Gut-training: the impact of two weeks repetitive gut-challenge during exercise on gastrointestinal status, glucose availability, fuel kinetics, and running performance

Ricardo J.S. Costa, Atlanta Miall, Anthony Khoo, Christopher Rauch, Rhiannon Snipe, Vera Camões-Costa, Peter Gibson

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105 Citations (Scopus)


Due to gastrointestinal tract adaptability, the study aimed to determine the impact of gut-training protocol over 2 weeks on gastrointestinal status, blood glucose availability, fuel kinetics, and running performance. Endurance runners (n = 25) performed a gut-challenge trial (GC1), consisting of 2 h running exercise at 60% V̇O2max whilst consuming gel-discs containing 30 g carbohydrates (2:1 glucose/fructose, 10% w/v) every 20 min and a 1 h distance test. Participants were then randomly assigned to a carbohydrate gel-disc (CHO-S), carbohydrate food (CHO-F), or placebo (PLA) gut-training group for 2 weeks of repetitive gut-challenge intervention. Participants then repeated a second gut-challenge trial (GC2). Gastrointestinal symptoms reduced in GC2 on CHO-S (60%; p = 0.008) and CHO-F (63%; p = 0.046); reductions were greater than PLA (p < 0.05). H2 peak was lower in GC2 on CHO-S (mean (CI): 6 (4-8) ppm) compared with CHO-F (9 (6-12) ppm) and PLA (12 (2-21) ppm) (trial × time: p < 0.001). Blood glucose concentration was higher in GC2 on CHO-S (7.2 (6.3-8.1) mmol·L-1) compared with CHO-F (6.1 (5.7-6.5) mmol·L-1) and PLA (6.2 (4.9-7.5) mmol·L-1) (trial × time: p = 0.015). No difference in oxidation rates, plasma I-FABP, and cortisol concentrations were observed between groups and trials. Distance test improved on CHO-S (5.2%) and CHO-F (4.3%) in GC2, but not on PLA (-2.1%) (trial × time: p = 0.009). Two weeks of gut-training with CHO-S and CHO-F improved gastrointestinal symptoms and running performance compared with PLA. CHO-S also reduced malabsorption and increased blood glucose availability during endurance running compared with PLA.

Original languageEnglish
Pages (from-to)547-557
Number of pages11
JournalApplied Physiology, Nutrition and Metabolism
Issue number5
Publication statusPublished - May 2017


  • breath hydrogen
  • carbohydrates
  • exercice physique
  • exercise
  • gastrointestinal symptoms
  • I-FABP
  • sucres
  • symptômes gastro-intestinaux
  • taux respiratoire d’hydrogène

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