Effects of ingestion of different amounts of carbohydrate after endurance exercise on circulating cytokines and markers of neutrophil activation

We aimed to examine the effects of ingestion of different amounts of carbohydrate (CHO) after endurance exercise on neutrophil count, circulating cytokine levels, and the markers of neutrophil activation and muscle damage. Nine participants completed three separate experimental trials consisting of 1 h of cycling exercise at 70% V⋅O2 max, followed by ingestion of 1.2 g CHO·kg body mass⁻¹·h⁻¹ (HCHO trial), 0.2 g CHO·kg body mass⁻¹·h⁻¹ (LCHO trial), or placebo (PLA trial) during the 2 h recovery phase in random order. Circulating glucose, insulin, and cytokine levels, blood cell counts, and the markers of neutrophil activation and muscle damage were measured. The concentrations of plasma glucose and serum insulin at 1 h after exercise were higher in the HCHO trial than in the LCHO and PLA trials. Although there were significant main effects of time on several variables, including neutrophil count, cytokine levels, and the markers of neutrophil activation and muscle damage, significant time × trial interactions were not observed for any variables. These results suggest that CHO ingestion after endurance exercise does not enhance exercise-induced increase in circulating neutrophil and cytokine levels and markers of neutrophil activation and muscle damage, regardless of the amount of CHO ingested.