Intense endurance training has no negative effects on cardiovascular health according to a study conducted by sports physicians in Italy, Japan, and the US.
The findings published this month in the Journal of the American College of Cardiology indicate that “over prolonged periods of training and competition (up to 17 years), no cardiac events or new diagnoses of cardiomyopathies occurred in the the research group of 114 Olympic athletes.”
While the study abstract does not mention the impact of long periods of training and racing on amateur or age-group athletes, one would expect the results to be similar.