The strategic role of exercise devices in manned spaceflight

Exercise appears in various contexts during spaceflight. It serves as a key countermeasure against adverse physiological adaptation processes; it also plays a role in life sciences research as reference state or stimulus. Further aspects concern human factors, recreational activities, health monitoring and training for emergency egress and extra-vehicular activities. Current approaches rely on conventional ergometers, they add rather than integrate training programs, and they tend to disregard applications other than "countermeasures". Two major consequences are an appreciable impact on available crew-time and an unsolved problem: Exercise countermeasures use extrapolations of 1g-physiology in order to eliminate what physiologists would like to study: adaptation to weightlessness. New concepts and devices are required to reconcile such conflicting demands and to reduce time consumption for physical training. Key elements are an improved simulation of terrestrial locomotion and a recombination of work and physical exercise. The GRASIM device will be presented as an example for a new generation of multi-purpose "exercisers".