The effects of carbohydrate ingestion during endurance running on post-exercise inflammation and hepcidin levels

Abstract

The effect of carbohydrate (CHO) consumption during prolonged endurance running on post-exercise inflammation and hepcidin levels was investigated. Eleven well-trained male endurance athletes completed a graded exercise test, followed by two experimental running trials in a randomized order. The two experimental trials consisted of a 90 min run at 75% of the peak oxygen uptake velocity (vVO_2peak), while consuming a solution with either 6% CHO or a placebo (PLA) equivalent at 3 ml kg⁻¹ every 20 min. Serum interleukin-6 (IL-6), free hemoglobin (Hb), haptoglobin (Hp), hepcidin and iron parameters were assessed throughout the post-run recovery period. Serum iron and IL-6 were significantly elevated immediately post-run in both CHO and PLA (p ≤ 0.05), with no differences between trials. Serum-free Hb increased and Hp decreased significantly immediately post-run in both conditions (p ≤ 0.05). Serum soluble transferrin receptor levels were significantly below the baseline at 3 and 24 h post-run in both conditions (p ≤ 0.05). Serum hepcidin concentration recorded 3 h post-run in both conditions was significantly elevated (p ≤ 0.05), and had returned to the baseline by 24 h post-run (p ≤ 0.05). The use of a 6% CHO solution at 3 ml kg⁻¹ 20 min⁻¹ during endurance running did not attenuate the inflammatory response and subsequent increase in serum hepcidin levels during the post-run recovery period.