The purpose of this study was to determine the effects of exercise in hot, cold, and temperate environments on plasma interleukin-6 (IL-6). Eleven recreationally trained males (age = 25 ± 4 years, height = 178 ± 5 cm, weight = 79.4 ± 13.5 kg, body fat = 14.7 ± 3.6%, VO2 peak = 54.6 ± 11.5 ml kg-1 min-1) performed a 1 hr cycling bout in hot (33 °C), cold (7 °C), and temperate (20 °C) environments at 60% of Wmax followed by 3 hr of supine recovery in temperate conditions. Expired gases were measured every 15 min during exercise and once every hour during recovery. Heart rate was continuously measured throughout the trials. Blood samples were obtained from the antecubital vein pre-exercise, immediately post-exercise, and 3 hr post-exercise. Blood samples were analyzed for plasma concentrations of IL-6 using a commercial ELISA kit. Plasma IL-6 concentrations were significantly higher immediately post-exercise (14.8 ± 1.6 pg ml-1, p = 0.008) and 3 hr post-exercise (14.8 ± 0.9 pg ml-1, p = 0.018) compared to pre-exercise (11.4 ± 2.4 pg ml-1), across all trials. There were no differences in plasma IL-6 concentrations (p = 0.207) between temperature conditions.Oxygen consumption and heart rate were higher and respiratory exchange ratio was lower in the hot compared to other conditions (p < 0.05). These data indicate that the temperature in which exercise occurs does not affect acute plasma IL-6 response despite differences in metabolic state.
Dinan, Nicholas E.; Zak, Roksana B.; Shute, Robert J.; Laursen, Terry; Bubak, Matthew; La Salle, D. Taylor; Heesch, Matthew W.S.; and Slivka, Dustin R.
"Exercise-Induced Interleukin-6 and Metabolic Responses in Hot, Temperate, and Cold Conditions,"
Journal of Human Performance in Extreme Environments: Vol. 13
, Article 3.
Available at: http://docs.lib.purdue.edu/jhpee/vol13/iss1/3