PURPOSE: Protein recommendations pre-running have yet to be established and will need to consider performance responses as well as the potential for exercise-induced gastrointestinal symptoms. The purpose of this study was to examine the impact of a high protein (HP) shake consisting of 0.4 g/kg body weight (BW) protein vs. a low protein shake (LP) 0.15 g/kg BW protein pre-run on glucose, gut fullness, and perceived exertion. METHODS: Five (n=2 male) endurance trained runners were administered a HP or LP shake one hour prior to a 10 km run in a randomized cross-over design. Carbohydrate and water intakes remained consistent across trials. Blood glucose was measured at fasting, 30, and 60 minutes post-shake and post-run using a glucose meter. Perceived exertion was measured using Borg’s scale. Exercise induced gastrointestinal symptoms were measured at fasting, pre-run and post-run using a 10-point questionnaire. Gut fullness was measured using a visual analogue scale at fasting, 15, 30, 60 minutes post-shake and post-run. RESULTS: Blood glucose peaked at 30 minutes post-shake and there was no difference between the HP and LP shakes. There was a significant interaction between time and shake (p=0.044), however no main effect of time or shake. There was no difference in perceived exertion between the two interventions. Gut fullness changed over time (p=0.005), however, was not affected by the composition of the shake. There was no difference in the number of exercise-induced gastrointestinal symptoms experienced on the HP and LP shakes. CONCLUSION: The results from this pilot study suggest that the inclusion protein in the pre-run meal is feasible and provides support for a fully powered trial. Supported by Mount Royal University Innovation Grant