American runner Bill Rodgers once quipped, “More marathons are won or lost in the port-a-loo than at the dinner table.” No kidding. Rare is the distance runner who hasn’t had some stomach or bowel distress during a race. And even though marathons aren’t often televised, there have been several famous cases of on-camera elites vomiting or ducking off course en route.
In fact, studies have shown that 30 to 90 per cent of endurance athletes suffer from some form of stomach/bowel distress, with the percent increasing with longer distances.
A new summary in Sports Medicine reviews what’s known about on-the-go gastrointestinal complaints, and what you can do to avoid such problems. We’ll spare you the discussion about abdominal angina, splanchnic perfusion, gut mucosal permeability, gastro-esophageal reflux, and the like, and cut straight to the chase.
Here, paraphrased, are the best ways to avoid problems.
1. Avoid high-fibre foods for several days before your event.
2. Avoid aspirin and NSAIDS like ibuprofen, especially if you have a history of stomach issues while running/racing.
3. Avoid high-fructose foods, particularly sports drinks that are sweetened only with fructose. Somewhat paradoxically, drinks that contain some fructose along with other sweeteners such as glucose appear to be less troublesome.
4. Avoid dehydration. Practice drinking in training to improve your comfort with fluids on board. Don’t overdrink in races simply because there are so many water tables and sports drinks available.
5. Don’t use overly sweetened drinks or mix sports drinks, gels, bars, etc. Yes, more sugar means more kilojoules for energy, but it also means increased risk of stomach distress.
6. If you’ve had problems in the past, practice new nutrition strategies, both pre-event meals and drinking while running. An interesting though still speculative hypothesis indicates that nitrate supplements might ease stomach problems during exercise. This is an intriguing approach because nitrate might also improve performance, at least in non-elite runners.