For the determination of the mRNA expression of PGC1α and GAPDH, total RNA was extracted from 20–30 mg muscle using procedures we have previously described (3 (link)). The isolated RNA was used to perform cDNA synthesis using the ABI High Capacity cDNA Reverse Transcription kit (Thermo Fisher Scientific Inc., Waltham, MA), and real-time PCR was performed on an Applied Biosystems 7900HT Fast Real-Time PCR System (Thermo Fisher Scientific Inc., Waltham, MA) using predesigned TaqMan® gene expression assays (probe/primer sets) for PGC1α (assay Hs00173304_m1) and GAPDH (assay Hs02786624_g1) (Thermo Fisher Scientific Inc., Waltham, MA).