Skeletal muscle AdipoR1, AMPK and p-AMPK protein levels. Values of protein levels are expressed as % AU (arbitrary units), where control male rats were set as 100%. Data are expressed as the mean ± S.E.M of eight animals per group. ANOVA (p < 0.05): S sex effect, D HFD effect and NS non significant effect. Student's t-test (p < 0.05): a HFD vs control, b female vs male.