Comparison of Changes in Biochemical Markers for Skeletal Muscles, Hepatic Metabolism, and Renal Function after Three Types of Long-distance Running: Observational Study

The purpose of this study is to compare changes in biochemical markers for the skeletal muscles, hepatic metabolism, and renal function based on extreme long-distance running. Among healthy amateur endurance athletes who participated in a marathon, 100 km-, or 308 km ultramarathon, 15 athletes with similar physical and demographic characteristics were chosen to be the subjects in this study, upon completion of each course. The subjects’ blood was collected before and after the course to identify biochemical markers for the skeletal muscles, hepatic metabolism, and renal function. After all of the courses, creatinine kinase (CK), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), alanine transaminase (ALT), blood urea nitrogen (BUN), and creatinine were found to be significantly increased compared with values obtained before the race (P <0.05 for each marker). CK, LDH, AST, and LDH were significantly higher after completion of the 100 km race than the marathon (P <0.05) and were significantly higher after the 308 km race than the marathon or 100 km race (P <0.05). Total protein was significantly lower after the 308 km race than the marathon or 100 km race (P <0.05). Albumin significantly increased after the marathon but significantly decreased after the 308 km course (P <0.05). Total and direct bilirubin were significantly increased after the 100 km and 308 km races (P <0.05), and were significantly higher after the 308 km than the marathon or 100 km course (P <0.05). BUN was significantly higher after the 100 km race than the marathon (P <0.05) and was significantly lower after the 308 km than the 100 km race (P <0.05). Creatinine was significantly higher after the marathon and 100 km than the 308 km race (P <0.05). Uric acid significantly increased after the marathon and 100 km race (P <0.05); it was significantly higher after completing the marathon and 100 km than the 308 km race (P <0.05). Muscular damage, decline in hepatic function, and hemolysis in the blood were higher after running a 308 km race, which is low-intensity running compared with a marathon, and a temporary decline in renal function was higher after completing a 100 km race, which is medium-to-high intensity.