METHODS

Subjects. Twenty-eight healthy players recruited from an Italian elite male soccer team aged between 17 and 29 yr (mean 20.2 4.4) were studied during pretraining period and after seven months of training (36 h after the last training section). As controls, we studied 155 healthy male subjects (mean age 23 2.3), untrained students of the Medical School of the University of Florence. In 28 control subjects, echocardiographic study was also performed. All the subjects were Caucasian, nonconsanguineous, and gave informed consent to genotyping. Echocardiographic methods. Mono-two-dimensional echocardiographic examinations were performed using an Esaote device (AU3–3.5 2.5 MHz probes Esaote Biomedica Florence, Italy).

Parasternal long axis, short axis, apical four chambers with aorta and when necessary subcostal views were used. The interventricular septum and posterior wall thickness, systolic and diastolic LV dimensions and ejection fraction were measured, by means of leading edge technique, with monodimensional echocardiography under two dimensional guide (15).