A. Daily metabolic rates of major organs and tissues. Shown values are from human subjects. Data is from Wang et al., 2010 [215]. B. Fold changes in oxygen consumption rates of different tissues in different species. Each data point shows the fold change in oxygen consumption determined by distinct studies performed in liver [15–20], kidney [21, 22], heart [23–32], and skeletal muscle [33–36]. All shown measurements were carried out with healthy tissues of wild-type animals under similar, physiologically relevant basal and strenuous activities. The indicated weight (in Kg) is the total body weight.