eyes widen, I fumble through conversations, and my body language becomes less intentional. And, something else happens that I'm less attuned to… My stomach begins to move into a frenzy of contractions, causing an increase in its production of digestive acid. The sandwich that I inhaled earlier also comes to a standstill as my gut begins to adjust to the signals that it's receiving from my brain. Some of these signals are originating from my facial expressions. That crooked brow that I failed to hide in a team meeting earlier doesn't exist in a vacuum; it's picked up and read internally by my body's second brain - the Enteric Nervous System (ENS).
A collection of some 500 million neurons embedded in the lining of the gastrointestinal system, the ENS is just one component that assists in the bi-directional flow between the gut and the emotional and cognitive centers of the brain. Combined with signals generated from the body's adaptive responses to stress (the Hypothalamic-Pituitary-Adrenal axis), the immune system, and autonomic nervous system, the gut-brain axis (GBA) comprises a complex rhetoric that occurs continually between the body and mind (insert kitschy mind-body connection quote here). Extensive research into the GBA has discovered that our emotional state can directly impact the health of the gut. And, because this is a two-way street, the state of our gut can also have a profound impact on our emotional health and ability to process stressful events.
Previously, in Check Yourself Before You Wreck Yourself…
In article one of the "Check Yourself" series, while using Jackson Brown's "Running on Empty" as a metaphor, I attempted to unpack some of the vague associations that endurance athletes can have with Over Training Syndrome (OTS). I had locked in on a definition (Kreher, 2016) that described OTS as, "… an extreme condition of maladapted physiology" where the hormonal, immunologic, neurologic, and psychologic systems fail to cope with and respond adequately to excessive exercise. With long stretches of high volume training paired with rest, OTS can surface as debilitating staleness, a loss of appetite, diminished libido, and heart arrhythmia. As a key piece to the OTS puzzle, the HPA (Hypothalamic-Pituitary-Adrenal) axis was pulled into the conversation: Cadegiani and Kater (2017) found that athletes experiencing OTS have blunted hormonal responses to exercise and stress compared to healthy athletes. Continual exposure to stress generated by seemingly excessive amounts of exercise can cause some of the body's core stress-response systems to become less sensitive to their surroundings. Despite uncovering some useful information, article one left me wondering - are there clear determinants of OTS? If so, how much training is too much? Yiannis Kouros ran 1,000 miles in under ten-and-a-half days. His competitive career as an ultra runner spans well over twenty years. Has he ever battled OTS?
In the second article, I reflected on what I had learned from Gary Moller, a Health Practitioner based in Wellington, New Zealand. We used a Hair Tissue Mineral Analysis test to uncover the state of basic nutritional building blocks in my system. Through Gary's assessment, we discovered that I had “a little rust under the chassis.” In neglecting to keep up with the nutritional demands that endurance exercise can place on the body, cracks had begun to appear - surfacing as heart arrhythmia, tendonitis, and poor recovery. Depleted levels of key antioxidant derivatives, such as copper, manganese, and selenium showed a system that was struggling to heal itself and remain in balance.
As the final installment of the "Check Yourself Before you Wreck Yourself" series, this article will speak to the deep, complex connection that exists between our physical and emotional health. This is not an article on how to train better, nor is it an article on emotional wellbeing. Rather, my intention is to explore the connection that exists between our physical and emotional selves, and how an understanding of this relationship can allow us to be better runners, hikers, or wanderers.
Part Seven: It Really Does Take Guts
The two-way conversation occurring between the gut and the brain involves insignificant input from the gut's microbiota. This invisible crowd of contributors comprises a diverse array of bacteria that communicate with the central nervous system through neuroendocrine and metabolic pathways (Carabotti, Scirocco, Maselli & Severi, 2015). This connection ensures that the body and mind are constantly communicating and collectively adapting to external stressors. On a fundamental level, it ensures that each survives an environmental onslaught (perceived or actual); though the microbiome needs us as a host, we most certainly need these roommates to help us respond to environmental cues while also alerting us of anything going wrong within the gut. Acknowledging this connection is crucial, not only in considering how stress can impact the absorption of macro- and micro-nutrients; it can also determine another means to which we can preserve our emotional and cognitive health.
Part Eight: Chatter
The central nervous system has a direct line of communication to the gut through parasympathetic and sympathetic nervous systems. The tone of the parasympathetic nervous system is most prevalent when we are in a state of calm and is responsible for the body's rest and digestion response. In this state, the PNS is able to stimulate the enteric nervous system to effectively break down and absorb the contents that we send to the gut. Conversely, during periods of stress, as it prepares the body to fight or flee, the sympathetic nervous system stalls this process while inhibiting the work of the enteric nervous system. As it diverts blood to the heart, lungs, and the musculoskeletal system, the sympathetic nervous system's response also causes a change in the size and quality of mucus secretion (Foster, Rinaman & Cryan, 2017). Mucus serves to facilitate the movement of food through the stomach while forming a protective layer over the lining of the gut. In this regard, exposure to acute and chronic stress can alter both the quality and quantity of calories consumed (Foster, Rinaman, & Cryan, 2017). Short and long term exposure to stress can also have a direct impact on the gut's microbiota and their contribution to digestion (Carabotti, et al., 2015). After receiving a call-to-action by the body's stress response, using the gut-brain-axis, our microbiome can't help but respond in its own way.
Research has shown that changes to the gut microbiota can influence indicators of emotional and cognitive health. Alterations through diet and exposure to turmoil influence how we respond to stressful events by messing with the set point of the HPA axis. It looks like we're dealing with both sides of the same coin, here - in causing some long term changes in the gut-brain-axis stress can beget… stress. These alterations can have a profound impact on the brain. While discussing the influence of stress of the gut-brain axis, Foster, Rinaman, and Cryan (2017) state that the character of the gut's microbiome affects the structure and function of the amygdala, a region of the brain critical for emotional learning and social behavior. In this sense, microbiota are critical in the moderation of behavioral and physiological responses to stress.
This communication system starts to generate news at birth. Coupled with genetic disposition, alterations in microbiome composition early in life - through infection, stress exposure, or other environmental influences - can result in the development of deeper circuitry that influence how we respond to stressful events later in life. Research has connected these changes to symptoms of anxiety and depression. In likening the conversation along the gut-brain-axis to a theatre play, Mayer (2016) mentions that the gut cells of people who are chronically angry or anxious can "adapt over time to accommodate the stage directions". In true adaptive form, the system learns how to finely tune its response to the environment. Though, this occurs to the detriment of our psychological well being. Discovering the long term implications of an altered gut-brain-axis brings to mind the brief anecdotal accounts of over training syndrome (OTS) covered earlier in this series. Considering the interplay between the body's stress response and the gut's microbiome, it becomes easy to correlate the role that the gut-brain axis plays - both in allowing a competitive endurance athlete to become more susceptible to OTS while also causing a return-to-health to be a long, arduous process. Altered gut health may be a core mediator in the development of symptoms associated with overtraining syndrome.
Part Nine: Ideas
I will happily admit that these articles have allowed me to muddle my way through a fairly complicated set of personal experiences within my running life. And, though I don't claim to have striking evidence for every finding or conclusion within the content, I do feel confident in the process of exploring topics such as these - topics that feel vague and misunderstood. Ultimately, my goal is to pass on tidbits of information that others can use to hopefully express the best parts of themselves through running and exploration. With that, I would like to wrap up this series with some ideas:
Try to avoid being a weekend warrior. Though the thought seems ideal for those who have a crammed working week, demanding a big output from the body during isolated weekend running adventures could do more harm than good. Consistent, progressive loads of exercise allow the body to develop and strengthen the means to buffer the oxidative stress of endurance training. Taking on a large dose of road or trail time on a Saturday could provide you with all of the stress without the buffering, causing the body to take longer to bounce back. To avoid this, build in smaller spurts of exercise intermittently during the week. We've all got 15 minutes, right? Use that time to chase the dog around the yard.
Progression is key. Similar to the point above - be patient in adding additional cumulative loads of exercise. Believe me - I want the trail running world to be my oyster at the flip of a switch. But, sometimes, I need to cool my jets. The body needs time to adjust and reset in both micro and macro phases of training. Use volume and intensity as different levers to pull here. Be careful increasing these at the same time.
You can add salt to your soup. But, you can't remove it. Unless you’re a deity of health and wellness, you've absolutely had periods where you've felt stale and overworked. During days such as these, it may seem reflexive to continue with a prescribed training plan. But, instead, consider providing your body with a dose of rest. Additionally, think about how you can treat your microbiome with foods that are going to allow it to rebuild. If you're tired, your body is likely in a state of underlying stress.
Discover how your lifestyle is impacting your health status. Submit for a Hair Tissue Mineral Analysis (I purchased mine from here). Similarly, ask your PCP about a vitamin and mineral blood test. There are a variety of testing protocols out there - do your research first. Some may be more valid than others. After you've received your results, connect with a health and wellness professional who knows how to interpret them. Gary Moller accepts virtual appointments and is at the forefront of Hair Tissue Mineral Analysis in New Zealand. Reach out to me if you need someone to interpret the accent...
When it comes to diet, prioritize quality over quantity. Sounds simple, doesn’t it? But, often I hear of athletes prioritizing the replacement of calories over vitamins and minerals. I’ve been there - in response to ramping up volume, I’ve been known to put away an extra pint or two of Ben & Jerrys’ “Half Baked”; and I don’t regret that. What the body needs, however, is the addition of foods that are guaranteed to nourish the system and aid in the body’s ability to withstand stress. So, at the height of the season, think about incorporating extra nuts and seeds, dried fruits, bone broth, dietary fiber, and antioxidant-rich foods. With this approach, the addition of extra calories will look after itself.
Look after your gut. The gut's microbiome loves dietary fiber. Fermentation of indigestible food leftovers in the gut helps in the proliferation of beneficial bacteria that produce short chain fatty acids. These contribute positively to other systems in the body. Butyrate, for example, can induce the breakdown of colon cancer cells and has a beneficial effect on glucose and energy homeostasis (Valdes, et al., 2018). Acetate is also used in cholesterol metabolism and may play a role in appetite regulation. Mayer (2016) suggests treating your gut microbiome as a farm and your microbiota as your own personal farm animals - consider what you're feeding them, and what impact it could have on the whole system. In general, reduce the amount of animal fat, sugar, and additive-ridden foods. Lastly, shop around for a decent probiotic supplement. Your microbiome farm will thank you.
Think about where you experience stress in your life, and consider how to minimize your exposure to it (I'm sure that we all try to do this anyway). In combination with the paragraph above - avoid eating while stressed, angry, or sad. Exposure to such stressors is going to throw the gut-brain axis out of whack, limiting the gut's ability to effectively work with the food that you're eating. Eating while stressed can be bad for your gut and your brain (Mayer, 2016).
Above all, you owe it to your health to trust your gut (see what I did there?).
About the Author
Raised in Hawke's Bay, New Zealand, Ryan Woolley is a distance runner with a passion for ultra and mountain events. He also has a love for guitar, banjo, drawing, and Quentin Tarantino films. He currently resides in Colorado with his partner, Roni, and dog, Henry.
References:
Carabotti, M., Scirocco, A., Maselli, M. A. & Severi, C. (2015). The gut-brain axis: interactions between enteric microbiota, central, and enteric nervous systems. Annals of Gastroenterology. 28(2), 203-209.
Foster, J. A., Rinaman, L. & Cryan, J. F. (2017). Stress & the gut-brain axis: Regulation by the microbiome. Neurobiology of Stress. 7, 124-136. https://doi.org/10.1016/j.ynstr.2017.03.001
Mayer, E. (2016). The Mind-Gut Connection: How the hidden conversation within our bodies impacts our mood, our choices, and our overall health. HarperCollins.
Valdes, A. M. (2018). The role of gut microbiota in nutrition and health. Science and Politics of Nutrition. 361. doi: https://doi.org/10.1136/bmj.k2179