Psychoneuroendocrinology
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Psychoneuroendocrinology · May 2005
The HPA axis response to stress in women: effects of aging and fitness.
This study tested the hypotheses that aging is associated with greater hypothalamic-pituitary-adrenal (HPA) axis reactivity to psychological stress, and whether aerobic fitness is associated with a lower HPA axis response to psychological stress. Three groups, consisting of young-unfit women (27.9+/-2.5 yr, n=10), older-unfit women (66.3+/-1.4 yr, n=14), and older-fit women (66.6+/-2.0 yr, n=12), underwent the Matt Stress Reactivity Protocol (MSRP). The MSRP is a stress test battery that combines mental challenges, a physical challenge, and a psychosocial stressor. ⋯ There were no significant differences between the older-unfit and older-fit in terms of heart rate or blood pressure responses. Our result shows that among unfit women, aging is associated with greater HPA axis reactivity to psychological stress, and that higher aerobic fitness among older women can attenuate these age-related changes as indicated by a blunted cortisol response to psychological stress. These findings suggest that exercise training may be an effective way of modifying some of the neuroendocrine changes associated with aging.