Excerpted from The Athlete’s Gut: The Inside Science of Digestion, Nutrition, and Stomach Distress by Dr. Patrick Wilson.
Stress and Anxiety
Pre-game nerves. Race-day jitters. Unabating thoughts of choking. A thumping heart. These are all manifestations of competition stress and anxiety, and many athletes—from recreational ballers to Olympic champions—experience these symptoms regularly. The effects of competition anxiety undoubtedly extend to the gut. As an example, one of the more common symptoms associated with stressful competition (or anxiety from a job interview, first date, etc.) is butterflies in the stomach, a ticklish or fluttering feeling in the abdomen. (The exact physiology behind this fluttering is a mystery, but it may have to do with changes in gut blood flow and nervous system activity.) Athletes nervous about an upcoming game or race are known to be stricken by other gut symptoms like nausea/vomiting, abdominal cramping, and unrelenting urges to use the privy.
While the gut is often thought of as being distinctly separate from the brain, the connections between these two parts of your body run deep. As I detailed in Chapter 1, your gut is home to between 100 million and 600 million neurons, which is one reason it’s referred to by many scientists as the body’s “second brain.” These connections allow important information about what’s happening in your gut to be relayed to your central nervous system. Likewise, information flowing in the opposite direction—from your central nervous system to your gut—allows your body to prioritize how resources such as blood and oxygen are utilized during times of stress. Like any elegant system, your gut-brain connection is prone to glitches. Experiencing too much stress, excessive anxiety, or a traumatic event can muck up this intricate system.
Stress is a fundamental, inevitable part of life. Yet for many of us, the word stress evokes mostly negative connotations. It’s true that too much stress can be harmful to your health and performance, but it’s important to remember that stress is your body’s response to any demand placed on it. This generalized, purposefully vague definition of stress was first proposed by Hans Selye, an Austro-Hungarian endocrinologist considered to be the father of the modern biomedical stress concept.4 Selye’s thoughts on stress can be succinctly summarized with an oft-used quote from his thousand-plus-page doorstopper, Stress in Health and Disease:
“Stress is not something to be avoided. Indeed, it cannot be avoided, since just staying alive creates some demand for life-maintaining energy. Even when man is asleep, his heart, respiratory apparatus, digestive tract, nervous system and other organs must continue to function. Complete freedom from stress can be expected only after death.”5
As with most sweeping theories, not everyone agrees with Selye’s take that stress is best viewed as a nonspecific response.4 Regardless, there is universal agreement that stress is a necessary part of life. What’s also true is that persistent elevations in certain types of stress are damaging to health and performance. For example, heightened psychological stress in the workplace or stress that’s a result of a traumatic life event have been linked to ailments such as stroke, type 2 diabetes, and obesity.6–8
In athletes, the acute psychological stress that bubbles up before and during competition is ubiquitous but doesn’t necessarily have a predictable relationship with performance. Among other reasons, this is because of differences in how stress is defined and measured in studies as well as the variability in how individual athletes appraise the manifestations of stress. As an example, one athlete might perceive a pre-game elevation in heart rate as a positive signal that their body is prepping itself for the challenge to come, while another athlete may view this same response as a disturbing lack of control over their bodily functions.
Despite the inconsistent associations between acute competition-related stress and performance, long-term elevations of stress—especially if they’re perceived by an athlete to be negative—are dependably linked with injuries and overreaching syndromes.9 These connections are so reliable that in 2006 the American College of Sports Medicine (in conjunction with several other medical organizations) published a consensus paper with the following statement about the impact of stress on injury:
“Personality factors (e.g., introversion/extroversion, self-esteem, perfectionism) and other psychological factors (e.g., a supportive social network, coping resources, high achievement motivation) alone do not reliably predict athletic injury risk. . . . However, there has been a consistently demonstrated relationship between one psychological factor—stress—and athletic injury risk.”10
So even though direct relationships between stress and athletic performance are rather unpredictable, it’s obvious that an injured or sick athlete is one who can’t perform at her peak. Thus, it behooves coaches and practitioners to pay close attention to sources of stress in their athletes’ lives.
For more on stress, anxiety, and their effects on the athlete’s gut, order a copy of The Athletes’s Gut by Dr. Patrick Wilson.
4. G. Fink, “Stress: Concepts, Definition and History,” in Reference Module in Neuroscience and Biobehavioral Psychology, ed. J. Stein (Amsterdam: Elsevier, 2017).
5. H. Selye, Stress in Health and Disease (Oxford: Butterworth-Heinemann, 1976), 15.
6. J. Booth et al., “Evidence of Perceived Psychosocial Stress as a Risk Factor for Stroke in Adults: A Meta-Analysis,” BMC Neurology 15 (2015): 233, https://doi.org/10.1186/s12883-015-0456-4.
7. S. J. Kelly and M. Ismail, “Stress and Type 2 Diabetes: A Review of How Stress Contributes to the Development of Type 2 Diabetes,” Annual Review of Public Health 36 (2015): 441–462.
8. N. Bergmann, F. Gyntelberg, and J. Faber, “The Appraisal of Chronic Stress and the Devlopment of the Metabolic Syndrome: A Systematic Review of Prospective Cohort Studies,” Endocrine Connections 3, no. 2 (2014): R55–R80.
9. A. Junge, “The Influence of Psychological Factors on Sports Injuries. Review of the Literature,” American Journal of Sports Medicine 28, no. 5 supplement (2000): 10–15.
10. American College of Sports Medicine et al., “Psychological Issues Related to Injury in Athletes and the Team Physician: A Consensus Statement,” Medicine and Science in Sports and Exercise 38, no. 11 (2006): 2030–2034.
The Athlete’s Gut: The Inside Science of Digestion, Nutrition, and Stomach Distress is an in-depth look at the GI system that offers a much-needed resource for troubleshooting GI problems.