Comparative effects of a glucose–fructose bar, glucose–fructose hydrogel and maltodextrin gel on carbohydrate oxidation and sprint performance in Tier 2 athletes

Carbohydrate supplementation optimises athletic performance, but the metabolic and performance impacts of commercial products/compositions are underexplored. We compared the efficacy of three commercial carbohydrate supplements: a glucose-fructose bar (GF-Bar), a glucose-fructose hydrogel (GF-Gel) and a maltodextrin-based gel (MD-Gel). Antegrade venous blood samples for glucose and insulin were measured alongside substrate utilisation in healthy Tier 2 athletes after ingesting 45 g of carbohydrates from the GF-Bar, GF-Gel and MD-Gel during a modified 1-h oral glucose tolerance test (OGTT). Additionally, the effect of supplementation on high-intensity interval exercise was evaluated during repeated maximal sprint performance. During the OGTT, the GF-Bar elicited greater total carbohydrate oxidation than MD-Gel (24.6 ± 7.4 g vs. 17.8 ± 8.6 g, P = 0.038) but not GF-Gel (20.1 ± 6.4 g, P > 0.05). Carbohydrate oxidation per minute varied over time (P < 0.001) and between products (P = 0.043), with GF-Bar (0.27 ± 0.05 g min^-1) showing higher oxidation than GF-Gel (0.21 ± 0.05 g min^-1) and MD-Gel (0.19 ± 0.06 g min^-1). No differences were observed in glucose peak, time to peak glucose or insulin concentration (P > 0.05). Peak power (P = 0.011), mean power (P < 0.001) and total work varied across sprints (P < 0.001) but not between products (P > 0.05). Perceived exertion and gastrointestinal discomfort were similar between products (P > 0.05). Despite differences in carbohydrate oxidation during the OGTT, the GF-Bar, GF-Gel and MD-Gel displayed similar metabolic and sprint performance outcomes, suggesting that, within this study, carbohydrate formulation did not impact short-duration maximal exercise.