Relationships between sports-specific characteristics of athlete's heart and maximal oxygen uptake.

Background: Improvement to maximal oxygen uptake is mainly due to myocardial adaptations brought about by physical training. As a consequence, the athlete's heart echocardiographic modifications associated with these adaptations are already well-known. We studied the relationships between maximal oxygen uptake (ml/min) and resting echocardiographic patterns in three athlete groups.

Methods: Tumbling (n=16), canoeing (n=12), cycling (n=12) and untrained (n=19) participants performed clinical examination and an echocardiogram. Trained groups performed a maximal graded exercise test on a cycle ergometer with gas exchange analysis.

Results: Sport-specific cardiac hypertrophy was observed. No significant echocardiographic difference was noted between untrained and tumbling participants. Canoeists showed higher end-diastolic thickness of the interventricular septum (P<0.001) and left ventricle mass (P<0.05) than untrained and higher posterior wall thickness (P<0.001) and than untrained and tumbling participants. In comparison between untrained, tumbling and cycling participants, left ventricular end-diastolic diameter (P<0.001) and left ventricular mass (P<0.001) was higher in cyclists. In trained subjects studied as a global group, the main linear correlation with maximal oxygen uptake concerned left ventricular end-diastolic diameter (r=0.92; P<0.001), left ventricular mass (r=0.60; P<0.001) and to a lesser extent aortic (r=0.39; P<0.01) and left atrium (r=0.36; P<0.05) diameters and E (r=0.38; P<0.05) and A (r=-0.33; P<0.05) Doppler peak velocities. Each trained group showed specific correlations between echocardiographic parameters and absolute maximal oxygen uptake. No further correlation was noted with left ventricular end-diastolic diameter or left ventricle mass when each group was studied individually.

Conclusions: In athletes, maximal oxygen uptake is partly linked to some resting echocardiographic parameters. Specific relationships between maximal oxygen uptake and some echocardiographic parameters in relation to the sport practised are also observed.