Min-By-Min Respiratory Exchange and Oxygen Uptake Kinetics during Steady-State Exercise in Subjects of High and Low Max VO2

Publisher Website
Google Scholar
Abstract
In order to compare differences in min-by-min respiratory gas exchange and oxygen uptake kinetics during steady-state exercise 17 male subjects (mean age 22.5 yr ± 2.1) were divided into two groups (high max [Vdot]O2 group = 4.85 1/min ± .38, low max [Vdot]O2 group = 3.92 1/min ± .36, t = 5.04, P = <.001). Each subject completed, without work decrement, a submaximum work task of 720 kgm/min for 10 min duration. Both groups exhibited the same steady-state [Vdot]O2 during the submaximum exercise. However, there was a clear tendency for the high max [Vdot]O2 group to take up oxygen to steady-state at a faster rate. In addition, the min-by-min respiratory exchange ratios (R) for the high max [Vdot]O2 group were consistently lower, indicating less total energy production. It was concluded that the ability of the high max [Vdot]O2 group to complete the same amount of external work with less energy produced is indicative of an increased efficiency of some kind.