Relation Between Aerobic Fitness Level and Stress Induced Alterations in Neuroendocrine and Immune Function

Alterations in neuroendocrine and immune function were examined in sedentary (n = 15) (VO₂peak; 31.4±0.7 ml·kg^-1·min^-1; 24.4±1.2 yr), moderately active (n=15) (VO₂peak; 45.4±1.1 ml·kg^-1·min^-1; 24.2±1.1 yr) and aerobically trained (n = 15) (VO₂peak; 58.8±0.9 ml·kg^-1·min^-1; 24.3±1.0 yr) men following exposure to an acute mild psychological stressor. Subjects had 2 min to prepare, and 3 min to deliver a speech in front of 3 observers. Blood samples were drawn from an indwelling catheter before, during and 30 min following the speech task (ST). Self-reported measures of anxiety were obtained prior to and immediately following the stressor. The ST resulted in significant alterations in the number and function of immune cells, and in self-reported anxiety scores. Plasma levels of norepinephrine increased during the speech task. The neuroendocrine and immune response to the chosen stressor were independent of subject aerobic fitness level.

Key words

Stress - immune function - aerobic capacity - norepinephrine - Cortisol