A randomized, double-blind cross-over exercise trial was conducted with 14 runners on Utah State University campus. This population of 14 runners was selected from a larger population of 20 that was recruited to complete two initial trials. In two preliminary visits, the parameters necessary for conducting the experimental trial were determined. During the first visit, a baseline value was determined for gut permeability as well as aerobic capacity of runners. In the second visit the capacity to complete a run at 80% VO2max was tested and the effect of the exercise stress on gut permeability, plasma LPS and core temperature were measured.