One uncomfortable topic many runners avoid discussing is GI distress. Some lucky runners have "guts of steel," but most others experience abdominal discomfort (gas, bloating, constipation, or diarrhea) on a regular basis—and don't know what to do about it. A good first step is to keep a food and symptom log for a week. Don't be shy—write everything down, then examine your log for patterns, triggers, and problem foods. If you still can't figure out what's bothering you, bring the log to a Registered Sports Dietitian—he or she can likely find the cause, and you can put your GI distress behind you.