Association of physical activity volume with the risks of nervous system diseases: a retrospective cohort study

Background Physical activity volume (PAV) has been linked to a wide range of health outcomes; however, its association with incident nervous system diseases remains incompletely understood. This study explored their relationship using data from UK Biobank. Methods A retrospective cohort study was conducted involving 278,306 participants from the UK Biobank. PAV was quantified as metabolic equivalent of task (MET) minutes per week, derived from self-reported physical activity levels, and categorized into three groups. Incident cases of nervous system diseases were identified through ICD-10 codes obtained from hospital inpatient records, death registries, and self-reports. Cox proportional hazards models were employed to estimate hazard ratios (HRs) and 95% confidence intervals (CIs), adjusting for a series of covariates. Restricted cubic splines were applied to assess potential non-linear associations. Results Women and individuals aged 60 years or older exhibited higher incidence rates of nervous system diseases. After multivariable adjustment, higher PAV was significantly associated with a lower risk of overall nervous system diseases (HR < 1). A non-linear dose–response relationship was observed, with the lowest risk occurring at a PAV level of 1,356 MET-min/week. Subgroup analyses indicated that elevated PAV conferred protective effects against several specific conditions. Conversely, higher PAV was associated with an increased risk of meningitis. Conclusion Increased levels of physical activity are associated with a reduced risk of numerous nervous system diseases, with optimal protection observed at approximately 1,356 MET-min/week. These findings support the promotion of moderate-to-vigorous physical activity as a preventive strategy for neurological disorders, particularly among high-risk populations.