Anthropometric changes in male subjects on exposure to 24 hours of simulated microgravity

Objectives Condition of weightlessness remains one of the primary environmental concerns of space flight. A variety of ground-based studies using analogs of weightlessness have been carried out to investigate the effects of weightlessness on the human body. Significant data are available on anthropometric changes that occur on exposure to microgravity. However, there has been scanty data on the anthropometric changes that occur after 24 h of exposure to microgravity. This study was designed to assess the changes in anthropometric parameters of human male subjects on exposure to 24 h of microgravity using dry supine immersion (DSI) which is one of the ground-based simulators of microgravity. Material and Methods A total of 10 volunteer subjects were exposed to 24 h of microgravity that was simulated by DSI. Anthropometric parameters such as weight, supine body length, body mass index (BMI), leg girth, and calf girth were measured pre and post-exposure to simulated microgravity. The results were collated and analyzed using a paired student t -test. Results The results showed a statistically significant increase in the supine body length (effect size = 0.096, P = 0.009). The study also showed a statistically significant decrease in the weight (effect size = −0.07, P = 0.0001), BMI (effect size = −0.15, P = 0.0006), calf girth (effect size = −0.59, P = 0.0001), and thigh girth (effect size = −0.33, P = 0.016). Conclusion A significant increase in supine body length by a mean value of 0.67 cm was noted after 24 h of exposure to simulated microgravity. A significant reduction in weight, calf girth, and thigh girth by 880 g, 1.33 cm, and 1.18 cm was noted after 24 h of exposure to simulated microgravity.