A recent study [13] reported that astronauts were in negative energy balance (~30 %) during a 17-day shuttle mission. Hypocaloric intake reduces HR, BP, and sympathetic activity [14–16], and we have documented reduced orthostatic tolerance following caloric restriction [17]. However, the impact of reduced caloric intake alone and in conjunction with microgravity adaptation on neural control of the cardiovascular system during static exercise or cold pressor is not known. Accordingly, the purpose of this study was to test the hypothesis that caloric restriction reduces the responses to cold pressor and static handgrip exercise, and to a greater extent when combined with bedrest.