Cardiac remodeling in amateur triathletes after 24 weeks of exercise training for a half-Ironman event: a brief report

BACKGROUND: Triathletes’ physiological adaptations to exercise training can have a different impact on cardiac remodeling based on the extreme exercise preparation. Moreover, cardiac remodeling might be different depending on whether triathletes have trained for many years or if they just decided to be more active. Nevertheless, data are limited in amateur endurance athletes and studies about them are key for their safety. Therefore, we investigated the effects of exercise training for a half-ironman on cardiac remodeling. METHODS: A total of 24 amateur athletes underwent a 24-week exercise program and were followed by three-dimensional echocardiography to assess its global impact on cardiac remodeling. Subanalyses were performed based on participants past-training experience (low versus high). RESULTS: We found significant group effects on the right and left ventricle, significant time effect on the right ventricle. No significant interaction effects were observed. We observed significant correlations between the right ventricle, clinical and performance characteristics where the peak power output explained 38% of the variance, while the body surface area, weight and power at the second ventilatory threshold explained 34%, 31% and 30%, respectively. CONCLUSIONS: Changes in cardiac remodeling in response to an exercise program for a half-ironman are not homogeneous across the ventricles and are influenced by participants’ past-training experience. This study strengthens our knowledge of extreme exercise training for a half-ironman to further develop better training programs and medical follow-up in amateur triathletes.