Aerobic Fitness Level and Reactivity to Psychosocial Stress: Physiological, Biochemical, and Subjective Measures

Abstract

Aerobic fitness is associated with numerous physiological adaptations which permit physical stress to be coped with more efficiently. The present experiment examined whether aerobic fitness influences emotional response. Heart rate, biochemical measures (catecholamines, cortisol, prolactin, lactic acid), and self-reported arousal and anxiety were monitored in 15 highly trained and 15 untrained subjects at various points before, during and following exposure to a series of psychosocial stressors. Heart rate and subjective arousal level increased markedly during the stressors in both groups. Trained subjects showed higher levels of norepinephrine and prolactin early in the stress period, more rapid heart rate recovery following the stressors, and lower levels of anxiety at the conclusion of the session. This more rapid heart rate and subjective recovery from psychosocial stress, suggests that aerobically trained individuals may be capable of faster recovery in both physiological and subjective dimensions of emotionality. The differences in reactivity profiles between the aerobically trained and untrained were discussed in light of models that have dealt with the adaptiveness of emotional response.

The level of physical activity affects adrenal and cardiovascular reactivity to psychosocial stress

“…This finding confirms previous findings of lower cortisol responses to psychosocial stress of elite sportsmen compared with untrained men in another sample (Rimmele et al, 2007). The similar cortisol responses in amateur sportsmen and untrained men observed here are also consistent with previous studies that likewise did not reveal differences in cortisol reactivity to psychological stressors among amateur sportsmen of differing levels of fitness or between amateur sportsmen and sedentary subjects (Sinyor et al, 1983;Moyna et al, 1999). Chronic physical exercise is associated with reduced HPA axis activation if the experimental stressor is of the same absolute physical intensity (Luger et al, 1987), and high HPA axis responders to exercise stress are also highly responsive to psychological stress (Singh et al, 1999).…”

Catecholamine training effects from exercise programs: A bridge to exercise-temperament relationships

“…(This finding supports the correlational finding of Sinyor et al, 1983), noted earlier.) At postsemester, while Nonexercisers remained constant, adrenaline levels for the Aerobics subjects almost doubled (t = 2.37, P < .05, twotailed), approximating both the pre-and postsemester levels of the Marathoners.…”

“…The only study (other than ours) investigating similar relationships with humans used a correlational approach (Sinyor, Schwartz, Peronnet, Brisson, & Seraganian, 1983). Newspaper ads recruited 15 exercisers and 15 nonexercisers who were then compared for physiological responses to challenging tasks (e.g., mental math, Stroop task).…”

Preliminary evidence that exercise dependence is associated with blunted cardiac and cortisol reactions to acute psychological stress

“…The group difference in HR reactivity survived such adjustment, F (1, 17) = 6.76, p= .02, η2 = .284. Since there is no similarly compelling evidence that cardio-respiratory fitness affects cortisol stress reactivity (Sinyor et al, 1983) we did not adjust for fitness in our cortisol analysis. However, women in the luteal phase of the menstrual cycle have been shown to exhibit greater cortisol responses to acute stress than women in the follicular phase or women taking oral contraceptives (Kirschbaum et al, 1999), thus we revisited the cortisol analysis adjusting for menstrual cycle phase and/or oral contraception.…”