In terms of cardiovascular, endocrine and immune responses, acute high-intensity aerobic
exercise stress may be considered as a subcategory of stressful active coping. The
cardiorespiratory responses of both include increases in heart rate, cardiac output,
systolic blood pressure, skeletal muscle vasodilation and oxygen consumption. Neurohormonal
responses include increases in catecholamines as well as elevations in Cortisol under
high but not relatively low sympathetic activation. Immune system responses include
increases in natural killer (NK) cell number and cytotoxicity and suppressor/cytotoxic
lymphocytes as well as decreased proliferative response to mitogens. Task and recovery
periods for both acute psychological stress or exercise show biphasic changes in immune
response such that immune status is negatively impacted during recovery. Chronic life
stressors influence acute cardiovascular, endocrine and immune responses to acute
stressors. In addition, both chronic stress and unusually heavy chronic exercise can
negatively impact immune status. Given impaired immune status following chronic stress
and interactive effects of acute and chronic stressors (e.g. blunted acute NK responses
to acute stressors), it is suggested that these factors may extend the window of vulnerability
for infectious agents to act following acute psychological (e.g. examinations) or
strenuous exercise (competitive athletics) stressors.
Key words
Psychological stress - exercise stress - neuroendocrines - immune status - acute stressors
- chronic stressors