TOPLINE:

Young competitive cyclists showed greater left ventricular enlargement and exercise‑related ECG changes than master cyclists; however, right ventricular size was similar, and weekly training hours were the main predictor of left ventricular size.

METHODOLOGY:

• Researchers in the UK and Spain conducted a cross-sectional study involving 112 competitive cyclists to assess how aging affected cardiac adaptation to endurance training.
• They included 53 young cyclists (mean age, 25 years; 81% men) and 59 master cyclists (mean age, 52 years; 76% men), with master cyclists having more than 10 years of consistent endurance training.
• All participants completed a health questionnaire and underwent 12-lead ECG and transthoracic echocardiography.
• Researchers analysed heart rate, electrical findings, chamber sizes, wall thickness, and right ventricular function using the standard criteria.
• Young cyclists trained an average of 6.6 days per week and 21.9 hours weekly, and master cyclists trained an average of 4.8 days per week and 10.3 hours weekly.

TAKEAWAY:

• Young cyclists more often had bradycardia (< 60 heart beats/min) than master cyclists (83% vs 63%; P = .016) and more often met the ECG voltage criteria for left (53% vs 18%; P < .001) and right (15% vs 2%; P = .01) ventricular hypertrophy.
• Young cyclists had a larger left ventricular end-diastolic diameter than master cyclists (55 vs 51 mm; P < .001), with more of them showing values greater than 58 mm (26% vs 3%; P < .001) and eccentric left ventricular hypertrophy (26% vs 12%; P = .049).
• Only weekly training hours were independently associated with a greater left ventricular end-diastolic diameter (B, 0.215; P = .015).
• The right ventricular outflow tract diameter was 33 mm in both groups, with no significant difference (P = .383). Abnormal ECG findings were uncommon overall.

IN PRACTICE:

"[The study] results suggest that, despite lifelong training exposure, masters cyclists demonstrate attenuated LV [left ventricular] remodeling compared with younger cyclists, who show greater LV dilation and a higher prevalence of eccentric hypertrophy," the authors wrote.

"Significant structural changes in older athletes should therefore prompt careful evaluation for underlying pathology," they added.

SOURCE:

This study was led by Irene Juanes, University Hospital of Araba, Vitoria-Gasteiz, Spain. It was published online on December 26, 2025, in the European Journal of Preventive Cardiology.

LIMITATIONS:

The cross‑sectional design of this study precluded any cause‑effect relationships. Participants were mostly Caucasian men, which limited generalisability. Researchers excluded individuals with cardiovascular risk factors and did not have controls for training intensity and regimens.

DISCLOSURES:

One author received a mobility grant from the Sociedad Española de Cardiología for this collaborative research. The authors declared having no conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.