Low-dose T3 improves the bed rest model of simulated weightlessness in men and women

Research was conducted to test the hypothesis that low-dose 3,5,3'-triiodothyronine (T3) administration during prolonged bed rest enhances the ground-based model of spaceflight. The effects of T3 on body composition, protein metabolism, metabolic rate, insulin sensitivity and secretion, and growth hormone secretion were compared. Findings showed that addition of low-dose T3 to the bed rest model of muscle unloading enhances the ground-based simulation of spaceflight and reveals several significant gender differences.