The purpose of this study was to identify and compare the effects of ingesting either water or 6% solution of carbohydrates, electrolytes, and water on hydration status during simulated military road marching in hot environmental conditions. Five volunteer male subjects completed two 60 minute experimental trials exercising at a high intensity (RER .90-.95) in an improvised environmental chamber (29.7 + or - .18oC, 11.3 + or - 2.13% relative humidity) in full army combat uniform carrying 18.18kg of equipment. Random assignment of either water or solution was completed prior to trial 1, and consumption of the unselected protocol was completed during trial 2. Variables monitored included heart rate, core temperature, stroke volume, bodyweight loss, blood pressure, and hematocrit. Statistical analysis using MANOVA resulted in no statistically significant differences between trials for these variables. Post 30min data demonstrate consistent trends towards water being more effective at maintaining physiological markers of hydration compared to 6% solution during 60 minutes of intense exercise in high heat
