Figure 7. Difference in blood cortisol concentration. Bars are mean ± standard error. CON and white bar: control group; RS and striped pattern bar: restraint stress group; RSVE and black bar: restraint stress and voluntary exercise group. a: significantly different from CON, p < 0.05; b: significantly different form RS, p < 0.05; c: significantly different from RSVE, p < 0.05.