[Recent data on respiratory control during muscular exercise in man].

During the last two decades, numerous investigations have been conducted to determine the degree of involvement and mechanism of action of various factors responsible for ventilatory adaptation to exercise in human. The neuromechanical ventilatory system plays a role, exercise ventilation representing a compromise between the necessity of maintaining an adequate level of chemical arterial stimulus and of avoiding mechanical overload and, consequently, respiratory fatigue. The role of arterial chemoreceptors is essential and that of muscular chemoreceptors likely. The limb mechanoreceptors also play a role essentially via small nerve fibers on the other hand. To date, there is no experimental evidence of ventilatory reflexes elicited by pulmonary chemoreceptors. Further, the action of cardiopulmonary baroreceptors was proved only in extraphysiological conditions in animals. It is also possible that a feed-forward mechanism originating in the central nervous system plays an important role. In conclusion, the time course of pulmonary ventilation during exercise could be explained by the action of humoral and neurogenic stimuli.