Pre-exercise carbohydrate status influences carbohydrate-mediated attenuation of post-exercise cytokine responses

Most studies investigating the effects of acute carbohydrate (CHO) ingestion on post-exercise cytokine responses have involved fasted athletes. This study characterised the effects of acute CHO beverage ingestion preceded by consumption of a CHO-containing pre-exercise meal. Sixteen highly-trained male cyclists/triathletes (age: 30.6±5.6y; V̇O_2max: 64.8±4.7 ml·kg·min^-1 [mean ± SD]) undertook two cycle ergometry trials involving randomised consumption of a 10% CHO beverage (15 mL·kg^-1·hr^-1) or water (H₂O). Trials were undertaken 2 h after a breakfast providing 2.1 g CHO·kg^-1 body mass (BM) (48 kJ·kg^-1 BM) and consisted of 100 min steady state cycle ergometry at 70% V̇O_2max followed by a time trial of ∼30 min duration. Blood samples were collected pre-, post- and 1 h post-exercise for measurement of Interleukin (IL)-6, IL-8, IL-10 and IL-1ra. Time-trial performance was not substantially different between CHO and H₂O trials (4.5%, p = 0.42). Neither IL-6 nor IL-8 responses were substantially reduced in the CHO compared to the H₂O trial. There was a substantial reduction in IL-10 (32%, p = 0.05) and IL-1ra (43%, p = 0.02) responses at 1 h post-exercise with CHO compared to H₂O ingestion. In conclusion, the previously shown attenuating effects of CHO ingestion during exercise on cytokine responses appear reduced when athletes consume a CHO-containing pre-exercise meal.