Keeping Your Stomach Steady

Douglas W. Stoddard M.D, M. Sport Med, Dip Sport Med, ES
Medical Director S.E.M.I (Sports and Exercise Medicine Institute)

We all hate stomach “issues” especially when we are competing.

A new “theory” is being promoted re: using low carb/high electrolyte drinks for hydration and only solid foods for major calorie sources. “Stomach friendly” is not just about solid food calorie sources.

Here is why.

1. Energy Density is a Huge Consideration:
Whether your drink has lower carbs, but you supplement with gels/bars, or vice versa, the most important concept is something called Energy Density i.e. how many calories are in your stomach at the same time, regardless of source. Spreading out your ingestion of carbs as part of a steady intake regardless of their source can be better tolerated than a larger hit of carbs all at the one time, but in the end, whichever the source of the calories you ingest isn’t near as important as the Energy Density at any given time of those calories in your stomach.

2. Types of Carbohydrates:
The resistant carbohydrates found in many solid bar options and certain forms of maltodextrin may cause gas and bloating in many individuals. We use 100% non resistant starch maltodextrin in our gels and FLY for this reason. Fructose, which is also found in many sport nutrition products/bars is also an irritating carbohydrate to many. Combo/Synergistic pathways of carbohydrate absorption i.e. glucose with fructose, may be helpful for some as ong as you can tolerate fructose….but MANY cannot. We prefer Sucrose because even though fructose is found in sucrose it behaves differently re GI irritation once cleaved off the glucose molecule in the small intestine…..versus being ingested by itself. Sucrose is a low irritation natural carbohydrate with a respectable Glycemic Index and this is why it is the sweetner of choice in eload endurance sport drink.

3.How to decrease your Energy Density: 
Gels are a larger “hit” of calories only if taken all at once. By simply taking smaller sips of your gel or FLY over a longer period of time, thus reducing the energy density of what is in your gut at any given time, gastrointestinal tolerability is increased. Some need to do this, and some don’t.

4. Acidity:
Other than lack of fructose content and energy density there are other properties of gels that improve their gastrointestinal tolerability such as lower Ph (lower acidity = less irritating)

5. Hydration and Sodium Balance:
A lot of G.I upset is Hydration and Sodium based. By the end of the race we are all dehydrated and sodium depleted and we are working at intensities not compatible with normal G.I function. It is no coincidence that these are the times we are likely to experience G.I upset.

6. Hydration and Sodium ALWAYS trump Calories:
If an athlete is diligent with hydration and sodium intake gut function would be that much better and less issues with gels would result. If one has to choose based on a gut unable to “do it all” sacrificing carb intake for better hydration and sodium balance is always the way to go.

7. Sweat testing:
In my clinical experience I have seen many endurance athletes who lose over 1.5L of fluid per hour. If they don’t stay on top of that along with adequate sodium intake they dont have much hope of absorbing carbs anway. If you are a major sweater it is worth taking a sweat test so that you are aware of exactly what you need to replace.
For those who lose less fluids and sodium, they will have more flexibility with carbohydrate intake.

8. Calculate Calories and fluid needed:
Know the fluid and calories you require for your event and intensity. Don’t just guess. Use our calculators here .