Overview

• Lower aerobic fitness was tied to a notably higher burden of frequent and complex atrial arrhythmias, while advancing age also correlated with ventricular irregularities.
• Risk climbed roughly 9% per year for atrial and 4% per year for ventricular arrhythmias, with a marked rise beginning around ages 50 to 54.
• The analysis of 1,151 asymptomatic adults aged 40 to 65 (88% men) used exercise stress testing with continuous ECG monitoring to quantify ectopy burden.
• Participants with low fitness had an estimated 52% higher risk of irregular heartbeat disorders, according to results presented at ESC Congress 2025 in Madrid.
• Researchers recommend considering arrhythmia screening from about age 50 and stress that the observational, male‑dominant sample means the results are preliminary and need peer‑reviewed confirmation.