Supplementation With A Highly Branched Cyclic Dextrin Solution During Ski Mountaineering: A Randomized Clinical Trial

Ski mountaineering (skimo) is a high-intensity sport requiring athletes to ascend and descend mountainous terrain multiple times, resulting in unique challenges that can make consuming food and fluids difficult. To help hydration of athletes, solutions made with a highly branched cyclic dextrin (HBCD) and fructose were utilized. HBCDs have a low osmolarity and quick gastric emptying timing, potentially beneficial for hydration in high endurance exercise. PURPOSE: To compare how solutions containing 6% and 18% HBCD+ fructose (3:1) influence drink palatability, hydration, GI distress, and performance. METHODS: Participants (n = 15) were experienced skimo racers ≥18 years who had participated in skimo ≥ one year or competed in ≥ two races. A double-blind, randomized, crossover research design was completed to compare 6% (30 g CHO/500 mL/h) and 18% (90 g CHO/500 mL/h) solutions during an 11.3 km race consisting of seven course laps. Palatability (0-10), urine specific gravity, GI distress (0-10), lap time, and race time were measured. Paired t-tests were used to determine the difference between the two conditions. RESULTS: Palatability (mean ± SD, 7.6 ± 1.76 vs. 7.2 ± 2.37, p = 0.424) and change in urine specific gravity (0.0014 ± 0.0059, 0.0004 ± 0.008, p = 0.596) were not different between conditions. GI distress scores trended lower in 6% (0.07 ± 1.44, 2.4 ± 2.75, p = 0.073), and four participants in the 18% condition had GI distress scores >4. Overall race time (105.34 ± 17.01 vs 107.13 ± 17.31 min, p = 0.135) and lap time change compared to the first lap (p = 0.324) did not differ between conditions. When those experiencing GI upset (> 4) were excluded, lap time increases were attenuated in the 18% condition (p = 0.01). CONCLUSIONS: An 18% CHO solution did not confer an overall performance benefit when compared to 6% but may produce a performance benefit when gastrointestinal distress is not experienced. Supported by: Kreighbaum Endowment