Troubleshooting Runners "Bloat"

Bloating is a common complaint among endurance athletes.  It can significantly impact your race after months of training.  Many different factors may contribute to bloating, some serious medical conditions and some not.  In this post I will discuss some of the most common and less serious causes of bloating in endurance athletes.

The GI tract is not as adaptable to exercise as the heart and lungs, each person's issues must be addressed individually. Small changes in your nutrition and racing/training practice could make all the difference.

Of course, if it doesn't, it's time to visit your local Gastroenterologist.

(yes, this is an incredibly embarrassing selfie of me running)

Delayed Gastric Emptying- nausea, feeling of fullness, pain and sometimes vomiting.

 A higher gastric emptying rate during racing is important because the small intestine absorbs the water/nutrients and helps prevent heat stroke and fatigue.  The rate a stomach empties varies from individual to individual, but studies show that in athletes the following affect this rate:

• The higher the carbohydrate percentage, the slower gastric emptying (at least up until a high intensity VO2max, where water and high carbs level out and both empty slowly).  Most recommend no higher than 8% carbohydrates in supplements

• Intensity of exercise

• Volume in the stomach.  A higher volume in your stomach also helps gastric emptying rate. The higher volume that can be tolerated by athletes without GI discomfort is recommended. Adding salt or cold fluids helps athletes get the fluid down.  Salt use to aid in fluid absorption is controversial but the Academy of Sports Medicine does still recommend supplementation to help with pallor of fluids and also to possibly help prevent hyponatremia.

Air Swallowing- common causes are chewing gum, anxiety and positioning.  Laying down or bending forward such as in aeroposition for triathletes could contribute to air swallowing.

Carbohydrate Malabsorption- if your body doesn't absorb the carbs you take in, they stay in the gut allowing for rapid fermentation = MORE GAS. Most people know lactose is a common problem, but fructose malabsorption is a big one too.

Constipation -  This goes along with delayed gastric emptying.  If you're constipated at a baseline, you may find what you take in has no where to go.  Regular BMs even when not exercising are essential for so many reasons.  This is also one of the most common causes for runners diarrhea "runners trots" which I'll blog about another time.

Gluten Sensitivity In this day and age, you can't talk about bloating without talking about gluten sensitivity. This will be addressed in a future blog post, but briefly you may consider switching to gluten free supplements to see if your bloating improves.

If you're still experiencing bloating, see a gastroenterologist to assess other significant health problems which can cause bloating such as chrons disease and celiac disease among others.