title: Plasma activity of muscle enzymes: quantification of skeletal muscle damage and relationship with metabolic variables.
abstract: One hundred fourteen sedentary volunteers (34 +/- 8 years) took part in an endurance training study to be completed after 18-20 months with a marathon. Ultimately, 60 males and 18 females achieved that goal. The training program, carefully supervised, was divided into three periods with a maximum of 45-, 70-, and 110-km week training volume and concluded with a performance race of 15, 25, and 42.2 km, respectively. Three days before and 3 and 5 days after each race, 35 subjects were selected to perform a progressive treadmill test and the remaining subjects participated in field tests of 400 and 1000 m. A significant decrease in half-life time of CK enzyme plasma activity after running long distances in the course of the study from 20 h to 13 h was observed. Based on plasma enzyme activity and supposing that the total enzyme content left the muscle fiber, the estimated amount of muscle damage was found to be small. A gender difference in plasma enzyme activity increase (females demonstrated a lower increase) occurred only after the marathon.
authors.affiliation: Department of Human Biology/Institute Sportsmedicine Limburg, Maastricht, The Netherlands.
authors.forename: G M
authors.initials: GM
authors.lastname: Janssen
authors.forename: H
authors.initials: H
authors.lastname: Kuipers
authors.forename: G M
authors.initials: GM
authors.lastname: Willems
authors.forename: R J
authors.initials: RJ
authors.lastname: Does
authors.forename: M P
authors.initials: MP
authors.lastname: Janssen
authors.forename: P
authors.initials: P
authors.lastname: Geurten
mesh_terms: D000222:Adaptation, Physiological; D000328:Adult; D000410:Alanine Transaminase / Q000097:blood*; D001219:Aspartate Aminotransferases / Q000097:blood*; D003402:Creatine Kinase / Q000097:blood*; D005069:Evaluation Studies as Topic; D005260:Female; D006207:Half-Life; D006801:Humans; D008297:Male; D008875:Middle Aged; D009132:Muscles / Q000201:enzymology* / Q000293:injuries; D010807:Physical Endurance; D005082:Physical Exertion; D012420:Running / Q000293:injuries*
chemical_list: D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase; D003402:Creatine Kinase