* significantly different from all groups (p<0.01);^† significantly different from each other (p<0.05); ^a significantly different from 4 and 8 mL (p<0.05); ^b significantly different from 1 and 2 mL (p<0.05); Data presented as mean ± SEM with n=6/group, except qO₂ and qCO₂ with n=3/group; † ratio of 2 (Y_L/G) indicates 100% anaerobic metabolism.