Possible Mechanisms of Oxygen Uptake Kinetics

Abstract

The VO₂ response to a step change in work rate resembles a first order exponential function. This suggests that a single site of the many which link ATP demand to VO₂ is limiting. The location of this site is controversial. Some authors suggest that O₂ delivery regulates the VO₂ response. Others have suggested that peripheral mechanisms within the active muscle regulate O₂ consumption. The evidence supporting each hypothesis is reviewed. It is concluded that O₂ delivery sets the initial parameters and peripheral mechanisms then regulate O₂ utilization within the bounds initially established by delivery mechanisms.