PPARGC1A and overnutrition: Stability of PGC-1α hasbeen shown to be driven by both acetylation as well as phosphorylation [42,43].Stability and activity of PGC-1α is enhanced by phosphorylation by p38MAPK [43] which again raises the interesting issue of the role of the MAPKs inboth sarcopenia and in responses to overnutrition.