GI symptoms, exercise and ultra running

It’s the last day in our series of articles that offer a taster of the types of articles and information that some Ultra168 patreons can get access to via the Ultra168 insiders tier of support. If you haven’t seen, Ultra168 has started using Patreon as a way of helping to fund the website and there are a whole host of options and ways in which you can show you support. Today we welcome Steph Gaskell, to the pages of ultra168 as she briefly explains GI —issues in runners, but also offers some great help around foods and recipes that could help those who suffer with GI symptoms.

Gastrointestinal (GI) symptoms can occur prior, during or post – training or competition and can negatively influence exercise performance and recovery. Athletes who participate in sport may experience GI symptoms with an estimated prevalence of 30–70%.

It is particularly common in endurance athletes with more than 60% of ultra endurance athletes reporting severe symptoms, in hot or temperate ambient conditions (Costa et al 2017). Shorter endurance events such as half marathons and marathons, symptoms becomes less prevalent; this signifies that duration is a determinant influencing prevalence of symptoms.

GI complaints during exercise are normally not harmful to health and are typically mild in nature, but serious implications are possible and can result in an inability to maintain work-output and/or withdrawal from activity. The underlying causes for exertional stress induced gut symptoms appears to be multi factorial in origin, but ultimately leads to gut surface damage and leakage, and an overall reduction in food and fluid intake during activity.

Fermentable oligosaccharide disaccharide and polyols (FODMAPs) are short chain carbohydrates that are slowly or poorly absorbed in the small intestine and rapidly fermented in the large bowel (resulting in gas production and movement of fluid into the gut). Read here to understand more about FODMAPs.

Researchers at Monash University have demonstrated that FODMAPs can have major impacts on gut function. There is preliminary research suggesting that reducing the dietary intake of FODMAPs leading into exercise in individuals susceptible to GI symptoms may help reduce the risk of symptoms (Gaskell and Costa In Press, Lis et al 2016, 2017).

Further research on how FODMAPs may impact on exertion induced gut disturbance and its influence on exercise performance is needed. The research project currently being carried out at Monash University  aims to assess the impact of the FODMAP content of the diet prior to prolonged strenuous exercise on markers of intestinal integrity, function, and perceptive gastrointestinal symptoms. 

For further information, check out this blog developed by Monash Sports and Dietetic Team to help manage gastrointestinal symptoms during exercise that includes some during fueling options: – There are also some free recipes on the site too.

  • Costa, R.J.S., Snipe, R., Kitic, C., & Gibson, P. (2017b). Systematic review: Exercise-induced gastrointestinal syndrome- Implication for health and disease. Alimentary Therapeutics & Pharmacology, 46 (3), 246-265.
  • Gaskell S.K., and Costa R.J.S. In Press
  • Lis, D.M., Ahuja, K.D.K., Stellingwerff, T., Kitic, C.M., & Fell, J. (2016). Case Study: Utilizing a low FODMAP diet to combat exercise-induced gastrointestinal symptoms. International Journal of Sport Nutrition and Exercise Metabolism, 26, 481-487.
  • Lis, D.M., Stellingwerff, T., Kitic, C.M., Fell J.W., & Ahuja, K.D.K. (2017). Low FODMAP: A preliminary strategy to reduce gastrointestinal distress in athletes. Medicine & Science in Sports & Exercise. In press.
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I'm a mediocre runner who can bat above his average when I train hard. A man of extremes, I do enjoy everything life offers and consider it an absolute pleasure just to be able to put one foot in front of the other and let my mind wander somewhere different.

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