Hypergravity resistance training on a human powered centrifuge

Abstract

Microgravity exposure results in muscular, cardiovascular, and skeletal deconditioning and loss of exercise capacity. The Space Cycle is a human powered centrifuge that can be configured for aerobic or resistance training to offer an integrative countermeasure to microgravity. Healthy male subjects performed 2 weeks of squat resistance training on the Space Cycle (SC, n=9) or using free weights (FW, n=9). Subjects completed 9 workouts, each consisting of 3 sets of squats at 70‐90% of individual 10 repetition maximum (10RM). SC subjects performed squats at 2.3 to 3.9 +Gz (measured at the feet) without additional weights. Biopsies were taken from the right vastus lateralis prior to, 4 h after, and 24 h after the first and last workout for evaluation of acute and chronic cellular responses to SC training. RNA was isolated from biopsy samples, cDNA prepared using RT‐PCR, and gene expression analyzed. Collagen IIIα1 expression was elevated two‐ to three‐fold after two weeks in both training groups. Importantly, no significant differences in collagen IIIα1 were seen when comparing FW and SC groups. Gene expression changes support the efficacy of the Space Cycle as a gravity‐independent resistance training device. Supported by NASA MA00403 and NIH M01 RR00827.