PULMONARY GAS-EXCHANGE IN ATHLETES WITH EXERCISE-INDUCED HYPOXEMIA

Hypoxaemia that is induced by physical exercise (EIH) in some athletes , who are however capable of enduring intense muscolar work, is a phen omenon that has been known for some time. However, assumptions such as alveolar hypoventilation, veno-arterial shunt, limitation of diffusio n, or mis-march of the V-A/Q ratio, have not to date been able to exha ustively explain this phenomenon. Ln this study five athletes displayi ng exercise-induced hypoxaemia were evaluated by increasing-load exerc ise tests, as proposed by other authors, and hy means of intermittent tests with supermaximal exercise steps (130% VO2 max) with breaks for incomplete recovery (3 min). The fundamental fact arising from our stu dy is that the intermittent tests did not bring about hypoxaemia in th e tests subjects. Analysis of the ventilator and metabolic parameters, of the alveolar pressure of the O-2, and of the partial pressures of the CO2 in the arterial blood, all measured during the two different t ypes of muscular exercise, lead to the belief that the different distr ibution of the pulmonary blood flow which has been documented in highl y trained athletes, plays a very important role in inducing EIH.