Arrhythmias & electrophysiology
Accelerometer-measured physical activity timing and risk of incident atrial fibrillation: a UK Biobank cohort study
Main finding · Incident AFResult — go to the resultHazard ratio 0.79 95% CI 0.70–0.89Authors' conclusion
Regular MVPA at any time was associated with lower AF risk, with exploratory evidence suggesting greater benefit in the morning, particularly among younger adults and those with comorbidities.
Study context
- Population
- UK Biobank participants free of atrial fibrillation (AF) at baseline3,815 incident AF
- Participants
- 88,024 participants
- Exposure
- Moderate-to-vigorous physical activity (MVPA) timing patterns vs inactivity
- Outcome
- Incident AF
- Follow-up
- Median 7.87 years
Methodological detailsUK Biobank, accelerometer-measured, multivariable-adjusted Cox models
- UK Biobank
- Accelerometer-measured
- Multivariable-adjusted Cox models
Main finding
Incident AF
Hazard ratio
0.79
95% CI 0.70–0.89
P < 0.001
Morning vs Inactive
HR 0.79 (95% CI 0.70–0.89); P < 0.001
As reported in the abstract
Observational data: associations, not effects.
Further findings
| Outcome | HR | P value |
|---|---|---|
| Incident AF, DM (subgroup) — Morning vs Inactive | 0.66 | P = 0.001 |
| Incident AF, DM (subgroup) — Afternoon vs Inactive | 0.77 | P = 0.025 |
| Incident AF, no DM (subgroup) · greatest benefit | 0.76 | P = 0.029 |
| Incident AF, hypertension (subgroup) | 0.74 | P < 0.001 |
- Incident AF, hypertension (subgroup): greatest benefit; activity at any time associated with reduced risk
Incident AF, age <65 years (subgroup)
- Adults < 65 years benefited most from morning exercise
Incident AF, no hypertension (subgroup)
- Timing of activity made little difference
Original publication
Accelerometer-measured physical activity timing and risk of incident atrial fibrillation: a UK Biobank cohort study. Eur J Prev Cardiol. Published 23 September 2025. doi:10.
Summarised from the published abstract; every number is checked against it