Timing of post-exercise carbohydrate ingestion: influence on IL-6 and hepcidin responses

Eur J Appl Physiol. 2015 Oct;115(10):2215-22. doi: 10.1007/s00421-015-3202-0. Epub 2015 Jun 18.


Purpose: Carbohydrate ingestion prior and during exercise attenuates exercise-induced interleukin-6. This investigation examined if an analogous effect was evident for interleukin-6 and hepcidin response when carbohydrates were ingested post-exercise.

Methods: In a crossover design, 11 well-trained endurance athletes completed two experimental trials. Participants completed an 8 × 3 min interval running session at 85 % vVO2peak followed by 5 h of monitored recovery. During this period, participants were provided with two 1.2 g kg(-1) carbohydrate beverages at either an early feeding time (immediately post-exercise and 2 h post-exercise) or delayed feeding time (2 h post-exercise and 4 h post-exercise). Venous blood samples were collected pre-, immediately post-, 3 and 5 h post-exercise. Samples were analysed for Interleukin-6, serum iron, serum ferritin and hepcidin.

Results: Interleukin-6 was significantly elevated (p = 0.004) immediately post-exercise compared to baseline for both trials. Hepcidin levels were significantly elevated at 3 h post-exercise (p = 0.001) and 5 h post-exercise (p = 0.002) compared to baseline levels in both trials, with no significant difference between the two conditions and any time point. Serum iron was significantly increased from baseline to immediately post-exercise (p = 0.001) for both trials, with levels decreasing by 3 h (p = 0.025) and 5 h post-exercise (p = 0.001). Serum ferritin levels increased immediately post-exercise compared to baseline (p = 0.006) in both conditions.

Conclusions: The timing and ingestion of post-exercise carbohydrate ingestion do not appear to impact post-exercise interleukin-6 and hepcidin responses; this is likely a result of the interval running task inducing an inflammatory response and subsequent up-regulation of hepcidin.

Keywords: Cytokine; Interval running; Iron metabolism; Nutrition.

MeSH terms

  • Adolescent
  • Adult
  • Dietary Carbohydrates / administration & dosage
  • Dietary Carbohydrates / pharmacology*
  • Drug Administration Schedule
  • Eating
  • Exercise*
  • Hepcidins / blood*
  • Humans
  • Interleukin-6 / blood*
  • Iron / blood
  • Male
  • Physical Endurance / drug effects


  • Dietary Carbohydrates
  • Hepcidins
  • Interleukin-6
  • Iron