ABSTRACTAimsTo explore the causal relationship between physical activity (PA) and the progression of Parkinson's disease (PD), we conducted a two‐sample Mendelian randomization (MR) analysis.MethodsGenetic variants were obtained from publicly available genome‐wide association study (GWAS) summary statistics for PA (N = 377,000), age at onset (N = 28,568), and PD progression (N = 4093). Causal estimates were calculated using the inverse variance weighted (IVW) method, with MR‐Egger and weighted median analyses performed to assess the robustness of the results.ResultsGenetically predicted accelerometer‐based overall acceleration average (OAA) was associated with a reduced risk of constipation in PD progression (OR: 0.60, 95% CI: 0.42–0.86, p = 5.50 × 10−3). Moderate‐to‐vigorous physical activity (MVPA) demonstrated a similar but stronger effect on constipation risk (OR: 0.03, 95% CI: 9.38 × 10−4–0.90, p = 0.043). Additionally, OAA showed a protective effect on motor experiences of daily living (OR: 0.84, 95% CI: 0.71–1.00, p = 0.046). No causal effects were identified for vigorous physical activity (VPA) or the fraction of accelerations exceeding 425 milligravities (FAA) on PD progression.ConclusionOur findings suggest a negative causal relationship between PA and PD progression, highlighting the potential role of physical activity in guiding therapeutic strategies for PD management.