Aging is characterized by a relative maintenance of myogenic activity and increased proteolytic activity resulting in a loss of muscle mass termed sarcopenia. Little is known about the impact of muscle temperature on the regulation of proteolysis associated with sarcopenia. The purpose of this study is to determine the impact of local muscle heating and cooling on proteolytic gene response following resistance exercise. Recreationally resistance trained male participants will complete 4 sets of 8-12 repetitions of leg extension and leg press at 80% of their 1-repetition maximum for each exercise with two minutes recovery between sets. A ThermaZone Continuous Thermal Therapy System will be used to heat the upper thigh of one leg and cool the upper thigh of the other leg. A muscle biopsy will be taken on one leg (randomized) pre exercise and both legs 4 hours post exercise while femoral blood flow will be measured on both legs pre, post, and 4 hours post exercise. Gene expression analysis will be done on the proteolytic genes of interest Atrogin 1, MuRF1, and FOXO3A. This study will provide critical information for the development of novel temperature optimized exercise strategies that may help combat sarcopenia
