Hematological and Biochemical Responses During and After a 12-h Track Ultra-Marathon Race

Objectives: The purpose of the present study was to examine the acute effects on hematological, inflammatory, cellular, muscular, myocardial, liver, biliary, and humoral immunity biomarkers during and after a 12-h track ultra-marathon event. Methods: Twelve healthy male ultra-marathon runners completed the race and all measurements, including venous blood sampling performed before the race (PRE), at 6 h during the race (MID), and immediately after finishing (POST). Results: White blood cells, neutrophils, monocytes, basophils, and platelets increased at 6 h (MID) and remained elevated after the finish (POST), while eosinophils and lymphocytes decreased at mid-race and remained suppressed until post-race. The immunoglobulin G and C-reactive protein increased post-race compared to pre- and mid-race values, while lactate dehydrogenase and interleukin-6 increased at mid-race, with no further change until post-race. Creatine kinase, creatine kinase-MB, high-sensitivity cardiac troponin I, aspartate aminotransferase, and alanine aminotransferase significantly increased mid-race and showed a further significant increase post-race. Significant correlations were found between total distance covered and the percentage of PRE-MID difference of interleukin-6 and the percentage of PRE-POST difference of interleukin-6 and lactate dehydrogenase. Conclusions: The results of the present study indicate that participation in a 12-h track ultra-marathon is associated with marked exercise-induced alterations in multiple hematological and biochemical biomarkers, with several responses already evident at mid-race (6 h).