Training Ground

Gut Health and Athletic Performance

Gut Health and Athletic Performance

The Gut: A Non-athletic Organ

The ability of an athlete to achieve peak performance is directly influenced by a combination of overall muscular performance, balanced immune functioning, and biological stress tolerance and adaptation1. In competition, the gut is an essential organ for facilitating both nutrient and water uptake2, and has thus become recognized as a critical pivot point for determining overall health and performance by playing a substantial role in athletic adaptation and regeneration1. Unfortunately, the gut itself is not considered an athletic organ, and under the intensive mechanical and biochemical stress experienced by athletes, the gut lining becomes unable to adapt and rebuild at a rapid enough pace, thus resulting in damage3.

Why Athletes May Have Poor Gut Health

Gastrointestinal distress is a common complaint during training, with research showing this damage to occur in up to 50% of endurance athletes1, 3. These athletes commonly demonstrate symptoms of reduced gut integrity such as cramping, pain, bloating and diarrhea1, with an outcome of overall reduced performance and frequent illness2. Additionally, due to the prevalence of maldigestion, malabsorption and decreased gastrointestinal blood flow, insufficient nutrient and water availability can often persist in spite of seemingly adequate intake3.

With these considerations in mind, appropriate maintenance of gut health is undoubtedly an essential strategy for maximizing athletic performance and recovery, while protecting against frequent illness and gastrointestinal distress1-3.

How to Maximize Gut Health and Performance

One of the best-demonstrated strategies for attenuating the deleterious effects of exercise-induced damage is through supplementation of glutamine, a free amino acid abundant in human plasma and muscle. Glutamine is essential for appropriate repair and immune functioning and, under catabolic conditions such as endurance training and high intensity exercise, has shown to drop below normal biological levels. Furthermore, the direct impact of intensive exercise on decreased glutamine levels may be cumulative, and has been suggested as a potential cause of the compromised immune functioning and increased susceptibility to illness experienced by athletes4

In several studies, glutamine supplementation has demonstrated to enhance gut health, significantly improving integrity of the intestinal lining while decreasing gastrointestinal distress5,6 in as little as 10 days6. Glutamine has also shown the capacity to enhance recovery by curtailing the immunosuppressive effects of intensive training7, reducing the rise in recovery phase fatigue factors8 and restoring overall immune functioning7.

In addition to improving biological markers of health, glutamine has also shown to directly strengthen sports performance, with supplementation demonstrating to enhance upper and lower body reaction time9, prevent reductions in maximal aerobic power10, and produce vastly superior improvements in both exercise performance and tolerance11 compared to other common methods of athletic rehydration alone.

With the apparent importance of gut health in athletics, the incorporation of glutamine into a routine supplement schedule can provide a simple and effective strategy for maintaining overall health and enhancing sports performance. And after all, a healthy body makes for a high-performance athlete!

Happy training,

Anita Tee


  1. Berg A, Muller H, Rathmann S, Deibert P. The gastrointestinal system--an essential target organ of the athlete's health and physical performance. Exercise Immunology Review. 1999;5:78-95.
  2. Murray R. Training the gut for competition. Current Sports Medicine Reports. 2006;5(3):161-164.
  3. Brouns FBeckers E. Is the gut an athletic organ? Digestion, absorption and exercise. Sports Medicine. 1993;15(4):242-257.
  4. Walsh N, Blannin A, Robson P, Gleeson M. Glutamine, exercise and immune function. Links and possible mechanisms. Sports Medicine. 1998;26(3):177-191.
  5. Benjamin J, Makharia G, Ahuja V, Anand Rajan K, Kalaivani M, Gupta S et al. Glutamine and Whey Protein Improve Intestinal Permeability and Morphology in Patients with Crohn’s Disease: A Randomized Controlled Trial. Dig Dis Sci. 2011;57(4):1000-1012.
  6. Lima A, Anstead G, Zhang Q, Figueiredo I, Soares A, Mota R et al. Effects of glutamine alone or in combination with zinc and vitamin A on growth, intestinal barrier function, stress and satiety-related hormones in Brazilian shantytown children. Clinics. 2014;69(4):225-233.
  7. Song Q, Xu R, Zhang Q, Shen G, Ma M, Zhao X et al. Glutamine supplementation and immune function during heavy load training. Int Journal of Clinical Pharmacology and Therapeutics. 2015;53(05):372-376.
  8. Koo G, Woo J, Kang S, Shin K. Effects of Supplementation with BCAA and L-glutamine on Blood Fatigue Factors and Cytokines in Juvenile Athletes Submitted to Maximal Intensity Rowing Performance. J Phys Ther Sci. 2014;26(8):1241-1246.
  9. Pruna G, Hoffman J, McCormack W, Jajtner A, Townsend J, Bohner J et al. Effect of acute L-Alanyl-L-Glutamine and electrolyte ingestion on cognitive function and reaction time following endurance exercise. European Journal of Sport Science. 2014;16(1):72-79.
  10. Khorshidi-Hosseini MNakhostin-Roohi B. Effect of glutamine and maltodextrin acute supplementation on anaerobic power. Asian Journal of Sports Medicine. 2013;4(2):131-136.
  11. Favano A, Santos-Silva P, Nakano E, Pedrinelli A, Hernandez A, Greve J. Peptide glutamine supplementation for tolerance of intermittent exercise in soccer players. Clinics (Sao Paolo). 2008;63(1):27-32.
Anita Tee
Anita Tee - Author

Anita Tee is a nutritional scientist, carrying a Master of Science in Personalized Nutrition and a Bachelor of Science in Genetic & Molecular Biology. Anita is also a personal training specialist, with her main focus on high intensity interval training. To learn more about Anita, follow her on Twitter (@factvsfitness) or check out her website at .

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