The Runner’s World Guide to Nutrition and Fueling: The Runner’s Gut

Upset stomachs and the sudden need for a bathroom—now!—happen to every runner. The struggle is real, and often comes at the most inconvenient times. Fortunately, run coach Mireille Siné and registered dietitians Amy Goblirsch and Kristy Baumann offer advice on how to prevent digestive problems in The Runner’s World Guide to Nutrition and Fueling, a Runner’s World+ exclusive program.The experts will offer strategies to train your stomach with the right fuel for long runs, what to do if nausea or the need for a bathroom occurs midrun, and the role proper hydration plays in keeping your digestive system happy and healthy.If you are nervous about long runs and your digestion, then this video program will help you feel confident about unexpected emergencies on the road.What You’ll LearnIn The Runner’s World Guide to Nutrition and Fueling, we’ll teach you:Why the process of running can upset your stomachWhat to do if digestion issues arise midrun How to better train your stomach for long runs and racesNavigating sensitive stomach issuesThe role hydration plays in your overall GI healthWatch VideoGo Deeper Just like runners have different paces and a million other personal quirks (shoes, outfits, type of music), they also each have their own idiosyncratic digestive systems. Some distance runners drink coffee and eat peanut butter before a race, while others have to perfectly time their caffeine and fat consumption to keep their stomachs and the rest of their digestive systems happy and calm.The best way to be confident that unexpected visits to the bathroom won’t interrupt your long race or run is to train your stomach throughout your training plan and learn which fuels work best for you.“Just like you train your legs to run three miles or to run 26.2 miles, you have to train your stomach because your stomach is a muscle.”—Kristy Baumann, registered dietitianYou don’t want to, as many runners do, just take Imodium in order to avoid runner’s trots. Instead, you need to take the time to find the underlying reasons about why you might be having frequent GI issues and be confident that you, maybe with the help of a nutritionist, can solve them. As our experts say, there are strategies to help prevent surprises.Understand the Potential Causes of an Upset StomachEven if you have a stomach of steel, running can cause unexpected problems to your digestive system. When you run, blood is diverted from your stomach to your working limbs, and that can throw the whole thing out of whack in terms of the rate at which food moves through the gastrointestinal tract.Also, the running itself can jostle what’s inside your body and cause some queasiness and other issues.Underfueling, and fueling improperly with too much fat, for example, can also make your runs unpleasant. Some common foods and drinks that are at the root of runner’s trots are those with a higher proportion of fat or protein than carbs, such as:Dairy and meatCaffeine​Artificial sweeteners​High-fiber foodsTrain Your Stomach and Intestinal TractTo solve the potential digestion problems on long runs, coaches and dietitians recommend practicing your long run fuel intake while you train. Also, because the best fueling strategy is personal, keep a food journal, noting exactly what you ate the night before, the morning of, and after a long run. Include the food, the amount, and any gels or electrolytes you add. Try to keep track of your water intake, too.Part of your training includes thinking about the timing of your carb, water, and electrolyte intake.Before a race: aim for at least 1 gram of carbs per 2 pounds of body weight (lbs).If fueling your runs is brand new to you, start with small amounts of food, water, and electrolytes (which may all come in one package if you choose something like a gel). Try to eat three to four hours before a race lasting two hours or more.Over time, start adding fuel and hydration during your runs (in small quantities) until you determine your perfect mix.Pro runners don’t leave their fueling to chance, and you shouldn’t either. Not because you’re chasing their numbers, but because you don’t want an upset stomach or an unexpected trip to the bathroom to ruin your race day experience.What to Do If You Feel Queasy During a RunBaumann and Goblirsch have a few tips to help you survive queasiness, nausea, or runner’s trots. First, drink a little water (without electrolytes) and maybe eat a mint or two (mint is a stomach-soother). That’s what Goblirsch does during her ultras.Meanwhile, try slowing your pace a little to see if backing away from intense movement helps everything settle.Feeling queasy on a run? Drink some water, eat a mint, or slow your pace.Also, as always, respect the conditions. Heat, altitude, and other factors can affect how you feel during a run, and if it’s your stomach and intestinal tract that reacts, you need to prepare for those possibilities.Got questions about performance nutrition?Fueling can be the difference between a run that feels strong and one that falls apart.Through conversations with leading sports dietitians, nutrition experts, and coaches, the Runner’s World Guide to Nutrition and Fueling turns the science of sports nutrition into practical, runner-friendly strategies for everyday training and racing. Available exclusively to Runner’s World+ members on September 10!Donna Raskin has had a long career as a health and fitness writer and editor of books and magazine articles. A certified run coach who has practiced yoga for many years, she also loves to lift weights, dance, and go for long walks with her hound dog, Dolly.