RESUMO
The changes of pulmonary rheography of 12 bikers were investigated after they had been physically trained under hypoxic condition in a hypobaric chamber simulating altitudes of 2000 m, 3000m, and 4000m respectively. All the bikers were permanent inhabitants at 1895 meters above sea level.The changes were most marked on the rheographies taken at the simulated altitude of 4000m. Comparing with the control values at the sea level, the authors found that tonic interval (Q-a interval) on the bikers' pulmonary rheographies was prolonged. The amplitude, the mean rate of filling and the rate of maximal ascending of the systolic wave were decreased.The results showed that hypoxic physical training could result in the contraction of pulmonary vessels. In turn it caused pulmonary arterial hypertension and reduced the amount of blood circulating through the lungs. Pulmonary arterial hypertension could further increase the afterload of the right ventricle.Eight days after the bikers returned to the sea level, all the indices also returned to their original levels except the tonic interval. It is apparent that these changes are most likely to be functional rather than organic.