The Effects Of Hypergravity Resistance Training On Cytoskeletal Mrna Levels And Translational Markers

Artificial gravity has been postulated to represent the most logical choice for a countermeasure to microgravity, and, yet few studies have examined its potential. PURPOSE: Given this background, the primary goal of this study was to contrast the effects (1) of a free weight 10 RM weight training program and (2) those of a hypergravity resistance training program. METHODS: Eighteen subjects were randomly assigned to two different groups: 1) those that performed a 10 RM resistance training program four times per wk for two wks using free weights (FW group); and 2) those that trained using a hypergravity 10 RM training program (HG group). Muscle biopsies of the vastus lateralis were taken pre and post training, and the muscles were analyzed for key markers of increased transcription and translation. RESULTS: Both training programs produced rapid increases (i.e., within 4 hrs of the first training session) in phosphorylation of a key translational marker, p70s6k. The magnitude of phosphorylation in both groups was similar. There were no differences in the level of p70s6k phosphorylation pre and post training. Additionally, we looked at mRNA levels of both actin and myosin. Both groups exhibited similar increases in the mRNA level of actin, while changes in total myosin mRNA were not evident for either group. CONCLUSION: Collectively, the responses observed in this study are consistent with the hypothesis that artificial gravity can be used to produce muscle adaptations similar to those produced by free weight resistance training. This finding supports the concept that artificial gravity has the potential to serve as an important countermeasure to microgravity. Supported by the National Space Biomedical Research Institute through NASA MA00403 (VJC), NIH 2T32AR047752 (VJC), and NIH M01 RR00827.