We chose to compare changes in immune cell mobilisation and CRP level because they are reliable indicators of acute performance deterioration, muscle damage and/ or inflammation routinely evaluated in the general population and in athletes . The major finding was that a single exposure to WBCsignificantly alleviated inflammation after a strenuous Ponatinib Src-bcr-Abl inhibitor exercise run. i) Delta IL-1b was significantly suppressed 1 h after exercise following WBC, compared to the PAS condition ii) Delta IL-1ra increased 1 h and 24 h after exercise following WBC compared to PAS iii) CRP increase was strongly limited in the WBC group compared to the PAS group at 24 h and until 48 h after exercise. Principally, trail exercise will involve substantial uphill and downhill elements. The uphill tends to result in a greater exercise intensity and hence an increased metabolic cost . Conversely, downhill results in a lower metabolic cost than level and uphill walking at the same absolute speed , but it imposes greater forces on the lower limbs , resulting in greater eccentric loading. These eccentric muscle actions during downhill can result in temporary EIMD, which is manifested as reduced muscle function, muscle soreness , efflux of intramuscular enzymes, and limb swelling that may last for several days after the exercise bout . Within the injured muscle tissue there is leukocyte infiltration and local production of various pro- and anti-inflammatory cytokines which are crucial for initiating the breakdown and the subsequent removal of damaged muscle fragments . As expected, the present study demonstrates that trail exercise induces a significant release and peak of IL-6 and IL- 10 levels early after trail exercise compared to rest , followed by a rapid decrease toward pre-exercise, as demonstrated in previous studies . However there was no significant change in the plasma concentration of the proinflammatory cytokine TNF-a. This lack of change was consistent with a 42 km INCB18424 JAK inhibitor marathon and iron man race, suggesting that our population is well trained to this type of exercise . Moreover, the fact that the plasma level of TNF-a was not affected immediately after the trail exercise, might explain why the monocytes were also not activated by the exercise . It is also well established that high intensity exercise is associated with significant increases in circulating leukocytes during recovery . In the present study, leukocytes increase an average of 34% above resting level.