MTOR Signaling Pathway Associated With Percent Change In Skeletal Muscle Strength Following Resistance Exercise Training

Abstract

PURPOSE: To examine the association of genetic variations among four single nucleotide polymorphisms (SNPs) of the AKT1 gene and three SNPs of the AMPKa2 gene with percent change in muscle strength following a resistance exercise training (RET) program while controlling for the effects of age, gender, and RET history. These genes are part of the mTOR signaling pathway, which has been shown to be an important mediator of protein synthesis in adult animals. METHODS: Participants were young men and women age 18-31 years, from the Molecular Epidemiology of Resistance Exercise Training study who completed 10 weeks of RET. Participants trained 3 days per week at 75% of one repetition maximum, performing 3 sets (6-10 repetitions) of 13 resistance exercises: lateral pull down, abdominal crunch, shoulder press, seated row, leg extension, triceps extension, leg press, calf raises, leg curl, arm curl, back extension, chest press, and incline chest press. Statistical analyses were performed using univariate analysis of variance with a least significant difference post-hoc test. RESULTS: Data are presented as percent change in one repetition maximum marginal means ± standard error. An AKT1 SNP, rs3001371 (CC 22.5 ± 2.7%, n = 52, CT 30.3 ± 2.9%, n = 44, TT 18.6 ± 4.2%, n = 22, P = 0.05), and an AMPKa2 SNP, rs1418442 (AA 25.0 ± 3.5%, n = 32, AG 27.6 ± 2.5%, n = 60, GG 14.3 ± 4.4%, n = 20, P = 0.04), were associated with percent change in leg curl one repetition maximum following RET. CONCLUSION: The results of this investigation suggest that the mTOR signaling pathway is associated with variations in the individual response of skeletal muscle to standardized RET.