Gut-training: the impact of two weeks repetitive gut-challenge during exercise on gastrointestinal status, glucose availability, fuel kinetics, and running performance.
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% V̇O2maxwhilst 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). H2peak 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.
a Monash University, Department of Nutrition & Dietetics, Level 1, 264 Ferntree Gully road, Notting Hill, 3168 Victoria, Australia.
Ricardo J S
RJS
Costa
a Monash University, Department of Nutrition & Dietetics, Level 1, 264 Ferntree Gully road, Notting Hill, 3168 Victoria, Australia.
Atlanta
A
Miall
a Monash University, Department of Nutrition & Dietetics, Level 1, 264 Ferntree Gully road, Notting Hill, 3168 Victoria, Australia.
Anthony
A
Khoo
a Monash University, Department of Nutrition & Dietetics, Level 1, 264 Ferntree Gully road, Notting Hill, 3168 Victoria, Australia.
Christopher
C
Rauch
a Monash University, Department of Nutrition & Dietetics, Level 1, 264 Ferntree Gully road, Notting Hill, 3168 Victoria, Australia.
Rhiannon
R
Snipe
a Monash University, Department of Nutrition & Dietetics, Level 1, 264 Ferntree Gully road, Notting Hill, 3168 Victoria, Australia.
Vera
V
Camões-Costa
b Monash University, Department of Gastroenterology-The Alfred Hospital, 55 Commercial road, Melbourne, 3004 Victoria, Australia.
Peter
P
Gibson
D000222:Adaptation, Physiological; D001786:Blood Glucose; D004032:Diet; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D015444:Exercise / Q000502:physiology*; D005504:Food Analysis; D041981:Gastrointestinal Tract; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D008297:Male; D010807:Physical Endurance; D012420:Running / Q000502:physiology*
D001786:Blood Glucose; D004040:Dietary Carbohydrates; D005947:Glucose
I-FABP; breath hydrogen; carbohydrates; exercice physique; exercise; gastrointestinal symptoms; sucres; symptômes gastro-intestinaux; taux respiratoire d’hydrogène