CARBOHYDRATE AND THE CYTOKINE RESPONSE TO 2.5 H OF RUNNING

This randomized, double-blind, placebo-controlled study was designed t o determine the influence of 6% carbohydrate (C) vs. placebo (P) bever age ingestion on cytokine responses (5 total samples over 9 h) to 2.5 h of high-intensity running (76.7 +/- 0.4% maximal O-2 uptake) by 30 e xperienced marathon runners. For interleukin-g (IL-6), a difference in the pattern of change between groups was found, highlighted by a grea ter increase in P vs. C immediately postrun (753 vs. 421%) and 1.5 h p ostrun (193 vs. 86%) [F(4,112) = 3.77, P = 0.006]. For interleukin-l-r eceptor antagonist (IL-1ra), a difference in the pattern of change bet ween groups was found, highlighted by a greater increase in P vs. C 1. 5 h postrun (231 vs. 72%) [F(2,50) = 6.38, P = 0.003]. No significant interaction effects mere seen for bioactive IL-6 or IL-1 beta. The imm ediate postrun plasma glucose concentrations correlated negatively wit h those of plasma cortisol (r = -0.67, P < 0.001); postrun plasma cort isol (r = 0.70, P < 0.001) and IL-6 levels (r = 0.54, P = 0.003) corre lated positively with levels of IL-1ra. Taken together, the data indic ate that carbohydrate ingestion attenuates cytokine levels in the infl ammatory cascade in response to heavy exertion.