One of the most common questions runners ask is: “How can I prevent or cope with stomach problems during training and races?”
It’s not an issue many of us like to talk about openly, but it’s one that’s surprisingly common among runners.
A common condition
It is estimated that 30 to 50 per cent of endurance athletes experience gut problems related to exercise. The most debilitating and annoying of these seems to be the sudden and overwhelming need to evacuate your bowels. In cases of extreme frequency or discomfort, this is known as runner’s diarrhoea or ‘runner’s trots’.
Other common problems include abdominal pain and cramping, belching, bloating, nausea, heartburn, flatulence and vomiting. In a study at Maastrict University, in the Netherlands, 93 per cent of triathletes had at least one gastrointestinal (GI) symptom, of which 29 per cent were serious enough to affect performance.
All shook up
One reason why stomach problems are particularly common when running is the repeated and sustained up-and-down movements it involves. This means all the food inside your gut is literally shaken and loosened. This is exacerbated by reduced blood flow to your intestines as more of your blood is diverted to your exercising muscles.
Even if you’re fine during training, you may experience stomach discomfort or an urge to ‘go’ shortly before a race. This is a natural response to stress as your body goes into ‘fight-or-flight’ mode. Stress hormones are released and the digestive process slows or even stops temporarily so that your body can divert all its internal energy to facing a perceived threat.
Certain foods may irritate the gut too – for example high intakes of fibre, fat, protein or fructose. Dehydration or consuming a drink that has a concentration of carbohydrate that you’re unaccustomed to can also add to the stress on the gut.
The good news is you can fight back! See our tips on how to avoid stomach problems and pit-stops while running below...