Exercise may promote a healthy life, improving functional capacities. Little is known about the effects of physical activity in inflammatory bowel disease. Altered immunity is implicated in the pathogenesis of inflammatory bowel diseases. An acute, albeit transient acute immune response, follows heavy endurance exercise. Epidemiological data support the role of physical activity in lowering the risk of inflammatory bowel disease. Moderate physical exercise (60% VO2max) does not cause significant changes in symptoms, intestinal transit time, and permeability. Neutrophil function appears to be primed at basal conditions with significant activation after exercise. At present, mild exercise can be recommended to patients with quiescent inflammatory bowel disease as well as other chronic diseases such as rheumatoid arthritis, while caution is still needed for active disease patients. Patients with inflammatory bowel disease show a reduced exercise capacity after surgery, especially after extensive resections.