The addition of inspiratory resistance increases the amplitude of the slow component of O 2 uptake kinetics

The contribution of respiratory muscle work to the development of the slow component is a point of controversy since it has been shown that the increased ventilation in hypoxia is not associated with a concomitant increase in V slow component. The first purpose of this study was thus to test the hypothesis of a direct relationship between respiratory muscle work and slow component by manipulating inspiratory resistance. Since the conditions for a slow component specific to respiratory muscle can be reached during intense exercise, the second purpose was to determine whether the respiratory muscles behave like limb muscles during heavy exercise. Ten trained subjects performed two 8-min constant-load heavy cycling exercises with and without a threshold valve in random order. was measured breath-by-breath using a fast gas exchange analyzer, and the O 2 O V