Comparative Electrocardiographic Analysis Between Physical Exercise Practitioners and Athletes: A Cross-Sectional Study

The trained heart adapts through geometric changes influenced by concentric and eccentric hypertrophy, depending on the predominance of the isometric or dynamic components of the exercise performed. Additionally, alterations in heart rhythm may occur due to increased vagal system activity. Cardiological evaluation with an electrocardiogram (ECG) aims to identify cardiac conditions that could temporarily or permanently disqualify an athlete from competition. This study sought to compare electrocardiographic findings in regular exercisers with those observed in athletes and to correlate these findings with training duration and load. A cross-sectional study was conducted with 154 participants divided into two groups: exercisers (EG) and athletes (AG). Data were collected on exercise type, weekly training time and practice duration. Each participant underwent a resting ECG, analyzed by two independent physicians, with a third review in case of disagreement. The Seattle criteria were applied to categorize ECG changes as physiological, borderline or abnormal. The findings revealed that 75% of athletes exhibited ECG changes, with left and/or right ventricular hypertrophy and incomplete right bundle branch block (IRBBB) being the most prevalent. Age (PR = 0.92; <i>p</i> = 0.004) and exercise duration (PR = 1.00; <i>p</i> = 0.004) significantly influenced the observed electrocardiographic changes. The majority of both regular exercisers and athletes displayed ECG alterations, with the prevalence increasing with age and training duration.