title: Plasma protein carbonyl response to increasing exercise duration in aerobically trained men and women.
abstract: The purpose of this study was to determine the effect of aerobic exercise duration on plasma protein carbonyl concentrations, a marker of protein oxidation, in aerobically trained men and women. Eight men (age: 27 +/- 4 years, VO (2peak): 4.09 +/- 0.26 L x min (-1); mean +/- SD) and 7 women (age: 27 +/- 6 years, VO (2peak): 2.33 +/- 0.24 L x min (-1)) exercised on an electrically-braked cycle ergometer at 70 % VO (2peak) for 30, 60 or 120 minutes on three separate days. Plasma samples collected before and immediately, 30- and 60-minutes post-exercise were analyzed for protein carbonyls. Mean oxygen uptake was greater for men in all conditions (2.75 +/- 0.03 L x min (-1); 38 +/- 0.43 ml x kg (-1) x min (-1)) compared to women (1.57 +/- 0.03 L x min (-1); 24.1 +/- 0.47 ml x kg (-1) x min (-1)). Total work performed during the exercise sessions was also greater for men than for women during the 30 (368 +/- 11 versus 223 +/- 7 kJ), 60 (697 +/- 17 versus 423 +/- 18 kJ), and 120-minute conditions (1173 +/- 44 versus 726 +/- 28 kJ) (Mean +/- SEM). Although these comparisons were significant (p < 0.0001), sex differences in total work performed and mean VO (2) did not result in sex differences in protein carbonyls. However, a condition by time interaction was observed with greater post-exercise values following the 120-minute condition compared to both the 30- and 60-minute conditions. Protein carbonyl concentration was greatest immediately post-exercise for both men and women and generally declined in a linear trend through one hour of recovery. These data suggest that protein carbonyl concentration is elevated by cycling exercise performed at 70 % VO (2peak), is greater following longer duration rides, begins to recover within one hour following exercise, and is not different between men and women.
authors.affiliation: Department of Exercise and Sport Science, University of North Carolina at Greensboro, Greensboro, NC 27402-6169, USA.
authors.forename: R J
authors.initials: RJ
authors.lastname: Bloomer
authors.forename: P G
authors.initials: PG
authors.lastname: Davis
authors.forename: L A
authors.initials: LA
authors.lastname: Consitt
authors.forename: L
authors.initials: L
authors.lastname: Wideman
mesh_terms: D000328:Adult; D001798:Blood Proteins / Q000032:analysis*; D016552:Ergometry; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology; D010807:Physical Endurance / Q000502:physiology*; D010809:Physical Fitness / Q000502:physiology*; D050050:Protein Carbonylation / Q000502:physiology*; D012737:Sex Factors; D013997:Time Factors
chemical_list: D001798:Blood Proteins