Exercise combined with resveratrol supplementation increased muscle mitochondrial biogenesis in obese mice undergoing weight loss. Mitochondrial DNA content in skeletal muscle was detected by RT–PCR (A). Western blot and quantitative analyses for PGC-1α were normalized by β-actin (B). Relative mRNA expression levels of PGC-1α and its downstream transcription factors in skeletal muscle were analyzed by RT–PCR (C). Relative mRNA levels of genes related to mitochondrial dynamics were analyzed by RT–PCR (D) in the skeletal muscle tissues of HFD-fed mice in the following four-week body weight loss-programs: control (Cont), exercise (Ex), resveratrol supplementation (Res), and exercise combined with resveratrol supplementation (Ex + Res). The values represent mean ± SEM (n = 6). P values were calculated by one-way ANOVA. *P < 0.05, and **P < 0.01 vs. Cont mice; #P < 0.05, and ##P < 0.01 vs. Ex mice; &P < 0.05, and &&P < 0.01 vs. Res mice.