Abstract
Many studies have examined physiological responses to acute stress in healthy and clinical populations. Some have documented exaggerated physiological stress reactivity in response to acute stress, while others have reported blunted physiological stress reactivity. Although the literature is conflicted, the relationship between abnormal physiological stress reactivity and negative outcomes is well-established. However, past research has neglected a critical aspect of physiological stress response - respiration - and it is unclear whether differences in respiration rate responses to acute stress are related to health outcomes. This secondary cross-sectional analysis explored differences in outcomes between three subgroups: blunted, moderate, and exaggerated respiration rate reactivity to an acute stress task. In a sample of at least mildly-stressed older adults (n = 55), we found that perceived stress (b = -7.63; p = .004) and depression (b = -9.13; p = .007) were significantly lower in the moderate reactivity group compared to the high reactivity group, and that self-reported mindfulness (b = 10.96; p = .008) was significantly lower in the moderate reactivity group as compared to the low reactivity group. Across outcomes, participants in the moderate range of physiological reactivity showed less negative and more positive psychological attributes and better health outcomes, while the blunted subgroup demonstrated more negative and less positive psychological attributes and worse health outcomes overall, when compared to the exaggerated and moderate groups. This study extends the literature by adding respiration to markers of acute physiological stress reactivity and demonstrating the effects of blunted respiration reactivity on negative psychological attributes and health outcomes.