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Why Does My Stomach Hurt When I Run? Causes & Solutions

Published By: Dr. Jeffrey Mark
Date: March 29, 2024

Many runners experience stomach discomfort during high-intensity exercise, which can range from mild pain to severe nausea, affecting their performance and overall health. Understanding why this happens is crucial for athletes to manage and prevent digestive issues during their training.

This article explores the various factors that contribute to stomach pain during running, from the physiological impact of exercise on digestion to the importance of post-run nutrition and the role of core muscles.

Why does my stomach hurt when I run?

High-intensity running diverts blood away from the digestive system to muscles, lungs, and heart. This reduced blood flow impairs digestion, leading to nausea, cramping, and discomfort when consuming food/liquids during the run.

Key Takeaways:

  • High-intensity exercise can strain the digestive system, leading to discomfort and, in severe cases, forcing athletes to abandon their races.
  • Heat and dehydration during exercise can worsen digestive symptoms by diverting blood flow from internal organs and thickening the blood.
  • Heavy breathing and the body's stress response during intense workouts can cause gastrointestinal issues, including bloating and nausea.
  • Strengthening core muscles is essential for digestive health, as they support the body and protect internal organs, with weakness potentially linked to muscle diseases.
  • Proper post-run nutrition is key to muscle and stomach recovery, helping to replenish glycogen stores, repair muscles, and balance electrolytes and minerals.

Understanding the Impact of High-Intensity Exercise on Digestion


Impact of High-Intensity Exercise on Digestion

The Struggle of Digestive Organs During Strenuous Workouts

When I push my body to the limit during a run, I've noticed that my stomach often protests. It's not just me; many athletes report nausea and severe stomach pain during intense workouts, sometimes to the point where they can't even hydrate properly.

Our digestive system isn't built for high-intensity exercise, which can lead to discomfort and even force some to abandon their races.

During a less strenuous workout, my body manages to distribute blood flow to support all systems, including digestion. However, as the intensity ramps up, my muscles, lungs, and heart demand more blood, leaving my digestive system with a reduced supply.

This shift can make it challenging to process any food or water I consume while running.

Here's a simple breakdown of how my body prioritizes blood flow during exercise:

  • Low-Intensity Workout: Balanced blood flow to muscles and digestive system.
  • Moderate-Intensity Workout: Increased blood flow to muscles, slightly reduced to the digestive system.
  • High-Intensity Workout: Significant blood flow to muscles, lungs, and heart, with the digestive system getting the short end of the stick.

Understanding this, I've learned that it's not just about training my muscles for endurance but also conditioning my digestive system to cope with the demands of a long race.

Heat and Dehydration: Aggravators of Digestive Discomfort

When I run, the heat and dehydration can really take a toll on my digestive system. As my body temperature climbs, my blood is redirected from my internal organs to my skin, which is my body's way of trying to cool down. This shift can lead to a decrease in digestive function, making me feel uncomfortable.

Dehydration thickens my blood, which slows its circulation. This can exacerbate any digestive issues I'm already experiencing. It's crucial to stay hydrated, not just for my overall health, but to keep my digestive system functioning smoothly.

Here are a few tips I've learned to help manage these issues:

  • Stay Hydrated: Drink plenty of water before, during, and after running.
  • Monitor Electrolytes: Replace lost salts and minerals with an electrolyte solution or sports drink.
  • Dress Appropriately: Wear breathable clothing to help manage body temperature.
  • Pace Yourself: Avoid pushing too hard in extreme heat to reduce the risk of overheating.

I've found that by paying attention to these factors, I can minimize digestive discomfort and focus on enjoying my run.

Recommended Article: The Right Way To Heal Your Gut Health

The Role of Heavy Breathing and Stress Response in GI Issues

When I run, my breathing naturally becomes more intense. This isn't just about getting more oxygen to my muscles; it can also lead to swallowing air, which then accumulates in my gastrointestinal (GI) tract.

This can make me feel bloated and uncomfortable, a sensation that's far from welcome when I'm trying to focus on my pace and endurance.

The stress response from high-intensity exercise is another factor that can upset my stomach. It's not just about physical stress, but also the psychological impact of pushing my limits. This response can slow down my digestive system, leading to bloating and discomfort.

If I'm not accustomed to the intensity, my cortisol levels might spike, potentially causing increased blood pressure and fluid retention.

Here's a quick list of how stress and heavy breathing affect my GI health during a run:

  • Swallowed air leads to bloating.
  • Slowed digestion due to stress response.
  • Potential spike in cortisol levels.
  • Possible increase in blood pressure and fluid retention.

While these issues can be a nuisance, it's important to remember that exercise, including running, has numerous benefits for my mental health and overall well-being. It's a delicate balance, but understanding these effects helps me manage my digestive health better while reaping the rewards of physical activity.

The Role of Core Muscles in Digestive Health

Core Muscles in Digestive Health

Functions of Stomach and Abdominal Muscles

When I think about my core, it's clear that my stomach and abdominal muscles are more than just show; they're essential for my overall well-being. These muscles stretch from my ribs down to my pelvis, wrapping around my sides and crossing my body diagonally.

They serve as a natural corset, providing support and protection for my internal organs while also facilitating movements like twisting and bending.

The strength of these muscles is crucial for maintaining proper posture and balance. A strong core can prevent back pain and improve my ability to perform everyday activities with ease.

However, when these muscles are weak, it can lead to a host of issues, including reduced movement in the core area and difficulty with actions as simple as sitting up.

Here's a quick rundown of the roles my stomach and abdominal muscles play:

  • Supporting the body's frame.
  • Protecting internal organs.
  • Enabling spine movements.
  • Assisting in breathing.
  • Contributing to balance and stability.

Recognizing the importance of these muscles is the first step towards understanding why my stomach might hurt when I run. It's a reminder that keeping them strong and healthy is not just about aesthetics, but also about functional fitness and digestive health.

The Connection Between Muscle Strength and Digestive Efficiency

I've come to understand that the strength of our core muscles plays a pivotal role in our digestive health. Strong abdominal muscles are essential for supporting the digestive process.

They assist in the movement of food through the digestive tract by facilitating peristalsis, the wave-like contractions that move food along. When these muscles are weak, digestion can become sluggish, leading to discomfort during activities like running.

It's not just about the discomfort, though. Efficient digestion relies on a well-coordinated effort between various bodily functions.

Here's a simple breakdown of how core strength impacts digestion:

  • Supports the stomach and intestines: Helps maintain optimal positioning for digestive organs.
  • Facilitates peristalsis: Aids in the smooth movement of food through the digestive system.
  • Enhances breathing: Strong core muscles contribute to effective diaphragm function, which is crucial for deep breathing during exercise.

By maintaining a strong core, I'm not only improving my posture and balance but also ensuring that my digestive system has the muscular support it needs to function at its best. This is especially important when I'm pushing my body to its limits during a run.

Post-Run Nutrition: Key to Muscle and Stomach Recovery

Replenishing Glycogen and Repairing Muscle Damage

After a run, I'm often focused on catching my breath and cooling down, but I know that's also the prime time to start the recovery process. My muscles are eager for nutrients to repair the micro-tears and replenish the glycogen stores that have been depleted.

Eating the right post-run foods is crucial for muscle recovery and preparing for my next workout.

A balanced post-run meal should include:

  • A good source of carbohydrates to restore glycogen levels.
  • Protein to aid in muscle repair.
  • Fluids and electrolytes to rehydrate and replenish what was lost through sweat.

The recommended amount of carbohydrates is 1.2 grams per kilogram of body weight, which helps to ensure that I'm not going into my next session depleted and at greater risk of injury. Including protein is also beneficial as it encourages the uptake of carbs into the muscles and starts the repair process.

As for hydration, it's not just about the water; electrolytes like sodium, chloride, and potassium are essential for efficient glycogen conversion and drawing more fluid back into the body.

Balancing Electrolytes and Minerals Post-Exercise

After a good run, it's not just about quenching my thirst; it's about restoring the balance my body craves. Electrolytes like sodium, potassium, and calcium are crucial for reestablishing my body's fluid balance and replacing what's lost through sweat.

I've learned that rehydration is only effective when it includes these key minerals, as they not only replenish but also help draw more fluid back into my system.

Here's a simple list of foods and drinks that are great for delivering those much-needed electrolytes:

  • Bananas.
  • Coconut water.
  • Avocados.

It's important to remember that the right post-run nutrition is about more than just refueling; it's a delicate dance of repair and replenishment. By choosing foods rich in electrolytes, I'm not just satisfying my immediate thirst—I'm taking steps to ensure my muscles recover properly and my energy levels are restored for the next challenge.

Ideal Meals to Support Digestive and Muscle Recovery

After a good run, it's crucial to refuel with the right nutrients to aid in recovery and prepare for the next bout of activity. A balanced meal with complex carbs, healthy fats, and protein sets the stage for effective muscle repair and replenishment of energy stores.

Recovery bars or shakes with a 3:1 ratio of carbs to protein can be particularly beneficial for their convenience and balanced nutrition.

Here's a quick list of some post-run meal ideas:

  • Recovery bars or shakes with a 3:1 carb-to-protein ratio
  • Fresh fruit smoothies, blending in a banana for potassium
  • Chocolate milk is a simple option with a good nutrient mix
  • Fresh yogurt with toppings like fruit, honey, or granola
  • Nut butters, which are great on whole-grain toast
  • Protein-rich foods like tuna, salmon, or chicken
  • Salty snacks such as salted nuts to replenish sodium levels

Remember, if you've had an intense session or another workout planned soon, it's important to eat soon after finishing your run. For those who find it hard to eat solid foods right away, a fruit smoothie or chocolate milk can be a soothing alternative. And don't forget, hydration is key, so pair your meal with plenty of water or an electrolyte drink to rehydrate.

Recommended Article: Best Snacks for Gut Health

The Unseen Culprits: Bloating and Gas During Exercise


How Swallowed Air Contributes to Gastrointestinal Discomfort

When I run, I've noticed that sometimes my stomach starts to feel uncomfortable, and it turns out that swallowed air can be a significant contributor to this sensation. Swallowing air while eating or drinking is a common occurrence, but during a run, this can be exacerbated by heavy breathing or even sipping water too quickly.

This trapped air can lead to a feeling of bloating and can cause abdominal pain or discomfort.

It's not just about the air I swallow; it's also about how my body deals with it. Normally, swallowed air is released through belching, but when I'm running, the body's focus on physical exertion can disrupt this natural process. The result is an increase in gas within my stomach, which can lead to that all-too-familiar bloated feeling.

Here are some self-care strategies that I've found helpful in reducing the severity of bloating:

  • Decrease the intake of common trigger foods like full-fat dairy and certain vegetables.
  • Drink plenty of water throughout the day, not just during meals.
  • Engage in regular physical activity to promote healthy digestion.
  • Consider taking specialized supplements if recommended by a healthcare provider.

If the bloating is persistent and painful, it's important to consult a doctor to rule out any underlying conditions. Remember, while it's a common issue among runners, it's not something you have to endure without seeking relief.

Managing Excess Gas and Bloating Post-Run

After a satisfying run, it's not uncommon to experience some bloating. While it's usually temporary, I know how uncomfortable it can be. To manage this, I've learned to focus on my breathing. Steady, low breaths through the nose can help minimize swallowing air, which contributes to bloating.

Here's a quick list of tips that have helped me keep post-run bloating at bay:

  • Avoid eating large meals or gas-producing foods right before running.
  • Stay hydrated, but be mindful not to overdo it as excessive water intake can lead to bloating.
  • Incorporate electrolytes into your post-run routine to help balance fluids in the body.

Remember, the goal is to support your body's recovery without adding digestive stress. By paying attention to these simple habits, I've noticed a significant reduction in post-run bloating and an overall improvement in my comfort and performance.

Recommended Article: Learn Why Does Coffee Make Your Stomach Hurt Guide By Dr. Jeff

Stomach Muscle Weakness and Its Relation to Muscle Diseases


Stomach Muscle Weakness

Identifying Weak Core Muscles and Associated Health Conditions

When I consider the strength of my core muscles, I'm reminded of their importance not just for stability and posture, but also for my overall health. A weak core can manifest in various ways, such as reduced movement, difficulty performing sit-ups, or even persistent back problems.

These symptoms might seem innocuous at first, but they can be indicative of underlying health issues.

It's crucial to recognize that while proximal muscle diseases are rare, they are one of the conditions linked to core muscle weakness. These diseases primarily affect muscles close to the body's core, including the abdominal area. If you're experiencing any of these symptoms, it's essential to consult with a doctor.

To ensure a productive discussion, I make a point to reflect on all my symptoms before the appointment.

Here's a quick checklist of related symptoms that might warrant further investigation:

  • Reduced core movement.
  • Back problems.
  • Difficulty doing a sit-up.
  • Muscle weakness in legs, hips, arms, and shoulders.
  • Neck, throat, or facial muscle weakness.

Remember, these symptoms could stem from a variety of causes, so professional medical advice is key to identifying the root of the problem and determining the appropriate course of action.

Proximal Muscle Diseases and Their Impact on Digestive Health

When we consider the health of our stomach muscles, it's important to recognize that they're part of a complex system that includes the proximal muscles—those closest to the core of our body.

Weakness in these muscles can significantly affect our digestive health, as they play a crucial role in supporting the organs involved in digestion.

A variety of proximal muscle diseases can lead to such weakness, including conditions like Pompe disease, Duchenne and Becker muscular dystrophy, myasthenia gravis, and others. These diseases often manifest symptoms that extend beyond the core, affecting the upper legs, hips, arms, shoulders, and even facial muscles.

Here's a brief overview of how core muscle weakness may present itself in the context of these diseases:

  • Reduced core movement.
  • Difficulty performing movements like sit-ups.
  • Back problems.
  • Potential for digestive discomfort due to compromised support.

It's crucial to remember that these conditions are rare, but if you're experiencing any of these symptoms, it's advisable to consult with a healthcare professional. They can help determine whether your symptoms are related to a proximal muscle disease or another health issue.

Frequently Asked Questions

1. Why does high-intensity exercise cause stomach pain?

High-intensity exercise can lead to stomach pain because our digestive organs struggle to process water and food efficiently during strenuous workouts. This can cause severe nausea and discomfort, sometimes forcing athletes to drop out of races.

2. How does heat and dehydration affect my stomach during exercise?

Heat can worsen digestive problems by causing blood to flow away from internal organs to the skin, which cools you down but also slows digestion. Dehydration thickens your blood, further slowing its movement and exacerbating digestive symptoms.

3. Can heavy breathing during exercise cause digestive issues?

Yes, heavy or rapid breathing during intense workouts can result in swallowing air, which can lead to bloating and gastrointestinal discomfort.

4. What role do stomach muscles play in my overall health?

Stomach muscles support the body's frame, protect internal organs, and enable movements like twisting the spine and sitting up. Weakness in these muscles can be associated with a range of health conditions, including proximal muscle diseases.

5. What should I eat after a run to aid in muscle and stomach recovery?

After a run, it's important to eat foods that replenish glycogen stores, repair muscle damage, and replace lost fluids, electrolytes, and minerals. A balanced meal with complex carbs, healthy fats, and protein is ideal for recovery.

6. Why do I experience bloating and gas during exercise?

Bloating and gas during exercise can be caused by swallowing air, hormonal changes, or the body's response to high-intensity activity, such as the production of metabolic byproducts like lactate that the body tries to eliminate, sometimes through vomiting.


Understanding the various factors that contribute to stomach pain during running is crucial for athletes and fitness enthusiasts alike. From the physiological demands of high-intensity exercise on our digestive system to the impact of dehydration, heat, and dietary choices, it's clear that our bodies require careful attention and training to manage these challenges.

By recognizing the importance of proper hydration, nutrition, and pacing, runners can mitigate discomfort and enhance their performance. It's also essential to listen to our bodies and adjust our routines accordingly, ensuring that we provide the necessary resources for recovery and maintain overall gut health.

Remember, while pushing our limits can lead to growth, it's equally important to nurture our bodies to sustain long-term health and athletic success.

Dr. Jeffrey Mark
With over thirty years of experience, Dr. Mark is a leading expert in holistic gut health. His integrative approach combines conventional medicine, functional and regenerative medicine, and advanced therapies to heal the gut and transform patient health. Holding 5 board certifications, Dr. Mark offers the comprehensive expertise of five medical specialists during each patient visit. He is dedicated to optimizing wellbeing by addressing the gut-related root causes of chronic health issues.
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