The goal of this basic research study is to investigate effect of resistance exercise on the quality of muscle proteins in younger and older men. The main question\[s\] it aims to answer \[is/are\]: whether there is a difference in muscle protein quality between younger and older adults and if resistance exercise training has a beneficial impact on the quality of muscle proteins? Participants will perform five bouts of unilateral leg press exercise during a 14 day period of deuterium oxide consumption and biopsy samples will be taken from both their exercised leg and non-exercised leg before and after the intervention period to enable the measurement of muscle protein abundances and turnover rates.