Updated: September 29th, 2021
Why running makes you (more often than not) literally run for the toilet.

The colon-call-card for a sudden desperation sprint to the bathroom when exercising has been coined the ‘runners trots’.

  1. Because we are all so familiar with the notion; whether you’re a newbie to the sport or a seasoned athlete; you have no doubt grown accustomed to an emergency detour.
  2. Because obviously running is the best – everything should be named after running.

Nothing will destroy your race time more than a prodding stomach pain urging you to find the loo and QUICK – let alone the laborious waiting in those seemingly endless queues for the porta-potty.

So instead of pooping your pants with excitement for the race, how about, we learn what is going on to cause this colon-calling-card. How to deal and finish your race strong, and more importantly, how to prevent it from destroying your timings for the next race. Oh, the joys of runners trots eh?

What causes runners trots?


“It happens to different people for different reasons, but most common sense is that it’s because you’re moving and that up and down motion seems to stimulate the colon a bit,” Lisa Ganjhu (Gastroenterologist NYU Langone Medical Center). When you start to move, there is an adrenaline surge — your heart rate increases, breathing increases and so does your colon. Stimulating the feeling of needing to go 0.3 seconds ago. Thanks to the adrenaline eruption, the stool moves ever-so-quickly through the bowel – there’s less time for water to be reabsorbed, resulting in a watery rather explosive case on your hands. Probably more familiar with pre-race nerves; butterflies in the stomach feeling, and a nervous poop before the start line. Thank you adrenaline. (I think?)

race day porta potty


Okay, it’s no secret running has a strong oscillatory component. Each stride has you land on one foot only to be sprung off into the air for the next landing – a fair amount of jiggling for the insides. Which would no doubt irritate (I mean wouldn’t you be irritated if someone kept juggling you around?) and makes the bowel uber keen to expel its contents if you will.

Running also prompts your body to shunt blood away from the bowels/GI tract (Gastrointestinal) and towards the muscles working hardest, it is more important for the body that the blood and oxygen go to the muscles. Although good for running, the blood shunting can cause GI distress and stomach cramps not ideal.

In a study of ultra marathoners, 96% experienced gastrointestinal symptoms while running. Meaning, it happens to everyone, whether you’re training for your first race, lacing up for treadmill speedwork, or hitting the pavement outdoors.

stomache cramp


One of the biggest runners problems, especially as many races start early morning. What did you have for breakfast pre-run OR early gels as fuel perhaps?

The longer races(marathons and ultra-marathons) look to start at the crack of dawn – even before the sun rises in some cases! so your choice of breakfast can make or break your race. It is well-known that food causing GI distress are high-fibre or coniferous:

  • Wheat
  • Corn
  • Potatoes
  • Broccoli
  • Cabbage
  • Cauliflower
  • Lentils
  • Artificial sweeteners
  • Caffeine

And should be avoided to prevent food from running through your system as quickly (about the only time you want things to run slow huh?). A fibre-rich diet is great for healthy digestion for day-to-day but conversely, can cause cramping or diarrhoea on race day.

Surprised to see caffeine on the no-no list? Although it can lead to improved performance, the compounds found in caffeine can impact your gut, by actually speeding up how fast it works. Give yourself at least 60 minutes after a coffee to head out on a run, for the longer distances that is. Many energy gels, chews and drinks contain caffeine so make sure your experiment before race day. See what works best for you and which taste the best because some are questionable. (To whoever invented grape flavour… have you tasted grapes before?!)

healthy running breakast

What you can do to prevent runners trots

  • According to the American College of Sports Medicine, It takes the average runner 1,000-plus strides to cover one mile. That’s a lot of pounding for the insides to take. So to help decrease the oscillatory impact of your internals (the bouncing up and down with each stride). Some great advice I received was “On your next run, imagine that a ceiling is one inch above your head; try not to hit it” (I’m 5 foot, I’ve never hit my head on the roof!) you may look like a Goof at the start, but I’m sure it will be worth it.
  • Of course, there’s always tech options, the Garmin Forerunner 630, track vertical oscillation and assist you to become more economical.
  • Get to the bathroom before a run. Especially if you have an early morning start time, get up a little earlier, eat a little earlier so you have time to hit the loo a little earlier before the starting pistol.
  • toilet sign

  • Pre-plan a detour/pitstop. Check the route before heading out. If there is no bathroom facilities available on course (like most trail races) then bring a little toilet paper just in case.
  • Keep the warmup short – and do a few. A small light jog may get the gut moving quickly so you can hit the loo before the start.
  • Slow it down – feeling the stomach cramp coming on? Slow the pace mid-run or even take a rest day if you’re struggling stomach wise.
  • Trial, error and STAY THE HECK AWAY — everyone has different reactions to different foods, so find what does and doesn’t work for you. Use your training to test foods, caffeine, training kit so you are comfortable on race day (in more ways than one). If you find dairy doesn’t agree with you on runs – do yourself a favour and STAY AWAY from dairy on race day and the build-up to it.
  • Record bathroom habits – okay we don’t need the details, but understanding when and how often you tend to use the bathroom before, during and after a run can help you plan your food and training routes.
  • Stay relaxed – This goes for rest days and on race day. Adding to stress won’t help your gut or stomach upset. Use breath-work, calming music, imagery or self-soothe with kind positive supportive words “I know I can do this!”
  • Man breathing

  • Keep hydrated – if you do suffer, have or are prone to suffering from diarrhoea then please make your fluid intake a high priority. Diarrhoea causes a significant loss of body fluid that needs to be replaced, especially if you’re active.
  • Keep it simple – with trial and error, and all the fancy foody things out there you can buy, nothing beats going back to basics – bananas, homemade sports drinks, homemade energy bars/flapjacks, bagels. Sometimes the secret is in the simple!
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