This article discusses the "bidirectional"relationship between inflammatory bowel disease (IBD) and physical activity. Intestinal symptoms and extraintestinal manifestations of IBD negatively impact a patient's ability to participate in sports. IBD also impacts athletic performance via its effects on muscle mass, muscle function, bone density, and fatigue. Surveys of IBD patients consistently show that IBD interferes with athletic participation. While IBD negatively affects physical activity, there is growing evidence that physical activity can be beneficial for IBD patients. Prospective studies have revealed that structured physical activities may positively influence inflammatory markers, disease activity, muscle strength, bone density, fatigue, stress, anxiety, and quality of life. This suggests that physical activity may be a simple and safe adjuvant therapy for IBD patients. Future studies assessing the optimal activity regimen are warranted. Finally, a cohort of professional athletes with IBD are described for the first time-football players in the National Football League.