Intestinal Adaptations of Male Rats to Endurance Exercise and Diet

Carbohydrate absorption may limit the benefits of carbohydrate ingestion during endurance exercise. Intestinal structural and functional adaptations were investigated in response to a vegan Daniel Fast diet (DF) or a Western Diet (WD), with or without endurance exercise training (DFE, DFS, WDE, WDS). Male Long-Evans rats (n = 28, aged 3-4 weeks) were assigned to the two diets and were either exercise trained by treadmill running or were sedentary for the 13 week intervention. Structural parameters significantly affected by diet (p \u3c0.05) include villus height, crypt depths, intestine length and mass. Exercise significantly affected the percentage of mucosa in the proximal small intestine and several histological measurements (p \u3c0.05). Functionally, WDE rats had higher proximal maltase activity (p = 0.04), but did not have higher rates of glucose uptake. A surprising finding is the intestine adapts to endurance exercise by reducing mass while maintaining carbohydrate digestion