Weight Loss in Men in Space

Science  03 Feb 1967:
Vol. 155, Issue 3762, pp. 558-560
DOI: 10.1126/science.155.3762.558


Men returning from orbital flights have lost from 2 to 6 percent of their body weights. Similar losses occur during simulated weightlessness; blood normally pooled in dependent parts returns to the circulation, increasing central blood volume and causing excretion of water which is not replaced during flight.