Effect of a sports drink based on highly-branched cyclic dextrin on cytokine responses to exhaustive endurance exercise.

Aim of the present study was to compare the effects of highly branched cyclic dextrin (HBCD) drink with a glucose-based control drink on immunoendocrine responses to endurance exercise. Using a randomized, double-blind placebo-controlled cross-over design, seven male triathletes participated in two duathlon races separated by one month, consisting of 5 km of running, 40 km of cycling and 5 km of running. In the first race, four athletes consumed the HBCD-based drink and three athletes consumed the glucose-based drink. In the second race, three athletes consumed the HBCD-based drink and four athletes consumed the glucose-based drink. We collected blood and urine samples before and after the races to analyze leukocyte count and concentrations of hormones and cytokines. Lymphocyte and neutrophil counts increased significantly after exercise in both trials (P<0.05), but were not significantly different between the trials. Plasma noradrenalin concentration increased significantly (P<0.05) during exercise in the glucose trial, but not in the HBCD trial. Plasma concentrations of interleukin (IL)-8 and IL-10 increased significantly during exercise in both trials (P<0.05) but were not significantly different between the trials. Post-race urinary IL-8, IL-10 and IL-12p40 concentrations were significantly lower in the HBCD trial compared with the glucose trial (P<0.05), although the plasma concentrations of these cytokines were not significantly different between both trials. These results suggest that the HBCD-based drink may attenuate the stress hormone response, and reduce the urinary cytokine levels following exhaustive exercise.