[Effect of periodic "head-foot" G-forces in a short-radius centrifuge on human cardiovascular system responses]

During 3- and 6-day immersion studies test subjects were two or three times a day (60 min each time) exposed to head-to-feet acceleration of 1-2 G in a 2 m arm centrifuge. In 297 runs cardiovascular reactions were compared with respect to their adaptation or cumulation. The results showed that the principle of periodic application of acceleration in a short-arm centrifuge as a countermeasure against cardiovascular deconditioning can be complemented by the principle of cyclic exposures. The study demonstrated that 3-day cycles including 60 min exposures to 1-2 Gz twice a day were most efficient.