Energy metabolism, liver and kidney function in adolescent marathon runners

Background To study parameters of energy metabolism, liver and kidney function in adolescent runners completing a standard 42.2-km marathon run. Design Observational field study. Materials and methods Fifty adolescents (30 healthy males and 20 healthy females) aged between 13 and 17 years participated in the study. All participants underwent routine medical screening. Blood samples were taken before, at the end and 24 h after a competitive marathon to investigate parameters of metabolism, liver and kidney function. Results Forty-seven runners completed the race with a mean finishing time of 4 h 57 min 24 s (range: 3 h 17 min 09 s to 6 h 14 min 01 s). None of the participants experienced an adverse medical event during or postmarathon. Findings indicate predominant lipid oxidation during and postmarathon, signs of minor hepatic injury and only transiently reduced kidney function caused by marathon running in adolescents. Conclusion The observed findings are very similar to those reported in healthy adults. There is no evidence of liver or kidney injury in adolescent runners participating in a standard marathon run.