Subject Recruitment Twenty, runners (ages 18-50) were initially recruited via campus flyers, advertisements in the local paper and weekly sports guide. Participants who had medical histories including: heart disease, uncontrolled hypertension, diabetes, Crohn's Disease, irritable bowel syndrome, colitis, Celiac disease, inflammatory or autoimmune diseases or lactose intolerance were excluded from the study. All subjects were instructed to avoid all anti-inflammatory medications for at least 24 h prior to any testing activity. On the morning of the first visit, approved subjects had body composition measured by BodPod (Life Measurement, Inc., Concord, CA). Participants were asked to refrain from any heavy exercise for 48 hrs before the first visit. Subjects were given a 50 ml tube containing the 5 g lactulose and 2 g rhamnose sugar probe and instructed to drink the probe 4hrs after they have finished breakfast to determine baseline gut permeability. Subjects were given a urine collection container and instructed to collect all urine for 6 hrs after ingestion of the probe. Subjects were not to eat lunch until 1.5 hrs after drinking the sugar probe. After 6 hrs of urine collection, subjects returned to the test site and performed a running VO2 max test.