Exercise aids digestion and prevents constipation by stimulating the muscles of the bowel. It also improves symptoms of digestive diseases, such as irritable bowel syndrome, Crohn's disease, ulcerative colitis and celiac disease, according to Gastro Central. In fact, for digestive disease sufferers, the benefits of mild to moderate exercise multiply. Gentle stretching, such as that found with yoga and tai chi, reduces stress, improves immune function and helps control weight.
Exercise's role in preventing constipation is well-known, but overall benefits to health through good digestive system health are just beginning to be understood, according to WebMD. For example, a 2014 study finds a direct relationship between exercise and a variety of good gut bacteria, which make up a substantial part of the immune system. "Our findings indicate that exercise is another important factor in the relationship between the microbiota, host immunity and host metabolism, with diet playing an important role," the study authors wrote.
Too much exercise can overwhelm the digestive system in athletes, especially runners, causing nausea, vomiting, cramping, and diarrhea, explains the National Center for Biotechnology Information. Furthermore, WebMD explains that exercise just after a meal can cause indigestion or upset stomach, so one must plan exercise accordingly.