[Steady state ergometry: fact or fiction]

The steady state is a physiological condition whereby the metabolic requirements are met and the criteria parameters are stable. Four groups of male subjects were evaluated on their VO2 for a one hour duration ergocycle effort at 75%, 50%, 25% and 10% of their maximum individual VO2. Three cardio-respiratory parameters (heart frequency, oxygen consumption, pulmonary ventilation) and one biochemical parameter (lactic acid) were measured The evolution of the control parameters during the task were completed according to the requirements of the literature. For the long-duration efforts (one hour) we notice the absence of a steady-state for the cardio-respiratory parameter. We cannot however rule-out the existence of a steady state for the biochemical parameter for the lighter efforts of 10% and 25% of the VO2 maximum.