Are your digestive issues flaring up with your training? Many athletes experience bloating, gas, cramping, or irregular bowel movements as their workout intensity increases, but few recognize what’s really driving these symptoms. In this blog post, we’ll explore the surprising connection between low energy availability (LEA) and IBS symptoms in athletes. You’ll learn how under-fueling can sabotage your digestion, why restrictive eating might be making things worse, and what practical steps you can take to heal your gut and perform your best.
Is Increased Training Causing IBS Symptoms & Digestive Distress?
Does an increase in training seem to also bring an increase in bloating, gas, constipation, diarrhea, stomach cramping, or other digestive distress? Gastrointestinal (GI) distress is a common yet overlooked issue among athletes and active individuals. These symptoms not only affect performance, but also diminish overall quality of life
As a specialist in RED-S, I believe the gut is one of the most crucial and underappreciated organs in athletic performance. Digestive discomfort isn’t just inconvenient; it may signal deeper imbalances rooted in energy availability.
While there may be other underlying causes contributing to these digestive issues, irritable bowel syndrome (IBS) is very common in individuals experiencing RED-S.
When Training Ramps Up, Energy Availability Often Drops
As training and therefore energy expenditure increases (and energy intake is not increased accordingly) the body goes into a state of low energy availability (LEA). LEA can then cause digestive dysfunction and IBS symptoms. In order to combat these IBS symptoms (bloating, gas, constipation, diarrhea, stomach cramping), athletes will often cut out foods or food groups that they predict may be “trigger” foods. Removing foods or food groups, especially if not substituting other equivalent foods in, can put the body into an even deeper state of LEA, causing worsened IBS symptoms… and the cycle continues.
Increased exercise → low energy availability
↑ ↓
cut out “trigger” foods ← IBS symptoms
How Does LEA Disrupt Gut Function?
Low energy availability impacts digestion in several key ways:
Delayed Gastric Emptying
This means food lingers in the stomach longer than it should, leading to early fullness, bloating, or distention.
Insufficient Digestive Enzymes
With insufficient energy, your body down-regulates enzyme production, resulting in poor nutrient absorption and increased food sensitivities.
Physiological Stress & Increased Gut Permeability (“Leaky Gut”)
Physiological stress caused by LEA can compromise the gut barrier, allowing unwanted particles into the bloodstream and contributing to inflammation and discomfort.
Dysfunctional Digestion
LEA may alter gut microbiota and slow intestinal movement, further contributing to IBS symptoms like stomach discomfort, bloating, gas, and reflux.
What Can You Do to Heal Your Gut & Avoid IBS Symptoms?
If these symptoms sound familiar, the most critical first step is to restore adequate energy availability. That means fueling your body consistently and intentionally, not just around workouts, but throughout the entire day.
Here’s a basic framework to support gut health and performance:
- Eat 3 balanced meals per day, emphasizing carbohydrates and protein
- Include 2–3 substantial snacks daily
- Prioritize pre and post-workout nutrition
- Avoid unnecessary food eliminations unless medically necessary
- Consider working with a sports dietitian trained in RED-S to assess your unique needs
Fueling to Feel and Perform Better
Digestive symptoms shouldn’t be accepted as “just part of training.” If you’re dealing with recurring bloating, cramping, or GI upset, it could be a sign your body is under-fueled. Addressing low energy availability is often the missing piece, not just for resolving IBS symptoms, but for optimizing performance, recovery, and long-term health.
Curious about working with me as a RED-S informed athlete provider and sports dietitian? Join the waitlist for my upcoming Athlete Nutrition Challenge, where I’ll help you master your fueling strategy and maximize your energy and recovery so you can feel your best no matter what you’re doing.
Want to become a RED-S informed provider and help support other athletes as they navigate energy, nutrition, and recovery? Join my RED-S Informed Provider Masterclass, where you’ll learn how to screen for, diagnose, prevent, and work with athletes experiencing RED-S.