Runner’s diarrhea, often called “runner’s trots,” is a common digestive issue among runners. It involves frequent, loose bowel movements during or immediately after physical activity. Understanding its causes can help manage it effectively.
Why It Happens
Gastrointestinal distress during running stems from physiological responses, dietary factors, hydration, and psychological influences. During intense exercise, the body prioritizes blood flow to working muscles, reducing circulation in the digestive system (splanchnic ischemia). This temporary lack of blood can impair gut function, making intestines more sensitive.
The repetitive, jarring motion of running also contributes to digestive upset by mechanically jostling internal organs. This physical agitation can accelerate transit time through the intestines. Exercise can also trigger hormonal changes, like increased stress hormones, which influence gut motility and absorption.
Certain dietary choices can significantly impact digestive comfort during a run. High-fiber foods like beans, bran, fruits, and vegetables can speed up digestion. High-fat foods take longer to digest and may cause discomfort. Artificial sweeteners can have a laxative effect, and caffeine can also promote bowel movements.
Inadequate hydration can worsen gastrointestinal symptoms during exercise. Dehydration reduces blood volume, intensifying blood shunting away from the gut. Conversely, overhydration can lead to stomach sloshing and electrolyte imbalances. Stress or anxiety can also influence gut motility and contribute to diarrhea.
Preventive Measures
Adjusting dietary habits before a run can significantly reduce digestive issues. Avoid large meals for at least two to three hours prior to exercise. Focusing on low-fiber, easily digestible carbohydrates like white rice, toast, or bananas can provide energy without overloading the digestive system.
Limiting specific food groups a day or two before a significant run can also be helpful. This includes high-fiber foods, high-fat foods, artificial sweeteners, and excessive caffeine. For those with sensitivities, dairy products may also contribute to symptoms and could be limited. Experimenting with different foods during training helps identify individual triggers.
Proper hydration is also important for prevention. Runners should ensure they are well-hydrated in the days leading up to and during a run, consuming fluids steadily rather than in large quantities. Avoiding warm liquids before a run might also help, as they can accelerate food transit. It is also advisable to use the restroom before starting a run to empty the bowels.
Training considerations extend beyond physical conditioning to include gut adaptation. Gradually increasing running intensity and duration allows the digestive system to adapt to the physiological stresses of exercise. It is also wise to avoid introducing new foods, gels, or supplements on race day, as these can cause unexpected reactions. Managing pre-run anxiety through relaxation techniques can additionally minimize stress-induced gut responses.
Managing Symptoms During a Run
When diarrhea strikes mid-run, immediate actions can help manage the discomfort and disruption. Slowing down the pace or taking a walking break can reduce the stress on the digestive system. Prioritizing personal comfort and hygiene involves locating the nearest restroom or a discreet spot if needed. Trying to hold it in can lead to increased cramping and discomfort.
After an acute episode, rehydrating with water and electrolytes is important to prevent dehydration. Diarrhea, especially if sudden and severe, can lead to significant fluid loss. While energy gels and snacks might be tempting, it is generally best to avoid consuming additional ones until symptoms subside to prevent further digestive upset.
Listening to the body is important, and runners should be prepared to cut a run short if symptoms are severe or persistent. Pushing through intense gastrointestinal distress can lead to further dehydration or discomfort. The aim is to mitigate the immediate impact and ensure recovery before resuming activity.
When to Consult a Doctor
While “runner’s diarrhea” is often temporary and resolves with lifestyle adjustments, certain signs indicate a need for professional medical evaluation. If diarrhea persists for more than 24 to 48 hours, or if it becomes chronic and significantly impacts daily life, consulting a healthcare provider is recommended. Persistent symptoms could signal an underlying issue that requires diagnosis and treatment.
Accompanying symptoms that warrant medical attention include blood in the stool, severe abdominal pain, fever, or unexplained weight loss. Signs of severe dehydration, such as extreme thirst, dizziness, or confusion, also necessitate immediate medical care. These symptoms may indicate more serious conditions.
If digestive issues consistently prevent training or cause significant distress despite implementing preventive measures, seeking medical advice is prudent. Exercise-induced gastrointestinal problems can sometimes be symptoms of underlying medical conditions. A medical professional can help identify any underlying causes and develop an appropriate management plan.