The 26.2-mile run on marathon day requires proper hydration and fueling both before and during the race. No matter how hard you train, if you don't treat your body properly on race day, you may face stomach cramps, nausea, vomiting or diarrhea. Any of the potential stomach problems make completing the marathon more difficult or impossible. Knowing your own body and what it can handle is key to successfully avoiding stomach problems during a marathon.
Schedule your marathon training runs at a similar time as the actual race. This gets your body accustomed to running at that time. You are also better able to determine how to eat before the race at that time of day.
Test any foods or fueling sources such as gels or candy on a long run before the marathon. Never try a new food that hasn't been tested during a long training run, as you may experience unexpected stomach problems.
Avoid high-fat foods in the days leading up to the race. The fats can cause digestive difficulty.
Eat breakfast about two hours before the marathon begins, combining carbohydrates and protein for energy based on your training run meals. Eating a few hours before the race reduces cramping or diarrhea.
Hydrate leading up to the race to prevent dehydration that can cause cramping. Drink 8 oz. of a sports drink before the race starts, to give the carbs enough time to help with your energy levels during the race. Waiting until later in the race when you're getting tired doesn't allow enough time for the drink to work.
Use the restroom right before the race. Having a bowel movement before the race may prevent cramps or diarrhea during your run. You also reduce the chances of needing to stop along the race route for a bowel movement.
Drink water with any fueling gels you use during the marathon. The water helps dilute the sugar in the gels, which can cause stomach problems. Diluting sports drinks with water also helps avoid intestinal issues.
Eat real food within an hour of the race's end. This prevents stomach pains after the marathon. Real food may also help relieve stomach problems you may experience from the marathon.