Abstract
Social self-threat during physical stress, such as exposure to the cold pressor test and isometric handgrip test, has been shown to induce activation of the HPA axis, in addition to autonomic responses. However, previous research has suggested that dysfunctional post-event processing may play a major role in neuroendocrine reactivity at initial as well as subsequent social stress exposure. In the present study, we investigated how the interplay of context (i.e. performance feedback) with state (i.e., self-esteem) as well as trait-like factors (i.e., ruminative tendencies) affects stress responses to repeated, short bouts of physical activity. On two sessions, 1 week apart, 53 participants (27 women) performed an isometric handgrip task for 3min, during which they were exposed to social-evaluative threat. In addition, participants received fake feedback on their performance immediately after the task, labeling it as either 'above' (positive) or 'below average' (negative). In addition to neuroendocrine (cortisol), cardiovascular (heart rate, blood pressure) and subjective stress reactivity, performance-related and social dimensions of state self-esteem were assessed before and after stress induction. Substantial increases in cardiovascular parameters were found on both days, regardless of feedback condition. However, positive feedback led to significantly diminished neuroendocrine responses on day 1, whereas baseline cortisol on session 2 was significantly higher in the negative feedback group. Conversely, social self-esteem decreased after stress induction on both days only for participants who had received negative feedback. Changes in self-esteem reported on day 1 were associated with increased baseline cortisol at the second session, while interindividual differences in self-reported (trait) rumination were associated with cortisol reactivity at session 1. Taken together, the results suggest that effects of social evaluation during short periods of physical stress rely on post-event processing and might be counteracted by positive appraisal directly after stress exposure. Post-hoc framing (in terms of success vs. failure) may predict subsequent stress-related hormonal effects better than task demands per se, which should be considered as a potential moderator in future acute stress research, but might also be relevant to many practical applications in fields ranging from sports/performance to health psychology.