The Role of Hydration on Exercise Performance - ODIN

During exercise in the heat, there is a need to replenish fluids in order to avoid
dehydration and decrease the risk for heat illness. What drives this urge to drink is the
thirst mechanism. Following ingestion of fluids, there is an inhibition of thirst before
there is a replenishing of fluids. However, there is little scientific evidence of where
thirst is inhibited, if this thirst inhibition is augmented by exercise and how thirst
itself influence exercise performance. Further, during rehydration studies, it is very
difficult to successfully blind a subject to their drinking/hydration protocol. Previous
studies that have blinded a subject to their drinking have used various methods such as
intravenous fluid administration and/or nasogastric tubes. Therefore, the purpose of this
research is to examine the mechanistic roles thirst inhibition plays while exercising in the
heat while undergoing intravenous fluid administration. Specific attention will be directed
to the cardiovascular and thermoregulatory function of the individuals. All blood,
cardiovascular, thermoregulatory, and perceptual measures are shown in the diagram below.