Relationship between Cardiorespiratory Dynamics and Maximal Aerobic Capacity in Exercising Men

Abstract

Some respiratory reactions show a relation to the physical fitness of an individual indicating that respiratory mechanisms can play a role in functional adaptation to exercise in man. Stegemann (1981) has reported that trained and untrained persons have the same ventilation at rest but that this is achieved with different ratios of frequency and tidal volume when the respiratory center is stimulated at rest by CO₂. As was shown by Yearg et al. (1985) the exercise equivalent for oxygen (V̇E/V̇O₂) decreases and maximal achievable ventilation (V̇Emax) increases in the course of endurance training. It is also reported that at the onset of exercise oxygen uptake and ventilation increase more rapidly toward the steady state in trained than in untrained men (Hagberg et al., 1980). The latter finding has an important bearing on the estimation of the oxygen deficit developing in man at the beginning of heavy exercise. It is not clear, however, whether the faster response of ventilation is a specific result of the training applied, or whether it is a physiological reaction connected with the level of maximal aerobic capacity (V̇O₂max) regardless of training. The purpose of this study was, therefore, to test the dynamics of respiratory response to exercise in relation to the individual level of V̇O₂max in a group of untrained men.