Background: 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.
Methods: 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.
Results: 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.
Conclusion: These results suggest that the HBCD-based drink may attenuate the stress hormone response, and reduce the urinary cytokine levels following exhaustive exercise.