Diet is an important trigger of gastrointestinal (GI) symptoms in athletes and increased symptom severity is associated with underperformance (Lis, 2019). Proper nutrition in athletes is important to support performance and recovery, promote adequate energy intake, ensure good mental health and much more. Suboptimal nutritional intake can occur when athletes lack the tools and management strategies they need to adequately manage GI distress. Excessive dietary restriction can lower total energy, protein and carbohydrate intake and increase risk for nutritional deficiencies (Lis, 2019). Various tools and strategies are available to ensure proper fueling and support athletes needing to manage digestive issues.
Diet as Trigger for Gastrointestinal Distress
Thirty to fifty percent (30-50%) of athletes cite GI issues as one of the most common causes of underperformance in endurance events and many eliminate food groups they believe cause GI distress (de Oliveira). Common food groups eliminated include wheat and gluten, dairy and FODMAPs.
FODMAPs are widely consumed by athletes’ and found in foods such as fruits, vegetables, dairy, wheat, grains, legumes, and are commonly added to sports supplements. Only 15% of athletes’ diets would be considered low FODMAP (Killian, 2021). High FODMAP intake in athletes is partially a result of the high energy needs athletes require to fuel. FODMAPs are prevalent in carbohydrate-containing foods, which are a vital macronutrient in the diet of athletes who need high amounts of energy to support training and competition.
Additionally, high FODMAP supplements are common in athletes’ diets. High FODMAP ingredients are often added to sport foods to improve palatability and nutrient profile. These may include whey and milk-based protein powders, various prebiotic and fiber supplements (chicory root, inulin, fructooligosaccharides (FOS)), “greens” powders, beet-based vasodilators, and some multivitamins. High FODMAP sweeteners are also prevalent, such as honey, agave, high fructose corn syrup, sorbitol and xylitol.
Increasingly, there is more recognition that the FODMAPs in wheat and other common foods in athletes’ diets may contribute to GI symptoms (Lis, 2018). In a small study, a low FODMAP diet (LFD) helped reduce symptoms in 69% of recreational athletes with GI symptoms. Participants noted an improvement in pain, flatulence and bloating (Wiffin, 2019). There is little evidence, however, that a gluten-free diet (GFD) improves performance and when it does, the reduction in fructan intake associated with wheat elimination is hypothesized as the main reason for symptom improvement (Lis, 2015, Wiffin, 2019).
Implementing Low FODMAP in Athletes
Particular care must be taken when implementing a FODMAP-targeted approach, especially among athletes. Athletes’ diets are often influenced by others in their ecosystem, such as coaches, peers and the media, which can contribute to confusion and improper implementation of dietary advice (Killian, 2019). Risk for disordered eating and eating disorders is also high among the athlete population, meaning a restrictive elimination diet must be implemented with extreme care, if at all. Athletes are under considerable stress and are generally driven towards “perfection,” meaning ongoing screening to assess relationship to food is always recommended.
There are additional strategies that can be used when managing FODMAP-related GI symptoms in athletes. For example, nutrient intake can be timed with particular concern to spread FODMAPs throughout the day and avoid excessive consumption of any one FODMAP at a meal or snack. FODMAP intake can also be limited just during the 24-48 hours prior to an event. FODMAP-targeting digestive enzymes can also allow for more FODMAP intake and facilitate social inclusion at team meal times.
Learn More: Fueling Performance
Still, FODMAPs are only part of the picture when it comes to managing GI issues in athletes. In a recent webinar with Lauren Cornell, MS, RD, Fueling Performance: Managing GI Symptoms in Athletes, Lauren shares how to personalize nutrition plans to optimize performance. Strategies include pre-exercise, during exercise, and post-exercise nutrition recommendations, as well as hydration considerations to manage GI issues in athletes. She also provides helpful, actional tips and advice to support athletes, such as low FODMAP ingredients to look for in GI-friendly hydration and recommended fueling supplements.
Successful symptom management in the athlete population requires close coordination and collaboration between all members in an athlete’s coaching and support network. Nutritional counseling of athletes with GI symptoms should include a focus on skills to support autonomy and confidence in dietary choices, which helps ensure athletes are well-positioned to understand and implement the least restrictive diet possible and achieve optimal performance.
References
- Lis DM, Kings D, Larson-Meyer DE. Dietary Practices Adopted by Track-and-Field Athletes: Gluten-Free, Low FODMAP, Vegetarian, and Fasting. Int J Sport Nutr Exerc Metab. 2019;29(2):236-245. doi:10.1123/ijsnem.2018-0309
- de Oliveira EP, Burini RC, Jeukendrup A. Gastrointestinal complaints during exercise: prevalence, etiology, and nutritional recommendations. Sports Med. 2014;44(1):79–85. doi: 10.1007/s40279-014-0153-2.
- Killian LA, Muir JG, Barrett JS, Burd NA, Lee SY. High Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols (FODMAP) Consumption Among Endurance Athletes and Relationship to Gastrointestinal Symptoms. Front Nutr. 2021;8:637160. Published 2021 Apr 20. doi:10.3389/fnut.2021.637160
- Lis DM, Stellingwerff T, Kitic CM, Fell JW, Ahuja KDK. Low FODMAP: A Preliminary Strategy to Reduce Gastrointestinal Distress in Athletes. Med Sci Sports Exerc. 2018;50(1):116-123. doi:10.1249/MSS.0000000000001419
- Lis D, Stellingwerff T, Kitic CM, Ahuja KDK, Fell J. No effects of a short-term gluten-free diet on performance in nonceliac athletes. Med Sci Sport Exerc. 2015;47(12):2563–2570. doi: 10.1249/MSS.0000000000000699.
- Wiffin M, Smith L, Antonio J, Johnstone J, Beasley L, Roberts J. Effect of a short-term low fermentable oligiosaccharide, disaccharide, monosaccharide and polyol (FODMAP) diet on exercise-related gastrointestinal symptoms. J Int Soc Sports Nutr. 2019;16(1):1. Published 2019 Jan 15. doi:10.1186/s12970-019-0268-9
- Killian LA, Lee SY. et al. Irritable Bowel Syndrome Is Underdiagnosed and Ineffectively Managed Among Endurance Athletes. Appl Physiol Nutr Metab. 2019 Dec;44(12):1329-1338.
