[Space flight/bedrest immobilization and bone. In-flight exercise device to support a health of astronauts].

Despite the fact that astronauts living in the International Space Station (ISS) conduct daily two-hour intensive exercise programs to maintain their health, many health problems persist. These problems which include adverse effects of microgravity to bone, muscle and stamina, have not completely been countered. For example, bone mass reduction (about 1.6%/month at the neck of femur) , muscle atrophy (about 0.8%/day at the calf) , and exercise capacity reduction (about 10-20% decrease in the maximum oxygen uptake) have been reported. Interdisciplinary research approaches, such as various exercise countermeasures, a nutrition treatment, and medicine (bone absorption inhibitor) are employed in order to lower an astronaut's health risk and to promote productivity of work in space. This paper introduces the exercise equipment currently used in the ISS.