Cycling Linked to Higher Arrhythmia Risk in Middle-Aged Men

 Middle-aged men who logged more hours of lifetime endurance exercise were more likely to report atrial fibrillation (AF) or atrial flutter, with cycling independently associated with higher odds of self-reporting either condition.

METHODOLOGY:

• Researchers conducted a cross-sectional analysis of data from screening questionnaires from the Master@Heart study to assess the association between lifetime endurance exercise and the risk for AF or atrial flutter.
• They analysed responses from 3939 men (median age range, 55-59 years) recruited in Belgium between October 2018 and May 2022 through a public campaign.
• The survey collected data on demographics, cardiovascular risk factors, medications, known heart conditions, and detailed weekly hours and years of participation in 22 sports.
• Researchers classified cycling, running, rowing, swimming, duathlon, and triathlon as endurance sports and calculated lifetime exercise hours by multiplying weekly hours by years of participation. Based on lifetime exercise hours, participants were grouped into quartiles (Q1 ≤ 1778 hours; Q2 > 1778 to ≤ 5977 hours; Q3 > 5977 to ≤ 12,231 hours; Q4 > 12,231 hours).
• The primary outcome was self‑reported history of AF and/or atrial flutter.

TAKEAWAY:

• Overall, 7.5% of participants reported a history of AF or atrial flutter.
• The prevalence of AF or atrial flutter increased significantly across quartiles of lifetime exercise, from 4.8% in Q1 to 9.6% in Q4.
• The adjusted odds of reporting AF or atrial flutter were 1.86-fold higher among participants in Q2, 1.90-fold higher among those in Q3, and 2.16-fold higher among those in Q4 (P < .01 for all) than among those in Q1.
• Cycling was independently associated with 1.51-fold higher odds of reporting AF or atrial flutter (P = .010) after adjusting for traditional risk factors and cumulative exercise volume.

IN PRACTICE:

"[The study] findings contribute to growing evidence suggesting that high-volume endurance training may increase the risk of AF, even in individuals with a favourable cardiovascular risk profile," the researchers of the study wrote.

SOURCE:

The study was led by Jarne De Paepe, MD, of KU Leuven in Leuven, Belgium. It was published online on May 22, 2026, in European Heart Journal Open.

LIMITATIONS:

The study was cross-sectional and relied on self-reported data. The questionnaire did not capture data on exercise intensity or low-intensity activities. History of AF or atrial flutter was reported via a single survey question without confirmation from ECG or medical records.

DISCLOSURES:

The study received research grants from the Research Foundation — Flanders, Abbott Belgium, and Boston Scientific Belgium. One author reported receiving support from the Research Foundation — Flanders, and another reported being a senior clinical investigator at the foundation.

https://www.medscape.com/viewarticle/cycling-linked-higher-arrhythmia-risk-middle-aged-men-2026a1000hya