Aerobic physical activity and salivary cortisol levels among women with a history of breast cancer.

Background: Physical activity (PA) helps reduce cancer-related symptoms and improves overall functioning for women with and without a history of breast cancer (BC). Few researchers have examined the associations between PA and physiological stress measures. The aim of this study was to determine whether aerobic PA was associated with diurnal and reactive cortisol patterns, and whether these associations differed for women with and without a history of BC.

Methods: Participants were 25 women with a history of BC and 23 women without a history of BC who self-reported aerobic PA frequency. To assess diurnal cortisol patterns, participants provided five saliva samples collected on two consecutive days at the following times: upon awakening, 30 min after waking, 12 PM, 4 PM, and 9 PM. To measure reactive cortisol patterns, participants provided seven saliva samples collected before, during, and after doing the Trier Social Stress Test.

Results: Cortisol patterns differed statistically based on women's cancer history, whereby women without a history of BC had significantly higher overall cortisol reactivity to an acute stressor, and a marginally significant (p = .05) cancer experience by aerobic PA interaction was observed when analyzing diurnal cortisol data.

Conclusions: Findings suggest that PA may not have the same effect on women with and without a history of BC.