Curvilinear dose-response association of physical activity with clinically diagnosed stress: Prospective cohort with 74,000 individuals

This study examined the prospective dose-response association of accelerometer-derived physical activity with clinically diagnosed stress. We included adults aged 40 to 69 years from the UK Biobank cohort, free of severe disease at baseline, who participated in accelerometer measurements. Moderate- to vigorous physical activity (MVPA) at baseline was derived through one-week wrist-worn accelerometry. Clinically diagnosed severe stress at follow-up was defined by hospitalization with ICD-10 codes Z73.3 (stress, not elsewhere classified) and Z56.6 (work-related stress). Restricted cubic splines determined the prospective dose-response association between MVPA and stress, adjusting for relevant confounders. The study followed 74,715 individuals (mean age 55.2 years SD 7.8; 58% women); for a median of 7.9 years, during which 533 individuals (0.7%) developed stress. Higher levels of MVPA were curvilinearly associated with reduced stress risk, with the steepest minute-per-minute risk reduction from 15 (HR 0.98 95%CI, 0.96–0.99) to 220 (HR 0.74 95%CI, 0.59–0.92) minutes per week. The greatest risk reduction was observed at 1230 minutes per week (HR 0.59 95%CI, 0.35–0.99). A curvilinear dose-response association exists between MVPA and reduced risk of clinically diagnosed stress, with the greatest minute-per-minute incremental benefits observed from 15 to 220 minutes per week. • A curvilinear association exists between MVPA and reduced risk of diagnosed stress • The greatest minute-per-minute incremental benefits are observed in the range from 15 to 220 min/week • Public health guidelines should recommend about 30 min of MVPA/day to prevent stress