BACKGROUND: Chronic exercise training is associated with "athletes` heart", characterised by enhanced left ventricular (LV) mass and dimensions. It is not known whether these structural adaptations alter cardiac diastolic function or if there are simultaneous changes in structure and function of the vasculature. METHODS: High resolution vascular and cardiac ultrasonography was performed in 35 elite level athletes from WA Institute of Sport and 12 matched untrained controls. Measures were repeated following 3 month intensive training in the athletes. RESULTS AND DISCUSSION: Compared to controls, the athletes possessed higher SV, due to increased diastolic LV dimensions (P<0.01). Athletes also displayed increased LV thickness (P<0.02) and mass (291±9.4 v 222±18.1g;P<0.01), whilst ejection fraction (EF) did not differ between the groups. LV structural changes in the athletes were associated with a reduction in diastolic function (colour M-mode Propagation, deceleration time and atrial reversal; P<0.02), relative to controls, at baseline. The athletes displayed larger conduit and resistance vessel structure than controls (P<0.01), both at rest and during exercise. Following intensive training in the athletes, there was a further increase in cardiac structure, associated with enhanced systolic (P<0.01) and diastolic (P<0.05) function, conduit vessel enlargement (4.49±0.1 v 4.91±0.8mm;P<0.01) and changes in blood flow distribution during exercise (P<0.05). CONCLUSION: These data indicate for the first time in humans that exercise training is associated with changes in cardiac structure with corresponding improvements in cardiac function. In addition, these cardiac changes occur in concert with changes in peripheral vascular structure, and function during exercise.
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