In conclusion, although hormonal changes are likely involvedin the pathogenesis of sarcopenia (Morley and Malmstrom, 2013),several unresolved queries remain about the relationship betweenendocrine function and muscle mitochondrial physiology. Studiesare also needed to identify possible differential effects of varioushormones on SSM and IFM. Lastly, further research is warrantedto determine if functional differences exist between systemic andlocal hormonal systems in advanced age, which could explain someof the controversial and disappointing results of hormonal supple-mentation in sarcopenic individuals.