The purpose of this study is to measure the effects of carbohydrate ingestion during exercise in the heat by measuring markers of gastrointestinal damage and inflammation. Methods: Active subjects (n = 7) completed two 60-min running trials in a heated environment (70% VO2max, 30°C). At minute 20 of exercise, subjects consumed a carbohydrate gel (Cho) (27 g), or a non-carbohydrate placebo (nCho). Plasma endotoxin, I-FABP, TNF-α, IL-6, IL-1β, IL-10, and MCP-1 were measured pre-exercise, 20-min post-exercise, and again 2-h, and 4-h post-exercise. Results: Endotoxin increased 20-min post-exercise compared to pre in the Cho trial only (p =.03). I-FABP levels increased 20-min post-exercise in the Cho trial only compared to pre-exercise (p =.003). I-FABP levels were also increased in Cho trial 20-min post-exercise when compared to same time point in the nCho trial (p =.032). TNF-α increased 20-min post-exercise in the Cho trial only compared to pre (p =.03). Plasma IL-6 concentration increased 20-min post-exercise when compared to pre in both the Cho (p =.002) and nCho (p =.009), but remained elevated at the 2-h time point in the nCho trial (p =.03). I-FABP and several plasma cytokines (TNF-α, MCP-1, Il-6) returned to baseline sooner in the Cho trial. Conclusions: Ingestion of carbohydrate gel during exercise in the heat enhances markers of gastrointestinal wall damage.
- Intestinal integrity
- carbohydrate ingestion