A low FODMAP diet is one that is low in fermentable oligosaccharide, disaccharide, monosaccharide, and polyol, all of which are short-chain carbohydrates that cumulatively may be poorly absorbed by the body and affect gut motility.
Researchers from the Cambridge Centre for Sport and Exercise Sciences at Anglia Ruskin University in the UK assessed 16 recreational runners who went on a low FODMAP diet and then a high FODMAP diet for one week each.
They found that participants were more likely to report that the ability to exercise improved on a low FODMAP diet versus when on a high FODMAP diet.
“This study provides evidence that recreational athletes implementing a short-term low FODMAP diet under free-living conditions may experience benefits in exercise-related gastrointestinal symptoms and perceived improvements in exercise intensity and frequency,” they wrote in the study, published this week in the Journal of the International Society of Sports Nutrition.
Stomach complaints are a top issue among 30 to 50% of athletes, they said, citing a 2014 study in Sports Medicine conducted by a team of researchers from Brazil, the UK, and the US.
“An interesting observation from the current study was the improved perception of exercise frequency and intensity from participants whilst undertaking the low FODMAP approach,” the researchers from Anglia Ruskin University wrote in their paper.
“Although this only reflected perceived changes in the short-term (7 days), this may have implications for sustained approaches where training routines may be disrupted (including volume and intensity) due to GI-related issues.”
They posited that a reduction of indigestible carbohydrates may have improved the perceived ability to exercise in these otherwise healthy, recreational runners.
Limited data on FODMAP and exercise
Research on FODMAP diets in a healthy population are still emerging.
There is much more literature on its effects on patients with IBS. Though a review from 2015 in Drug and Therapeutics Bulletin argued that there was still very limited evidence on the benefits of eschewing FODMAPs for gastrointestinal health, there are many other studies that prove otherwise.
Meanwhile, food, beverage, and supplement companies continue to invest and develop products in this space.
From a sports nutrition perspective, there is even less literature, authors of this current study argued.
Considering FODMAPs are found in a wide array of food, such as fruits, vegetables, dairy, wheat, grains, legumes, and processed foods, there is a concern that following low FODMAP diets may inadvertently cause a caloric deficit, especially among athletes.
The researchers addressed this concern in their paper, writing that, although improvements were documented, “caution is warranted to minimize unnecessary reductions in total caloric and/or carbohydrate intake that may impact on nutritional quality.”
Sixteen healthy and recreationally active adults participated in this study in a crossover design manner. This means they were randomized to start with either a low FODMAP or high FODMAP diet first.
All participants ate according to their assigned diet for seven days, took a one-week ‘wash-out’ period, and then changed diets to whichever diet they were not assigned for the first period of the study.
Throughout the intervention period, participants were requested to continue their usual exercise routines.
They visited a laboratory prior to and immediately after each dietary period for four visits in total. During these visits, researchers drew blood samples and asked participants to fill out questionnaires to self-assess gastrointestinal symptoms and exercise performance.
Source: Journal of the International Society of Sports Nutrition
Published online, https://doi.org/10.1186/s12970-019-0268-9
“Effect of a short-term low fermentable oligiosaccharide, disaccharide, monosaccharide and polyol (FODMAP) diet on exercise-related gastrointestinal symptoms”
Authors: Melanie Wiffin, et al.