Exercise against lower body negative pressure as a countermeasure for cardiovascular and musculoskeletal...

Exposure to lower body negative pressure (LBNP) with oral salt and water ingestion has been tested by astronauts as a countermeasure to prevent postflight orthostatic intolerance. Exercise is another countermeasure that astronauts commonly use during spaceflight to maintain musculoskeletal strength. We hypothesize that a novel combination of exercise and simultaneous exposure to lower body negative pressure during spaceflight will produce Earth-like musculoskeletal loads as well as cardiovascular stimuli to maintain adaptation to Earth's gravity. Results from recent studies indicate that leg exercise within a LBNP chamber against the suction force of 100 mmHg LBNP in horizontal-supine posture produces an equivalent, if not greater exercise stress compared to similar leg exercise in upright posture (without LBNP) against Earth's gravity. Therefore, the concept of LBNP combined with exercise may prove to be a low cost and low mass technique to stress the cardiovascular and the musculoskeletal systems simultaneously.