The FODMAP Diet Part 1: An Overview

Many athletes, particularly endurance athletes, experience gastrointestinal (GI) distress sometime during their training and, or, competition [1, 2]. These symptoms typically mimic those experiences in IBS patients such as abdominal pain, bloating, excessive gas, diarrhoea etc. In some circumstances these symptoms can impair performance or lead to the athlete withdrawing from competition altogether. The FODMAP diet has been gaining some popularity as a method of reducing GI symptoms in athletes, with some case studies showing promising results [3, 4]. Whilst the subject of FODMAPs is extensive and I’ll be covering specific areas in future posts, this article aims to introduce FODMAPs and how this strategy could be beneficial.

Originating from Monash University in Melbourne, an institution producing some excellent research in the area of the GI system in athletes and one which has provided many references for my doctoral research, “FODMAP” stand for fermentable oligosaccharide, disaccharide, monosaccharide and polyols – the acronym is obviously easier to pronounce! These are shorter chain carbohydrates which aren’t as efficiently absorbed in the GI tract. They are easily fermented by colonic bacteria, increasing pressure within the intestine through gas production, and osmotic load whereby water is drawn back into the intestine which then passes through the GI tract and leads to diarrhoea. FODMAPs themselves do not cause IBS, a highly complex pathology, they simply exacerbate symptoms that you may experience. The diet can be complex and essentially involves the removal of certain foods from the diet, this could have a knock-on effect of creating a diet deficient in certain nutrients, and therefore, it should be undertaken under the guidance of a qualified dietician.

The ingestion of FODMAPs before, during or after training or competition, partnered with the impaired digestive and absorptive capabilities of the gut in response to exercise, put the athlete at increased risk of malabsorption of these foods [4]. This malabsorption may trigger the occurrence of GI symptoms [5].

The diagram below shows some foods high in FODMAPs. As you can see these are mostly foods that are promoted as part of a healthy diet and consumed by athletes in and around training or competition. If you are an athlete who frequently suffers with GI distress, it may be worth creating a food diary which also logs your training and occurrence of symptoms, then check that diary for certain ‘trigger foods’.



1. de Oliveira, E.P. and R.C. Burini, The impact of physical exercise on the gastrointestinal tract. Curr Opin Clin Nutr Metab Care, 2009. 12(5): p. 533-8.

2. Pugh, J.N., et al., Gastrointestinal symptoms in elite athletes: time to recognise the problem? Br J Sports Med, 2017.

3. Lis, D., et al., Case Study: Utilizing a Low FODMAP Diet to Combat Exercise-Induced Gastrointestinal Symptoms. Int J Sport Nutr Exerc Metab, 2016. 26(5): p. 481-487.

4. Gaskell, S.K. and R.J.S. Costa, Applying a Low-FODMAP Dietary Intervention to a Female Ultra-Endurance Runner With Irritable Bowel Syndrome During a Multi-Stage Ultra-Marathon. Int J Sport Nutr Exerc Metab, 2018: p. 1-19.

5. Costa, R.J.S., et al., Gut-training: the impact of two weeks repetitive gut-challenge during exercise on gastrointestinal status, glucose availability, fuel kinetics, and running performance. Appl Physiol Nutr Metab, 2017. 42(5): p. 547-557.

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