The South West Coastal Path. Pennine Way. Hadrian’s Wall. All glorious walking trails, all boasting long stretches without proper toilets. For some, a trip to the loo can wait, or a wild wee behind a bush is an acceptable alternative. But for other...calls of nature, things may prove a bit more problematic. Especially if you happen to notice there’s a certain abdominal rumbling whenever you head out for a long walk.
Some individuals notice that their guts appear to become more active on exertion. This is rather contrary to the normal workings of the body which tend to switch off digestion during exercise – turning instead to our energy stores and focussing on important tasks like driving up our breathing and heart rates. But movement, stress hormones, and certain foods can affect the activity of our guts, causing crampy abdominal pain, an overwhelming urge to open our bowels, and diarrhoea – sometimes explosively, and with little warning.
These symptoms go by several names – runner’s stomach, runner’s gut, runner’s trots, and more. It’s very common in long-distance athletes, but can also affect less active individuals too. There’s no clear explanation as to why, but it’s possible that the bowels being jostled around in the abdomen during exercise may aggravate them, or that they might be misinterpreting signals coming from the brain. Changes in the blood supply, even bacterial growth of the gut have also been implicated – and other causes of diarrhoea, including irritable bowel syndrome, can also be worsened by exercise.
Understanding how your own gut works can help reduce the risk of mishaps or discomfort whilst running or hiking – here are a few tips:
Watch what you eat
It’s always important to ensure that you’ve got adequate calories on board for any form of physical activity. This will not only give you the energy to make it to the finish line, but also prevent fatigue and burnout on the way. Breakfasting well is therefore critical.
However, some foods might push you in the wrong direction – and all nutrient groups have the potential to irritate the gut. Fibre is particularly culpable, as it readily ferments and produces gas. Some fats share the same problem, as do proteins – something we’re often told to eat in abundance when exercising. Unfortunately, some carbs can also result in fermentation – particularly lactose found in dairy products and fruits high in the sugar fructose, like grapes and apples.
“What does this leave me to eat then?” you may well be asking. A suitable breakfast could look like some easily digestible starchy carbs – something like white toast, bagels, or rice and corn-based cereals – nothing too high in associated fibre, like bran or wholemeal breads. It’s also a good idea to go with foods that are more familiar to you and haven’t caused issues in the past.
Try and stick to similar foods when snacking too – you can load up on proteins, fats and fibre later when back at the lodge.
Keep hydrated
It sounds like old advice, but hydration with plain fluids like water, or electrolyte-replenishment drinks can help alleviate the symptoms. This becomes particularly relevant in summer weather: losing water and minerals like sodium in sweat or diarrhoea can also lead to dehydration, cramps, headaches and nausea – making the problem much worse.
So, fill up a large water bottle, strap it to your rucksack and keep it close at hand. Small, frequent sips keep you ticking over, preventing bloating and equally frequent loo trips. Some electrolyte sachets can be a good addition for hot weather, heavy sweating or diarrhoea. Caffeinated or high-sugar drinks might give you an energy boost, but could worsen gut symptoms with their laxative effects – use with care.
On the trail
For some however, gut symptoms on hikes or runs, particularly where company is involved, can be an embarrassing, even mortifying experience.
Listen to your body and what it’s telling you. Going in too fast, too soon and without adequate preparation for an event might be the underlying cause, so some training and warming up can help beforehand. It can also give you some time to identify symptoms in advance. Keep a diary of what you’ve eaten and the symptoms you’ve experienced if you’re noticing any recurrent symptoms – it can really help map out the problem, and find a solution.
Some people have learned to embrace the farts, even communally – and it’s true that taking a stroll after a meal can really help release the feeling of bloating that comes with a full stomach. If you are becoming self-conscious about them and don’t want to share, you don’t have to let on – ask to take a break, slow down and rehydrate. It might keep things at bay until you can get to a toilet.
Dr Daniel Baumgardt is a Gloucestershire-based rural GP and senior lecturer in pharmacology and toxicology at the University of Bristol.
