[Tailward acceleration tolerance of middle-aged persons before and after a 7-day immersion].

Before and after 7-day immersion 6 healthy male test subjects, aged 41 to 49, were exposed to +3 GZ for 60 sec in a centrifuge with an arm of 7.25 m. The runs were repeated 12 times. The test subjects well tolerated the exposure before and after immersion. However, after immersion the physiological systems functioned in a more stressful manner than prior to immersion. This can be attributed to the deconditioning caused by simulated weightlessness. The comparison of the experimental findings with the literature data gives evidence that the pattern and level of physiological changes induced by an exposure to +3 GZ for 60 sec in the test subjects, aged 41 to 49, do not differ significantly from those in younger (aged 23 to 36) people.