That’s right… I said it. I mentioned the unmentionables. As a dietitian specializing in digestive health issues and sports nutrition, this is merely a common topic that falls under both of my areas of specialty.
What is it? Those of you who experience it, know it well. It’s when runners have diarrhea during or immediately after a run, or feel an urgency to have a bowel movement during exercise. The cause for it is still questionable, but there are a few existing scientific theories. One is that there is ischemia, or limited blood flow and required oxygen, to the arteries that supply the small and large intestines. Symptoms of this include abdominal pain and diarrhea. The other most common theory is mechanical trauma, which is simply the fact that running creates more movement of the GI tract – potentially speeding up the transit time of bowel movements and leading to urgency and diarrhea.
What can you do to help prevent runner’s trots if you do sometimes experience it? When it comes to nutrition, you can make sure the fuel you’re ingesting before and during a run do not trigger this embarrassing outcome.
- Ensure you are eating foods that are lower in sugar and have a neutral osmolality.
- Osmolality is the concentration of solutes per kilogram of solvent. Sports drinks and fluids should have a similar osmolality to that of the blood in order to prevent water from the body from flushing into the intestines – which could then cause diarrhea. The solutes we find in beverages typically come from sugar. So, ensure your sports drinks are not too high in sugar. You can make your own sports drink by mixing ½ L of 100% fruit juice with ½ L of water, and 1/3 tsp of salt.
- Stay hydrated.
- Dehydration can decrease blood flow to the small and large intestines. This in turn can cause diarrhea.
- Avoid drinking caffeine before exercise.
- Caffeine can have a laxative effect and speed up transit time, making you need to use the washroom even if it’s inconvenient.
- Avoid eating any foods you might be intolerant to.
- For example, if lactose sometimes gives you problems – avoid it before a run. Any other foods that you may have noticed to cause stomach discomfort or an urgency to go are definitely on the avoid list before exercise.
Get out there and run, problem-free!