Avoiding Physical Atrophy In Protracted Weightlessness

Abstract

Gravity is only one possibility among others to build up a counterforce for the development of muscular tension and for the performance of muscular work. Muscular tension can be likewise developed under weightless conditions between fixed points inside or outside the body. Work can be done as well against one fixed and one elastic point or against friction. Thus even the smallest room will allow the arrangement of a sufficient trainging system. It has been shown recently that one daily maximum contraction of 5 sec is enough to keep a muscle strong and enduring enough for static work. In order to maintain a high capability for dynamic work, muscles have to work daily for about 1/2 hour as hard as possible. To keep the heart fit and the hemoglobin-content of the blood high for short éxtreme stress-situations, it is sufficient to raise the pulserate once a day up to 100 - 200 beats/min for about 30 sec by exhausting work. This is usually achieved by standing-running under the influence of gravity. Under weightless conditions cranking seems to be the best solution for physiological and technical reasons.