ABSTRACT
This book is focused principally on understanding V̇O2 kinetics in man. Where experiments on animals or animal muscles are presented within the various chapters, it is usually because the experimental modality is either not feasible, or cannot be conducted ethically, in humans. In contrast, this chapter adopts a comparative physiological approach that explores V̇O2 kinetics across extremely diverse species. As detailed in Chapter 15, V̇O2 kinetics are generally faster in fitter humans when compared with their sedentary or less-fit counterparts as judged by V̇O2 max. Moreover, after exercise training the speeding of V̇O2 kinetics in humans is associated with an increased V̇O2 max. These latter observations have been made over a relatively modest range (two- and three-fold, i.e. 20–70 ml · min−1 · kg−1) of V̇O2 max values. By comparison, judicious selection of the poorly aerobic lungless salamander (V̇O2 max <10 ml · min−1 · kg−1) and the Thoroughbred horse (Figure 5.1) or deer mouse (V̇O2 max 160–220 ml · min−1 · kg−1) permits analysis of this relationship over a much broader range of absolute and mass-specific V̇O2 max values (Figure 5.2). These species and several of intermediate V̇O2 max are examined in this chapter.
