Figure 1.

Muscle fiber size (FCSA) and muscle fiber oxidative capacity ($\dot{\text{V}}$O_2max) are inversely related across animal species [r = −0.98, P < 0.001 (van der Laarse et al., 1998; van Wessel et al., 2010)] and in competitive cyclists [r = −0.50, P < 0.05 (van der Zwaard et al., 2018b)]. From left to right, animals include the shrew, mouse, rat, rabbit, human, African clawed frog (Xenopus laevis), and frog (Rana temporaria). Figure is created based on data from van der Laarse et al. (1998), van Wessel et al. (2010), van der Zwaard et al. (2018b).