Fueling for Performance Without GI Distress: A Guide for Active Women
Gastrointestinal (GI) issues are more common in women than in men, particularly during exercise. These issues can include bloating, cramping, diarrhea, urgency, and delayed gastric emptying. Multiple factors contribute, including hormonal fluctuations and slower gut motility in females.
Understanding how exercise impacts the digestive system—and how to fuel and hydrate effectively—can help reduce discomfort and improve performance.
Why GI Distress Happens During Exercise
During intense or prolonged exercise, the body redirects blood flow away from the gut and toward the working muscles. This decrease in gut blood flow (intestinal hypoxia) triggers changes such as:
- Reduced absorption of fluids and nutrients
- Increased risk for diarrhea or cramping
- Slower gastric emptying (“sloshing” sensation)
- In some cases, intestinal bleeding
Dehydration can further compound these effects by reducing blood volume and increasing gut permeability.
Fueling Based on Duration and Intensity
For light activities such as walking or low-intensity strength training, detailed fueling strategies aren’t typically needed. However, for endurance training or high-intensity efforts, strategic fueling becomes essential.
Research shows that nearly 45–50% of endurance athletes experience some form of GI symptoms. These become more likely during long training sessions or races, especially if the digestive system is unaccustomed to handling food or fluid during exertion.
Hydration: The First Priority
Hydration should always come first. Symptoms that feel like “bonking” are often actually due to dehydration—not lack of fuel. Dehydration thickens the blood and makes nutrient delivery and thermoregulation more difficult, increasing fatigue and GI risk.
For more guidance, refer to: Hydration Is Power: Harness Yours (linked in your library).
How Much Fuel Is Enough?
Women generally rely more on blood glucose than stored glycogen during exercise, making steady fueling more important. While elite male athletes may absorb up to 78 grams of carbs/hour, this is rarely achievable or necessary for most women.
Instead, a better range for most active women is:
- Running/jostling activities: 0.9–1.15 food calories per lb. of body weight per hour (2–2.5 kcal/kg)
- Cycling or low-impact endurance sports: 1.3–1.6 food calories per lb. of body weight per hour (3–3.5 kcal/kg)
Aim for a mix of carbohydrates, proteins, and fats to avoid overwhelming a single digestive pathway. Excess carbohydrate alone may lead to bloating, gas, and GI upset.
Training Your Gut
Just like muscles adapt to training, your gut can adapt too. Practice eating and drinking during training so your digestive system learns to tolerate fuel under stress. Use familiar, easily digestible foods during longer workouts and races.
Caution with Energy Gels
Energy gels, while convenient, are highly concentrated carbohydrate sources—often 73% sugar solution. When not properly diluted with water, they can slow gastric emptying and even draw water into the gut, potentially causing dehydration and GI distress.
Many gels use maltodextrin, which can overload the intestinal transporters and delay absorption. Even isotonic gels can create similar problems if consumed without proper hydration or in high volumes.
If a quick energy boost is needed, glucose tablets may be a better tolerated alternative.
Recipe: Easy, Digestible Fuel – Salty Balls
These are a balanced, gut-friendly option for longer sessions:
Ingredients:
- ½ cup natural nut butter
- ⅓ cup brown rice syrup
- ½ tsp vanilla
- Dash of cinnamon
- 1 tsp instant espresso (optional)
- ½ cup whey protein isolate
- ¼ cup crisped rice cereal or oats
- Sprinkle of salt
Instructions:
- Heat nut butter, brown rice syrup, vanilla, and cinnamon in a microwave-safe bowl for ~1 minute, until bubbly.
- Stir in protein powder and cereal/oats.
- Mix well and shape into ~10 balls.
- Top with a pinch of salt and freeze until use. (Approx. 140 kcal/ball)
Key Takeaways:
- GI symptoms are common in active women but manageable with proper strategy.
- Start with hydration, and match your fuel to the intensity and duration of activity.
- Use mixed macronutrients, and train your gut like you train your muscles.
- Avoid over-reliance on concentrated gels and opt for whole-food options when possible.
For more personalized fueling strategies, explore the Nutrition for Performance section of the membership library or reach out through your coaching portal.