Muscle damage and inflammation biomarkers after two ultra-endurance mountain races of different distances: 54 km vs 111 km

The aims of this study were 1) to describe the effects of a 54 km and 111 km ultra-endurance mountain race on the biomarkers of muscle damage and inflammation, 2) to compare the effects between the two races regarding the biomarkers of muscle damage and inflammation. Sixteen ultra-endurance amateur runners volunteered to participate in this study. Ten runners completed a 54 km race (Group 1; age: 27.0 ± 5.7; height: 179.5 ± 5.8 cm; and body mass: 77.3 ± 10.7 kg) and six completed a 111 km race (Group 2; age: 30.5 ± 8.0; height: 179.4 ± 5.5 cm; and body mass: 76.2 ± 9.4 kg). Blood samples were taken at five different points during the investigation, 24 h before the race, immediately post-race, and again at 24, 48, and 72 h after the race. There were increases in leukocyte (Group 1: p ≤ .001, ES = 2.8; Group 2: p = .001, ES = 3.5) and platelet concentrations (Group 1: p ≤ .001, ES = 2.3; Group 2: p = .02, ES = 1.7) post-races. Significant inter-race differences were also observed in leukocyte at 72 h (Group 1: 5.5 ± 0.9, Group 2: 4.2 ± 0.9, p = .012, ES = 1.5). Erythrocytes, hematocrit and hemoglobin concentration decreased after 54 km and 111 km races at 24, 48 and 72 h (p ≤.001, ES = 2.0–3.18). Serum uric acid concentration increased after the 54 km race (pre = 4.9 ± 1.2 – post = 7.3 ± 1.0 8 mg/dl; p ≤ .001, ES = 2.4), and also the 111 km race (pre = 5.3 ± 0.9 – post = 6.7 ± 0.8 mg/dl; p