Plain language summary
A diet high in fermentable oligosaccharides, disaccharides, monosaccharaides and polyols (FODMAPs) may result in altered gut motility. Research has shown that 30-50% of endurance athletes list gastrointestinal (GI) issues as a cause of underperformance, however there is little evidence on the impact of FODMAPs during endurance training. The aim of this randomised, crossover trial was to determine the effects of a short-term, low FODMAP diet on GI symptoms and perceived ability to exercise in 16 healthy volunteers. Participants were randomly assigned to either a low FODMAP diet or high FODMAP diet for seven days with a seven-day washout period. GI symptoms, perceived ability to exercise and markers of acute GI inflammation were recorded at the beginning and end of each intervention period. This study found a short-term, low FODMAP diet reduced exercise-related GI symptoms and improved perceived ability to exercise compared with a high FODMAP diet. Based on these results, the authors recommend the therapeutic benefits of a sustained low FODMAP diet in athletes be further explored.
Abstract
BACKGROUND Research has demonstrated that low fermentable oligiosaccharide, disaccharide, monosaccharide and polyol (FODMAP) diets improve gastrointestinal (GI) symptoms in irritable bowel syndrome sufferers. Exercise-related GI issues are a common cause of underperformance, with current evidence focusing on the use of FODMAP approaches with recreationally competitive or highly trained athletes. However, there is a paucity of research exploring the potential benefit of FODMAP strategies to support healthy, recreational athletes who experience GI issues during training. This study therefore aimed to assess whether a short-term LOWFODMAP diet improved exercise-related GI symptoms and the perceived ability to exercise in recreational runners. METHODS Sixteen healthy volunteers were randomly assigned in a crossover design manner to either a LOWFODMAP (16.06 ± 1.79 g·d- 1) or HIGHFODMAP (38.65 ± 6.66 g·d- 1) diet for 7 days, with a one week washout period followed by a further 7 days on the alternate diet. Participants rated their gastrointestinal symptoms on an adapted version of the Irritable Bowel Syndrome-Severity Scoring System (IBS-SSS) questionnaire before and at the end of each dietary period. Perceived ability to exercise (frequency, intensity and duration) in relation to each dietary period was also rated using a visual analogue scale. Resting blood samples were collected prior to and on completion of each diet to determine plasma intestinal fatty acid binding protein (I-FABP) as a marker of acute GI injury. RESULTS Overall IBS-SSS score significantly reduced in the LOWFODMAP condition from 81.1 ± 16.4 to 31.3 ± 9.2 (arbitrary units; P = 0.004). Perceived exercise frequency (z = 2.309, P = 0.02) and intensity (z = 2.687, P = 0.007) was significantly improved following a short-term LOWFODMAP approach compared to HIGHFODMAP. No significant differences were reported between dietary conditions for plasma I-FABP (P > 0.05). CONCLUSIONS A short-term LOWFODMAP diet under free-living conditions reduced exercise-related GI symptoms and improved the perceived ability to exercise in otherwise healthy, recreational runners. These findings may be explained by a reduction in indigestible carbohydrates available for fermentation in the gut. The therapeutic benefits of LOWFODMAP diets in recreational and trained athletes during sustained training periods warrants further investigation.
Methodological quality
Jadad score
:
3
Allocation concealment
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Yes
