Everyday Ultra How to Train Your Gut for Ultramarathons: Avoid Stomach Issues, Bonking, and Fuel Like a Pro
Oct 31, 2025
Stomach issues are the leading cause of race dropouts in ultramarathons. Training your gut to handle carbs is essential for peak performance. A three-week protocol helps athletes increase carb intake while running. Discover how to identify your carb ceiling and adjust based on race intensity and distance. Joe also shares tips on hydration, liquid calories, and dealing with nausea during races. Plus, learn the psychology behind fueling when you're not hungry and find your go-to foods for race day.
AI Snips
Chapters
Transcript
Episode notes
Why Carbs Matter In Ultras
- Carbohydrates supply fast-burning energy that complements fat, so taking carbs during ultras prevents bonking.
- The more carbs you can tolerate, the more energy you can sustain during a race.
Three-Week Gut Training Protocol
- If you take less than 60 g carbs/hour, follow a three-week gut-training protocol taking carbs right before and 30 minutes into every run.
- This conditions digestion with reduced blood flow so you can handle higher carb loads in races.
Increase Carbs Gradually
- Bump your hourly carb target by 10 g on each long run and give each new level three long-run attempts to adapt.
- Track numbers, brands, and isolate variables to find your maximal tolerable carb rate.