Low FODMAP: A Preliminary Strategy to Reduce Gastrointestinal Distress in Athletes

Introduction: Gastrointestinal (GI) distress in endurance athletes is prevalent and detrimental to performance. Adverse GI symptomatology can be analogous with irritable bowel syndrome, where fermentable oligosaccharide, disaccharide, monosaccharide and polyols (FODMAP) reduction has demonstrated efficacy. This study investigated the effects of low FODMAP (LFOD) diet on GI distress parameters in runners with a history of non-clinical exerciseassociated GI symptoms.

Methods: Eleven recreationally competitive runners (5 males, 6 females; 5km personal best 23:00±4:02 min:sec) participated in the study. Runners were allocated to a randomized 6-day LFOD or high FODMAP (HFOD) diet separated by a 1-day wash-out in a controlled, single-blinded cross-over study. In each period participants completed two strenuous running sessions consisting of 5x1000m and a 7km threshold run. GI symptoms (during-exercise and daily) and the Daily Analysis of Life Demand for Athletes (DALDA) questionnaires were completed. Area under the curve (AUC) was calculated for daily GI symptoms across each dietary period and analysis was conducted using multilevel mixed-effects linear regression for comparison between the two diets.

Results: A significantly smaller AUC for daily GI symptoms.6-days-1 during the LFOD compared to HFOD (mean difference -13.4, 95% CI [-22, -4.60], P=0.003) was observed. The daily GI symptoms that were significantly lower during LFOD were flatulence (P<0.001), urge to defecate (P=0.04), loose stool (P=0.03) and diarrhea (P=0.004). No significant differences in during exercise symptoms or DALDA responses were observed between diets (p>0.05).

Conclusion: Preliminary findings suggest that short-term FODMAP reduction may be a beneficial intervention to minimize daily GI symptoms in runners with exercise-related GI distress.