Proteolytic Gene Response to Exercise and Temperature

Abstract

Aging is characterized by a relative maintenance of myogenic activity and increased proteolytic activity resulting in a loss of muscle mass termed 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 (25.3 ± 5.0 y, 178.7 ± 6.1 cm, 86.8 ± 12.5 kg, 13.6 ± 6.6 % body fat, 1 RM Leg Press 139.0 ± 18.9 kg, 1 RM Leg Extension 67.2 ± 10.5 kg). The participants completed 4 sets of 8-12 repetitions of leg extension (LE) and leg press (LP) with each leg. Participants accomplished an average of 11 ± 1 reps at 76.6 ± 4.5% of 1 RM for LE and 9 ± 1 reps at 61.1 ± 6.5% of 1 RM for LP. ThermaZone Continuous Thermal Therapy System was used to heat the upper thigh of one leg and cool the upper thigh of the other leg. A muscle biopsy was taken from each leg pre- and 4 h post-exercise. Gene expression analysis will be done on the proteolytic genes of interest Atrogin 1, MuRF1, and FOXO3A. The mRNA analysis is nearing completion and will be finished for presentation at the research fair. This study will provide critical information for the development of novel temperature optimized exercise strategies that may help combat sarcopenia