Fig. 4. (  A ) Graph representing mean (SD) arterial blood pressure at baseline and over the course the protocol with buffered hypercapnia compared to normocapnia. (  B ) Graph representing mean (SD) arterial lactate concentrations at baseline and over the course the protocol with buffered hypercapnia compared to normocapnia. * Significantly different from normocapnia (  P < 0.05, ANOVA) .