Conclusions
One year of daily protein or carbohydrate supplementation neither seemed to alter the basal nor the protein-stimulated postprandial muscle protein synthesis rate in healthy older adults. In contrast to previous findings, no differences in basal protein synthesis rates between males and females were observed. The applied untargeted GC–MS methodology for measuring the skeletal muscle metabolome was efficient and robust and yielded a relatively high number of metabolites in comparison to the previous studies despite the use of only one analytical platform. The simple sample preparation protocol and the low amount of tissue required to perform the analysis make it a promising method for future investigation of the skeletal muscle metabolome.