Stress Reactivity in Sport

Although  ubiquitous  in  life,  stress  is  rather  difficult to define. Stress reactivity is a dynamic process involving  context-dependent,  interactive  factors subject to personal interpretation that dictate subsequent  individual  response  patterns.  Stress  is  an extremely  influential  element  of  any  engagement in  sport  or  exercise  participation.  The  present entry  provides  an  overview  of  stress.  It  discusses each  individual  stage  of  the  stress  process  (while giving  particular  emphasis  to  the  critical  role  of cognition  and  appraisal)  and  explores  the  evolution of key theories addressing the effects of stress on all performance with an especial eye to sporting pursuits.

Overview

Despite  the  universal  nature  of  stress  and  its  evident  effect  on  all  of  human  performance,  a  fully comprehensive  understanding  of  its  fundamental nature  still  remains  elusive.  Decades  of  research in  both  psychology  in  general  and  sport  psychology  (SP)  in  particular  fail  to  fully  explain why  stress  provides  the  impetus  for  outstanding physical  achievement  in  some  individuals,  while debilitating  others  to  the  extent  of  spectacular  failure  regardless  their  level  of  preparedness. Notwithstanding  the  continued  debate  regarding an appropriate operational definition, much headway  has  been  made  to  answer  why  humans  vary so widely in their responses to stress, particularly in the realm of sport. One of the clearest explanations  of  this  phenomenon  has  been  provided  by Charles Spielberger.

Spielberger  envisaged  a  three-stage  concept regarding the stress process. The first stage is constituted by the presence of a stressor; the second, the  appraisal  to  what  degree  said  stressor  represents a threat; and, finally, the third comprises the level of state anxiety (SA) prompted by the extent to which the stressor was then judged to be threatening. Spielberger subsequently proposed that athletes’  (re)action  patterns  were  dependent  on  this induced  level  of  anxiety.  Each  of  these  stages  is herein examined in greater detail.

Stressors

Stressors  are  conditions  that  constitute  an objective  physical  or  psychological  threat.  As stress is a biopsychosocial phenomenon, stressors can  emerge  from  any  of  these  biological,  psychological,  or  social  factors.  Biological  stressors are  those  that  test  the  physiological  adaptability of  the  athlete.  The  key  physiological  stressors are  the  adaptations  the  human  body  experiences as  the  results  of  undergoing  the  physical  activity (PA) associated with sport and exercise participation (i.e., pulmonary and cardiac efficiency, skeletal muscle development). Examples of biological stressors outside of the body include extreme temperatures, intense noise, high altitudes, and so on. Psychological  stressors,  on  the  other  hand,  exercise their most profound effect on the performer’s cognitive capacities. Mental fatigue (exhaustion), worry  (suffering  from  disturbing  thoughts),  and competitive  anxiety  (the  predilection  to  interpret competitive  situations  as  threatening)  comprise typically   experienced   forms   of   psychological stress.  Social  stressors  are  those  pressures  that athletes  perceive  to  be  placed  upon  them  by  the sport  community  or  society  as  a  whole.  Athletes subject to social stress can suffer from body image issues,  pressure  to  return  to  training  or  competition after injury (with insufficient recovery time), as  well  as  unrealistic  expectations  (such  as  the pursuit  of  perfection)  from  coaches,  trainers, teammates,  supporters,  or  their  country  (at  the elite  international  level).  There  are  stressors  that impact  the  athlete  via  all  three  channels  such  as overtraining—a phenomenon whereby the volume and  intensity  of  an  individual’s  exercise  surpass the person’s ability to recover (physically and psychologically) that then consequently hinders their progress (causing great concern in the athlete and support staff).

It  is  critical  to  remember,  however,  that  each of  these  so-called  stressors  merely  possesses  the potential to induce change in the athlete. With the exception  of  the  very  extremes  of  environmental stress, a stressor, almost independent of its origin, only  exercises  an  effect  if  the  athlete  perceives  it as  stressful  or  threatening.  The  following  section addresses  this  crucial  role  of  appraisal  in  stress reactivity.

The Importance of Appraisal

A  stress  reaction  generally  does  not  take  place unless appraisal has first occurred. There are any number  of  potential  stressors  continually  present within both the environment and the athlete himself  or  herself.  A  stress  reaction  is  triggered  only when  one  such  stressor  or  several  are  interpreted as threatening to an athlete’s goal fulfillment.

Not  only  is  such  cognitive  assessment  critical because it initiates the stress process, but appraisal is  also  crucial  because  it  regulates  the  severity of  the  stress  reaction.  Therefore,  the  judgment of  whether  or  not  (as  well  as  to  what  degree)  a stressor  is  “stressing”  dictates  the  reactivity  of several  objective  and  subjective  states  within  the athlete that forthwith influence performance.

Such  changes  are  referred  to  as  SA,  the  emotional reaction to an immediate, specific perceived threat (thus subject to fluctuations over time). SA is not to be confused with trait anxiety (TA), the more  stable,  personality-based  tendency  (or  frequency) to perceive stimuli as dangerous. TA does, however, mediate SA levels, as higher TA leads to elevated  SA,  which  some  athletes  view  as  a  hindrance  to  successful  performance.  SA  is  the  final product of the stress reaction and its effects on the objective  and  subjective  states  of  the  athlete  are explained next.

Induced Anxiety (Experience of Threat)

Objective and Subjective Changes

Significant   objective   changes   take   place throughout   the   athlete’s   physiological   system during  stressful  events.  Typical  physical  reactions include  increases  in  perspiration,  respiration  (R) rate,  muscle  tension,  pupil  dilation,  heart  rate (HR) and blood pressure (BP) elevations as well as accompanying decreases in food consumption and digestive rate.

The subjective reactions of SA include emotions (or  feelings)  and  cognitions.  Conventional  emotional reactions include nervousness, apprehension, fearfulness,  and  tension.  Each  of  these  emotional reactions is based on the person’s subjective evaluation of their own preparedness to cope with the stress  of  the  situation  and  the  knowledge  that failure to perform will lead to aversive outcomes.

The thoughts that result from a stress reaction are characteristically  adverse  or  unpleasant  in  nature and most often include uneasiness and worry that such undesirable outcomes will come to pass. The following section presents a number of theories of how these physical and psychological changes collectively influence performance, with special reference to sport activity.

Theories of Stress and Performance

Several sport-specific theories regarding stress and performance have evolved from more general psychological  theories;  here  we  will  discuss  each  of the latter major perspectives in turn. Each theory, however,  defines  stress  in  its  own  way,  which  is somewhat understandable as they were established some decades apart. Acknowledging this compilation of decades of research, we begin each with an examination of the stress process as described by Richard Lazarus.

Lazarus’s  explicitly  stated  prerequisites  necessary  for  an  accurate  model  (that  agree  with Spielberger’s  in  many  respects)  are  that  stress is  (a)  a  dynamic  process  that  is  (b)  iterative  and interdependent in nature, (c) composed of unique interactions between an individual athlete and the environment, and is (d) dependent on the athlete’s appraisal of said environment and his or her ability  to  cope  with  the  potential  demands  imposed and perceived. To explain these effects on performance, three explicit theories are considered.

Yerkes–Dodson Inverted-U Hypothesis

In  the  earliest  of  the  three  theories,  Robert Yerkes  and  John  Dodson  proposed  in  1908  that superior performance occurs when stress levels are moderate,  but  as  arousal  levels  reached  extremes (i.e., too high—hyperexcitement or too low—boredom), learning capacity deteriorates in a symmetrical and increasingly drastic fashion. Graphically, such  a  relationship  resembles  an  inverted-U  form (hence  the  theory’s  enduring  name).  However, inspection  of  Yerkes  and  Dodson’s  original  data reveals  many  inconsistencies,  indicating  that  the range  of  arousal  deemed  “moderate”  and  therefore optimal is fairly small.

The  inverted-U  hypothesis,  as  originally  presented,  leaves  much  to  be  desired,  most  critically when  trying  to  predict  performance  outcome. Additionally,  attempting  to  explain  past  performance  using  Yerkes  and  Dodson’s  theory  leads one to deduce that when performance is poor, the performer  is  either  too  aroused  or  insufficiently aroused, but this may not actually be the case.

Individual Zones of Optimal Functioning Model

Yuri Hanin attempted to take the idea of optimal functioning a step further by stating that the most  advantageous  state  of  arousal  is  not  necessarily  “moderate”  but  in  fact  differs  across  individuals. Yuri Hanin’s individual zones of optimal functioning (IZOF) model holds that performance is successful when initial stress levels are within an optimal  zone,  which  is  specific  to  that  individual athlete. If the athlete’s stress level falls outside his or  her  personal  range,  performance  degrades.  In contrast to the Yerkes–Dodson inverted-U hypothesis,  which  implies  that  stress  levels  should  be ubiquitously  moderate  for  optimal  performance, Hanin’s model does not specify what level is ideal. The  optimal  level  (whether  high,  moderate,  or low) depends solely on the individual performer.

The Dynamic Adaptability Model

Peter  A.  Hancock  and  J.  S.  Warm’s  dynamic adaptability   model   integrates   and   synthesizes aspects  of  the  aforementioned  theories.  Much like  Spielberger’s  conceptualization,  the  theory  is founded on a trinity of stress, namely input, adaptation, and output. Input encapsulates the physical sources  of  stress  in  the  environment.  Adaptation consists of physiological and psychological adaptations to this input and so reflects the appraisal process.  Output  denotes  the  change  in  goal-directed response  efficiency.  In  sport,  this  latter  selection would represent efficiency on any particular task-related  performance.  When  represented  graphically,  the  dynamic  adaptability  model  resembles an extended-U shape, which retains the inverted-U notion  that  performance  deteriorates  quickly  at the extremes of stress. However, here there is also an  optimum  range  between  the  extremes,  which yields  a  successful  plateau  of  stable  performance. The extended-U also incorporates the IZOF model’s  view  that  the  optimum  range  is  based  on  the individualistic nature of each performer. Hancock and  Warm’s  theory  further  contends  that  the extent  of  the  optimum  range  not  only  is  subject to the athlete’s physical and psychological capacities  for  adaptation  to  stress  but  is  also  crucially contingent upon the recognition that the task itself is the major proximal source of stress. Collectively, these conceptions serve to describe stress reactivity and provide a theoretical and quantitative basis to understand  how  athletes  respond  to  the  stresses that their sports impose upon them.

References:

  1. Gill, D. L. (1994). A sport and exercise psychology perspective on stress. Quest, 46, 20–27.
  2. Hancock, P. A., & Ganey, H. C. N. (2003). From the inverted-U to the extended-U: The evolution of a law of psychology. Journal of Human Performance in Extreme Environments, 7(1), 5–14.
  3. Hancock, P. A., & Warm, J. S. (1989). A dynamic model of stress and sustained attention. Human Factors, 31, 519–537.
  4. Hanin, Y. L. (2007). Emotions and athletic performance: Individual zones of optimal functioning model. In D. Smith & M. Bar-Eli (Eds.), Essential readings in sport and exercise psychology (pp. 55–73). Champaign, IL: Human Kinetics.
  5. Spielberger, C. D. (1989). Stress and anxiety in sports. In D. Hackfort & C. D. Spielberger (Eds.), Anxiety in sports: An international perspective (pp. 3–20).New York: Hemisphere.

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