title: Metabolic effects of a protein-supplemented carbohydrate drink in marathon runners.
abstract: A field study was performed to investigate the acute influence of a milk protein hydrolysate supplemented drink (CHO+PRO) on metabolism during and after a marathon run compared to the same drink without protein (CHO). Carbohydrate metabolites and hormones were not influenced by CHO+PRO. Levels of plasma free fatty acids were significantly lower and levels of urea and most amino acids were significantly higher with CHO+PRO. Sweat urea and ammonia nitrogen excretion during the run as well as urinary 3-methylhistidine excretion during the entire exercise day was similar in both treatments. Urinary total nitrogen was significantly increased and urinary pH decreased with CHO+PRO. It was concluded that the supplemented protein was absorbed and probably at least partially oxidized during the run and that no obvious negative metabolic effects occurred. CHO+PRO did not acutely affect myofibrillar protein breakdown as assessed by the 3-methylhistidine method; however, total body protein breakdown was not measured.
authors.affiliation: INW Nutrition Biology, Swiss Federal Institute of Technology, CH-8092 Zurich, Switzerland. paolo.colombani@inw.agrl.ethz.ch
authors.forename: P C
authors.initials: PC
authors.lastname: Colombani
authors.forename: E
authors.initials: E
authors.lastname: Kovacs
authors.forename: P
authors.initials: P
authors.lastname: Frey-Rindova
authors.forename: W
authors.initials: W
authors.lastname: Frey
authors.forename: W
authors.initials: W
authors.lastname: Langhans
authors.forename: M
authors.initials: M
authors.lastname: Arnold
authors.forename: C
authors.initials: C
authors.lastname: Wenk
mesh_terms: D000328:Adult; D000596:Amino Acids / Q000008:administration & dosage / Q000097:blood; D000641:Ammonia / Q000032:analysis; D001628:Beverages; D018592:Cross-Over Studies; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D004044:Dietary Proteins / Q000008:administration & dosage*; D004311:Double-Blind Method; D004734:Energy Metabolism / Q000187:drug effects*; D015444:Exercise; D005230:Fatty Acids, Nonesterified / Q000097:blood; D006801:Humans; D008297:Male; D008762:Methylhistidines / Q000652:urine; D008894:Milk Proteins / Q000008:administration & dosage; D012420:Running; D013542:Sweat / Q000737:chemistry; D014508:Urea / Q000032:analysis / Q000097:blood
chemical_list: D000596:Amino Acids; D004040:Dietary Carbohydrates; D004044:Dietary Proteins; D005230:Fatty Acids, Nonesterified; D008762:Methylhistidines; D008894:Milk Proteins; D000641:Ammonia; D014508:Urea; C028118:3-methylhistidine