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Biology 202
2003 First Web Paper
On Serendip

Stress, Sports and Performance

Arunjot Singh

Actors, athletes and students all have something in common. They all perform their tasks with varying stress levels. What is this stress that we all talk about? Stress can be defined as a physical, mental or emotional demand, which tends to disturb the homeostasis of the body. Used rather loosely, the term may relate to any kind of pressure, be it due to one's job, schoolwork, marriage, illness or death of a loved one. The common denominator in all of these is change. Loss of familiarity breeds this anxiety with any change being viewed as a "threat".

The issue of anxiety is an important aspect of performance. Whether it is during the tense moments of a championship game or amidst that dreaded History exam, anxiety affects our performance via changes in the body, which can be identified by certain indicators. One misconception though with performing under pressure is that stress always has a negative connotation. Many times, "the stress of competition may cause a negative anxiety in one performer but positive excitement in another" (3). That is why one frequently hears how elite players' thrive under pressure, when most others would crumble.

Stress is an integral part of our lives. "It is a natural byproduct of all our activities" (4). Life is a dynamic process and thus forever changing and stressful. Our body responds to acute stress by a liberation of chemicals. This is known as the fight-or-flight response of the body, which is mediated by adrenaline and other stress hormones, and is comprised of such physiologic changes as increased heart rate and blood pressure, faster breathing, muscle tension, dilated pupils, dry mouth and increased blood sugar. In other words, stress is the state of increased arousal necessary for an organism to defend itself at a time of danger. Alterations of hormones in the body include not only adrenaline, but also substances like testosterone and human growth hormone. Up to a certain point stress is beneficial. We perform with greater energy and increased awareness with the influx of excitatory hormones that release immediate energy (11).

As we all probably know, there is only so much tension one can take. Whether it is constant episodes or chronic stress, either can transform what was beneficial stress into "distress". The stress hormones which are protective initially and liberated for self-preservation may cause damage due to overproduction. This has an effect on the entire metabolism, including the rate at which our cells grow and are repaired as well as the production of the cells in the immune system (1).

The hormonal surge of glucocorticoids released to promote utilization of glucose as well as the conversion of protein and lipids to usable glucose can become detrimental in the long run. One clinical symptom that arises from this hormonal imbalance is an increase in appetite, which in a chronic situation, may lead to obesity (2). Catecholamines also increase blood pressure and repeated spikes of hypertension may promote formation of atherosclerotic plaques, particularly with combination of high cholesterol and lipids can ultimately lead to heart disease and stroke.

The brain of course is a crucial target and neurons exposed to elevated glucocorticoids for long periods of time are known to be adversely affected. Tests have shown that brain cells in rats may shrivel and the dendrite branches, which are used to communicate with other neurons, wither away (2). In particular, the hippocampus, which is implicated in memory and mood, may be damaged by stress and the adrenal steroids.

Advances in medical technology like magnetic resonance imaging (MRI) enable us to develop clear images of specific parts of the brain, which in return allow us to see where exactly stress is affecting the brain. The hippocampus which has glucocorticoid receptors is actually noted to be twelve percent smaller in volume in people with stress disorders. Yet, is stress-linked brain damage permanent? Short-term stress damage appears to be reversible (as per rat experiments) though chronic stress may lead to neuronal loss.

"Sports performance is not simply a product of physiological (for example stress and fitness) and biomechanical (for example technique factors) but psychological factors also play a crucial role in determining performance" a href="#3">(3). However, every athlete has a certain stress level that is needed to optimize his or her game. That bar depends on factors such as past experiences, coping responses and genetics (7). Although psychological preparation is a component that has been often neglected by athletes and coaches alike, studies have shown that mental readiness was felt to be the most significant statistical link with Olympic ranking. Athletes have frequently been quoted to state how the mental aspect is the most important part of one's performance. As Arnold Palmer, a professional golfer suggested that the game is 90% psychological. "The total time spent by the golfer actually swinging and striking the ball during those 72 holes is approximately seven minutes and 30 seconds, leaving 15 hours, 52 minutes and 30 seconds of 'thinking time'" (3). Stress during sports, as in anything else in life, may be acute, episodic or chronic. For the most part in sports, it is episodic, whether during a competitive match between friends, or a championship game. While acute stress may actually act as a challenge, if not harnessed, it can evolve to not only an episodic stressor that can affect one in the long term, but can also hamper one's play.

Interest in researching sports psychology has skyrocketed over the past few years. A myriad of hypotheses have been developed to attempt to clarify the relationship between stress and performance. In 1943, the drive theory was introduced, claiming that an athlete who is appropriately skilled will perform better if their drive to compete is aroused or if they are "psyched up". In 1962, the inverted-U hypothesis was formed on the notion that there is an optimal amount of arousal that an athlete will perform at. However, "if that level of arousal is passed then the level of performance will decrease. The same thing happens when the level of arousal is lower than the optimal level" (9). Though this hypothesis has had much support for many years, it too has fallen out of favor due to its oversimplifacation on a subject as complex as brain and behavior. Other theories that have been proposed like the multidimensional anxiety theory and the catastrophe theory all make their predictions on how anxiety plays a role in one's performance level, but the results remains inconclusive (9).

In recent research, the factor of competitive anxiety has been dissected into two segments -- somatic and cognitive anxiety. Cognitive anxiety is characterized by negative expectations, lack of concentration, and images of failure. Somatic anxiety refers to physiological symptoms such as sweaty hands and tension and other physiologic changes (4). In order to chalk out optimal performance, the precursors of anxiety need to be sought out. The temporal patterning of anxiety, before, during and after competition has been receiving a lot of attention in research.

Developing coping techniques is the most crucial element in balancing stress levels so that they optimize instead of inhibit performance level. Relaxation, visualization/imagery, self-talk, goal setting, motivation, and video review are all examples of systems that can be used by athletes (7). Self-regulation training cultivates one's self-confidence and attention control levels. Goal setting is another important system as making realistic short-term goals prevents one from getting overwhelmed, which can result in loss of focus. Having these realistic expectations is the only way one can eventually reach one's long-term goals.

Anxiety control is another technique that is obtained through muscle relaxation exercises as well as mental relaxation through modalities such as meditation or listening to music. Practice for perfection is necessary but as we talk about anxiety control, too much practice can actually lead to overpressure which obviously leads to anxiety beyond the optimal level necessary for the given task. In addition, self-doubts regarding one's performance and a desire to impress others will create a high level of anxiety which leads to "choking" as the athletes' focus on the game is lost as is his/her physical control (6). Athletes that maintain a proper combination of honing their physical skills and developing their mental game are able to adapt to any unfamiliar situation/circumstance that they encounter. As an Olympic champion stated: "My fingers and feet were damp and freezing cold. I felt weak, my breath was short and I felt a slight constriction in my throat... I just wanted to get the whole thing done with. The waiting was agony, but my mind conditioned through long training and experience warned 'wait to warm up! Wait! Wait!'" (11). According to research, elite athletes use these "equalizing" techniques in some combination before, during, and after competition, and this gives them the greatest chance to thrive, even when the game is on the line (5).

A certain level of stress is needed for optimal performance. Too little stress expresses itself in feelings of boredom and not being challenged. "What is becoming increasingly clear... that competitive stress does not necessarily impair performance and can in certain circumstances enhance it" (3). At an optimum level of stress one gets the benefits of alertness and activation that improves performance. Even while making such statements, it is important to realize that there is currently no conclusive evidence except for the fact that stress and anxiety do have an influence in performance.

The surge of interest devoted to this specialized arena reflects how our society breeds competition, not just in sports, but in every aspect of life and at every age. How can I get that edge over the person next to me? That is the mantra by which we are motivated to improve ourselves. Though much progress has been made in this region of neurobiological science, we cannot understand enough to come up with more than an idea of how the brain deals with stress when related to performance. We still have so many unanswered questions regarding the brain and its behavior that we are unable to unravel many of these mysteries though we continue to make educated guesses.


1)McEwen, Bruce. "The Neurobiology and Neuroendocrinology of Stress"
Psychiatric Clinics of North America. 2002 June.

2) New Studies of Human Brains Show Stress May Shrink Neurons , by Robert Sapolsky

3)Jones, Graham. Stress and Performance in Sport. New York: John Wiley and Sons, 1990.

4)Herbert, John. "Stress, the Brain and Mental Illness." BMJ. 30 August 1997: 530-535.

5) Peforming Your Best When it Counts the Most , by Kyle Kepler

6) Choking in Big Competitions , by Kaori Araki

7) The Online Journal of Sports Psychology ,

8) The Mental Edge , by Sandy Dupcak

9) Competitive Anxiety , by Brian Mackenzie

10)Nelson, Charles. The Effects of Early Adversity on Neurobehavioral Development. London: Lawrence Erlbaum Associates, 2000.

11)Neufeld, Richard. Advances in the Investigation of Psychological Stress. New York:Wiley and Sons, 1989.

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