Physical activity moderates effects of stressor-induced rumination on cortisol reactivity.
Level 4 - case-series / case-control
Cross-sectional laboratory challenge study evaluating observational lifestyle differences
PubMed 21873586 · doi:10.1097/PSY.0b013e318229e1e0
What was done
Forty-six postmenopausal women completed the Trier Social Stress Test with repeated salivary cortisol sampling. Twenty-five minutes after the stressor ended, participants reported their level of stress-induced rumination. The researchers evaluated whether maintaining a physically active lifestyle moderated the relationship between rumination and log-transformed cortisol reactivity and recovery trajectories.
What was found
Physical activity moderated the initial rate (B = -0.10, standard error = 0.04, p < .05) and curvature (B = -0.03, standard error = 0.01, p = .06) of the relationship between rumination and log-transformed cortisol trajectories. Sedentary participants with higher rumination showed a more rapid initial cortisol rise (0.26 vs. 0.21, p < .001), a later peak (56 vs. 39 minutes), and delayed recovery (curvature: -0.07 vs. -0.08, p < .001) compared with sedentary participants with lower rumination. In active participants, cortisol trajectories remained equivalent regardless of rumination level.
Why it matters
This study provides physiological evidence that regular physical activity may buffer against prolonged hypothalamic-pituitary-adrenal axis activation provoked by acute psychological rumination.
Limits
The sample was small (n = 46) and limited entirely to postmenopausal women, restricting generalizability. Physical activity was an observational lifestyle variable rather than a randomized intervention, and rumination was assessed via self-report.
Cited by
- contradicts Studies by Eli Puterman show that exercise reduces ruminative thought processes.