Physiological Effects Of Spaceflight/Unloading And The Mitigating Effects Of Flyweel-Based Resistive Exercise

The deleterious effects of spaceflight encompass numerous physiological effects that collectively undermine long-term goals of manned round-trip missions to Mars. Perhaps the greatest losses are to the human musculoskeletal system from limited mechanical/load-bearing activity. In-flight countermeasures seek to reduce physiological losses, the restoration of mechanical/load-bearing activity in μg is achieved with flywheel-based resistive exercise hardware. Research with spaceflight analogs showed exercise done with flywheel-based devices abated muscle mass and strength losses with modest increases in net energy costs. This led to the installment of flywheel-based hardware on The International Space Station. To date, exercise with flywheel-based hardware has reduced musculoskeletal losses, with greater success achieved for muscle-, as compared to bone-based, outcomes. More success as a bone loss countermeasure may be achieved with exercise hardware that imparts higher strain rates to the engaged musculoskeleton.