Abstract

Six world level, male (26.7+/-4.5years) windsurfers (WS) were tested with a laboratory windsurf simulator by which they performed several sequences of typical efforts in this sport. They were compared with six not trained (NT) subjects who performed the same exercise. During tests, subjects were connected, by means of a face mask, to an automatic, respiratory gas analyser. This apparatus displayed the values of: pulmonary ventilation, oxygen consumption, carbon dioxide production and respiratory quotient at 30-second intervals. Moreover, an impedance cardiograph, connected to the subject's chest by means of ten disposable electrodes, in the same time gave, non invasively, the value of: cardiac output, stroke volume, heart rate, ventricular contractility, end diastolic ventricular volume, cardiac work efficiency and total peripheral vascular resistance indices. During the exercise at the simulator, with respect to the NT group, the WS group showed: greater power output (+78%) and higher exercise duration (+108%), greater fall in total peripheral resistance (WS: -41%, NT: -30%) and respiratory quotient (WS: -13%, NT: -10%), lower increase in heart rate (WS: +20%, NT: +53%), higher increase in pulmonary ventilation (WS +151%, NT: +142%), stroke volume (WS: +42%, NT: +3%), cardiac output (WS: +64%, NT: 51%), ventricular contractility (WS: +44%, NT: -7%, end diastolic ventricular volume (WS: +4%, NT: +3%) and cardiac work efficiency (WS: +40%, NT: -4%). It was concluded that high level windsurfers require specific physiological adaptations in such a way as to set acute adjustments in these variables, adequate to high level performance. Verf.-Referat