Micro-bursts matter: vigorous intermittent lifestyle physical activity and risk of common brain disorders in a prospective cohort study.

BACKGROUND: Physical activity, particularly moderate-to-vigorous physical activity, is important for brain health; however, many adults do not meet recommended activity levels. Vigorous intermittent lifestyle physical activity (VILPA) may provide a feasible alternative. This study examined the associations of accelerometer-derived vigorous intermittent lifestyle physical activity with the risk of five common brain disorders. METHODS: This prospective cohort study used accelerometer data from the UK Biobank to quantify daily VILPA according to both duration and standardized frequency, using bouts lasting up to 1 min and up to 2 min. Incident anxiety, depression, dementia, Parkinson's disease, and stroke were ascertained through linked health records. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Restricted cubic spline models were applied to examine dose-response associations. Analyses were further stratified by exercise habit status. RESULTS: During a median follow-up of approximately 8 years, 2,150 anxiety (2.47%), 1,511 depression (1.81%), 676 dementia (0.74%), 343 Parkinson's disease (0.37%), and 1,385 stroke cases (1.55%) were identified. Higher VILPA frequency and duration were associated with lower risks of several brain disorders. Compared with the lowest quartile, modest VILPA levels were associated with reduced risks of anxiety (HR = 0.80, 95% CI: 0.71-0.90), depression (HR = 0.86, 95% CI: 0.75-0.99), dementia (HR = 0.72, 95% CI: 0.59-0.88), and Parkinson's disease (HR = 0.58, 95% CI: 0.43-0.78). Associations with stroke were weaker and less consistent. Dose-response analyses showed inverse nonlinear associations for anxiety, depression, dementia, and Parkinson's disease, characterized by a steep initial decline followed by a gradual plateau. Similar patterns were observed among both exercisers and non-exercisers. CONCLUSIONS: VILPA was associated with lower risks of several common brain disorders. Incorporating brief bursts of vigorous movement into daily life may represent a feasible strategy for promoting brain health.