Insufficient or excessive exercise activities are associated with suboptimal treatment outcomes in patients with psoriasis: a longitudinal study in shanghai, China

Background Physical activity’s impact on psoriasis treatment outcomes is unclear. This study examines associations between exercise levels and treatment response in psoriasis patients.Methods In a longitudinal study of 1,116 psoriasis patients (2022–2024), physical activity was assessed via MET-min/week and categorized as inactive (<150), low (150–<500), moderate (500–<1000), or high (≥1000). Severity (PASI/BSA) and PASI50 response were evaluated at baseline, week 4, and week 8. Analyses used logistic regression and restricted cubic splines.Results Among participants (74.4% male, mean age 46.1), week 8 PASI50 rates were 61.2% (inactive), 75.1% (low), 69.9% (moderate), and 66.7% (high). Low activity was linked to higher odds of PASI50 (adjusted OR = 1.58; 95% CI: 1.01–2.79) versus inactivity. A J-shaped nonlinear association emerged (p = 0.023): response probability rose rapidly at low exercise levels, peaked at 150–500 MET-min/week, the benefit plateaued or attenuated at higher intensities (≥1000 MET-min/week).Conclusion Moderate physical activity (150–500 MET-min/week) is associated with better psoriasis treatment outcomes, with diminishing benefits at very low or high levels. Findings support personalized, intensity-based exercise recommendations.