# Nutritional strategies to minimize GI issues

Saturday newsletter, sent March 4, 2026 by Daniel Rowland.
Web page: https://saturday.fit/newsletter/2026-03-04-nutritional-strategies-to-minimize-gi-issues/
Prices and features may have changed since this was sent.

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## · Minimizing gut issues ·

Hi Saturday Morning Fan,

This week, we are looking at a recent systematic review on how to reduce gastrointestinal (GI) symptoms during endurance exercise. Gut problems are one of the most common issues to effective fueling in long training sessions and races. They can limit intake, reduce performance, and, in some cases, end a race early.

This paper summarizes a wide range of research and provides practical guidance for improving gut tolerance.

**Why GI symptoms matter**

During prolonged exercise, blood flow is redirected away from the digestive system toward working muscles and the skin. At the same time, athletes are consuming large amounts of carbohydrate and fluid.

This combination places significant stress on the gut. As a result, symptoms such as nausea, bloating, cramps, reflux, and diarrhea are common, especially in sessions longer than 2h.

When fueling becomes uncomfortable, athletes often under-eat, which then compromises performance.

**Key findings from the review**

The main conclusions of the paper can be summarized as follows:

High carbohydrate intake increases GI risk when it exceeds individual absorption capacity.

Using multiple transportable carbohydrates, such as glucose and fructose, improves absorption and reduces symptoms compared to single-source products.

Regularly practicing race-like fueling in training improves tolerance and reduces discomfort. “Gut training” is one of the most effective long-term strategies.

Both dehydration and overhydration increase GI symptoms. Excessive intake of plain water is particularly associated with bloating and discomfort.

Low-fiber, low-fat, and low-residue diets before long sessions reduce symptoms. High fiber, high fat, and sugar alcohols increase risk.

Liquid and semi-solid carbohydrate sources are generally better tolerated than solid foods during exercise.

Large individual differences exist. Some athletes tolerate very high intakes, while others develop symptoms at moderate levels.

**What does this mean for you?**

First, practice your race fueling in training. Use long sessions to test carbohydrate type, dose, and timing. This is the most reliable way to reduce GI problems.

Second, aim for the highest intake you can tolerate comfortably, not the highest intake suggested by generic guidelines. More is not always better if it leads to symptoms.

Third, use well-formulated products with multiple carbohydrate sources, such as Speed Nectar, to support absorption and reduce gut stress.

Fourth, manage hydration carefully. Avoid both chronic under-drinking and aggressive over-drinking. Adjust intake based on conditions and sweat losses.

**The bottom line**

Saturdayis designed to help with all of these issues. Take the time to set up your profile carefully, then use the app regularly during training to ensure that you both become accustomed to your fueling strategy and you learn what works best for you.

_Mlinaric J, Mohorko N. Nutritional strategies for minimizing gastrointestinal symptoms during endurance exercise: systematic review of the literature. J Int Soc Sports Nutr. 2025 Dec;22(1):2529910. doi: 10.1080/15502783.2025.2529910. Epub 2025 Jul 11. PMID: 40650376; PMCID: PMC12258207._

Have any thoughts, comments, or questions that you'd like to share? Please [email](mailto:info@saturdaymorning.fit) us anytime!

Daniel

_Endurance Athlete, Coach, and Saturday Customer Support._