Abstract
Background/Objectives: Telomeres and the enzyme telomerase play essential roles in cellular aging and cardiovascular health. Physical activity is thought to influence telomere dynamics via upregulation of the hTERT gene, which encodes the catalytic subunit of telomerase. However, data on this relationship in middle-aged endurance athletes remain limited. This study aimed to investigate the association between long-term endurance training, cardiac structural adaptations, and hTERT gene expression in middle-aged elite athletes. Methods: A total of 38 middle-aged elite runners and 37 age-matched sedentary controls were enrolled. Echocardiographic assessments, VO(2)peak measurements, and hTERT gene expression analysis using RT-PCR were conducted. Left ventricular mass (LVM), wall thicknesses, and cardiac volumes were compared, and correlations with hTERT expression were analyzed. Results: Athletes demonstrated significantly higher VO(2)peak and echocardiographic parameters including LVEDD, LV mass, and wall thicknesses (p < 0.05). hTERT gene expression was 2.06-fold higher in athletes compared to controls. Significant positive correlations were observed between hTERT expression and VO(2)peak, LVM, LV wall thicknesses, and right ventricular parameters. Conclusions: These findings suggest that regular aerobic exercise may contribute to both improved cardiovascular performance and cellular longevity by enhancing telomerase-related mechanisms.