Acute long-distance trail running increases serum IL-6, IL-15, and Hsp72 levels.

IL-6, Hsp72, and IL-15 are molecules that have significant metabolic effects on glucose and fat metabolisms and cell's stress response. The aim of this study is to determine their serum levels after a long-distance trail run. Serum IL-15 levels after such endurance events have not been investigated yet. Blood samples were collected from 37 athletes (11 female, 26 male) before and after a 35-km trail run, with a total climb of 940m. Serum was obtained from the samples and IL-6, IL-15 and Hsp72 levels were measured from serum by sandwich ELISA method. The athletes completed the race in 308.3 ± 37.4 minutes on average. After the race, the mean serum IL-6, IL-15 and Hsp72 concentrations increased 13.2 fold, 2.22 fold and 1.6 fold respectively (p<0.001, p<0.001 and p<0.039). This is the first study to demonstrate the increase in serum IL-15 levels following an acute endurance exercise. In addition to IL-15, we report that IL-6 and sHsp72 levels also increase significantly following a 35-km trail run. Since these molecules involve in regulating effects on glucose and fat metabolism, significant increases of IL-6, IL-15 and sHsp72 may have health benefits that may be associated with long-distance trails which are becoming more popular worldwide.