Differential dose–response associations of leisure-time and non-leisure-time physical activity with perceived stress in middle-aged and older adults

We examined the dose–response associations of leisure-time and non-leisure-time moderate-to-vigorous physical activity (LT-MVPA and NLT-MVPA, respectively) with high perceived stress among middle-aged and older adults. We cross-sectionally analyzed baseline data from 15,688 adults (6377 men and 9311 women) aged 40–74 years enrolled in the Yamagata Cohort Study. Perceived stress, LT-MVPA, and NLT-MVPA were assessed using questionnaires. Multivariate-adjusted prevalence ratios (PRs) and 95% confidence intervals (CIs) for high perceived stress were estimated using modified Poisson regression. Dose–response relationships were evaluated using restricted cubic splines. In both sexes, LT-MVPA showed an L-shaped association with high perceived stress, with PRs reaching a nadir at approximately 5.0 metabolic equivalent (MET)-hours/day (men: 0.68 [95% CI 0.57–0.82]; women: 0.81 [0.74–0.89]). For NLT-MVPA, men showed a J-shaped association, with the lowest PR at around 15 MET-hours/day (0.78 [0.63–0.96]) and no significant benefit at ≥ 22 MET-hours/day. In contrast, women showed a saturating association, with the highest PR at 20 MET-hours/day (1.27 [1.14–1.42]), remaining elevated at higher levels. LT-MVPA showed a consistent L-shaped association with high perceived stress in both sexes, whereas NLT-MVPA showed sex-specific, non-linear associations. These findings suggest that stress management strategies should account for both MVPA domain and sex.