Q: I feel great in training, but I keep having to stop to use the bathroom during half-Ironman races. What can I do to avoid race-day pit stops?
A: There are many factors that can contribute to frequent Porta-Potty trips in endurance racing, most of which can be reduced or eliminated by a few simple nutritional changes:
Reduce your dietary fiber intake for the 1–3 days pre-race and 24 hours before big workouts.
Avoid sorbitol (found in sugar-free gums, candies and mints), which often causes gas, bloating and diarrhea.
Reduce your caffeine intake before and during your race.
Avoid spicy and fried foods for 24–48 hours pre-race (or important training days).
Steer clear of vitamin C supplements prior to training or competition.
Keep a food and symptom log to help you pinpoint your good and bad GI days and triggers.
Hydrate adequately while training and racing.
Ensure adequate sodium intake during long-course races. Endurance-specific sports drinks (e.g., Ironman Perform, Gatorade Endurance Formula) contain twice the sodium of regular ones.
Plan your calorie intake both in terms of grams per hour and grams every 15–20 minutes. Smaller doses of carbs every 15–20 minutes are much better received by your gut than large amounts every 45–60 min, especially the longer the race.
Try some solids on the bike (high-carb energy bars, bananas, quartered PB&J sandwiches) along with your liquid calories.
If you’re still having GI trouble, seek out a GI doc and a sports dietitian (RDN, CSSD) who can best assess your nutrition and save you lots of pit stops in the future.
Lauren Antonucci, R.D., is a board-certified specialist in sports dietetics, three-time Ironman finisher and the founding director of Nutrition Energy in New York City. If you’d like to have your nutrition question answered on this page, email firstname.lastname@example.org.