Carbohydrate beverage ingestion and neutrophil degranulation responses following cycling to fatigue at 75% VO2max

Carbohydrate (CHO) beverage ingestion appears to influence neutrophil functional responses to prolonged exercise of a fixed duration. The aim of this randomised study was to examine the effect of CHO (5 % w/v) beverage ingestion on lipopoly-saccharide (LPS)-stimulated neutrophil degranulation responses in nine recreationally active males who cycled at 75 % VO2 max until fatigue. On two separate occasions, subjects ingested either placebo (PLA) or CHO beverages before and at 15 min intervals during the exercise. Subjects exercised for 31% longer on the CHO trial compared with the PLA trial (P<0.05). At fatigue plasma glucose concentration was significantly lower on the PLA trial compared with the CHO trial (P<0.05). Plasma cortisol concentrations had increased similarly on both trials at this time. A marked neutrophilia was evident at fatigue and throughout the 4h recovery period, the magnitude of which was similar on both trials. At fatigue LPS-stimulated elastase release per neutrophil had fallen similarly on both trials compared with pre-exercise values (47% and 50% on the PLA and CHO trials, respectively). In conclusion, our results suggest that CHO beverage ingestion has negligible influence on the hormonal, circulating neutrophil and LPS-stimulated neutrophil degranulation responses when exercise is performed to fatigue.