A psychobiological approach to the investigation of exercise-related affect

Although it is well documented that exercise participation is associated with affective benefits, the mechanisms underlying this relationship are not clearly understood. The purpose of the present study was to take a psychobiological approach to the investigation of exercise-related affect. Specifically, the relationships between physical activity level, self-efficacy, cortisol responses, and affective change associated with an acute bout of treadmill running were examined. Subjects for the study comprised 60 (50 male; 10 female) undergraduate students who participated in a 30 minute treadmill trial at 60% VO$\sb{2\rm max}$. The results indicated that physically active subjects demonstrated enhanced affective responses compared to less active subjects. Also, active subjects possessed higher levels of self-efficacy (p $<$.001) pre- and post-exercise compared to their less active counterparts. Furthermore, post-exercise cortisol levels were lower in the physically active subjects (p $<$.05).With respect to the relationships among the variables in the study, it was found that (a) activity level predicted affective responses during exercise and was related to enhanced affective change post-exercise, (b) activity level predicted cortisol levels during exercise and was inversely related to cortisol level post-exercise, (c) low cortisol levels were related to higher self-efficacy post-exercise, (d) enhanced affective responses during exercise were related to lower cortisol levels post-exercise, and finally (e) self-efficacy predicted affective responses during exercise and was related to enhanced affective responses post-exercise.Many of the findings were interpreted and discussed within Bandura's (1986) social cognitive framework which postulates mastery experiences to impact upon perceptions of personal capabilities, which in turn will be related to affective states. Moreover, a tenet of Dienstbier's (1989) model of physiological toughness was tested. The tenet states that regular aerobic exercise results in suppressed cortisol responses to exercise, which in turn will be related to enhanced emotional function. In conclusion, the findings of the study suggest that affective changes associated with acute exercise are most likely determined by the interaction of psychological and physiological processes.U of I OnlyETDs are only available to UIUC Users without author permissio