[Skip to Navigation]
August 3, 1984

Serum and Muscle Alanine Aminotransferase Activities in Marathon Runners

Author Affiliations

Hennepin County Medical Center University of Minnesota School of Medicine Minneapolis

JAMA. 1984;252(5):626-627. doi:10.1001/jama.1984.03350050018012

To the Editor.—  Marathon running has been shown to induce a variety of chemical changes in runners' serum.1 In the clinical laboratory, increases in serum alanine aminotransferase (ALT) activity have been shown to be very hepatospecific.2 Also, it has been suggested that ALT testing is potentially useful for screening blood donors to reduce incidence of non-A, non-B viral hepatitis.3,4 This report describes the changes in skeletal muscle and serum ALT activities in runners before and after a marathon race and discusses the potential for false biochemical indices for liver damage.Serum was obtained from 22 male (aged 21 to 36 years) and eight female (aged 24 to 35 years) runners two days before and 24, 48, 72, and 96 hours after a marathon race (26.2 miles). Gastrocnemius muscle biopsy specimens were obtained nine weeks before, two days before, and one day after the race from 14 male