title: Influence of acute plasma volume expansion on VO2 kinetics, VO2 peak, and performance during high-intensity cycle exercise.
abstract: The purpose of this study was to examine the influence of acute plasma volume expansion (APVE) on oxygen uptake (V(O2)) kinetics, V(O2peak), and time to exhaustion during severe-intensity exercise. Eight recreationally active men performed "step" cycle ergometer exercise tests at a work rate requiring 70% of the difference between the gas-exchange threshold and V(O2max) on three occasions: twice as a "control" (Con) and once after intravenous infusion of a plasma volume expander (Gelofusine; 7 ml/kg body mass). Pulmonary gas exchange was measured breath by breath. APVE resulted in a significant reduction in hemoglobin concentration (preinfusion: 16.0 +/- 1.0 vs. postinfusion: 14.7 +/- 0.8 g/dl; P < 0.001) and hematocrit (preinfusion: 44 +/- 2 vs. postinfusion: 41 +/- 3%; P < 0.01). Despite this reduction in arterial O(2) content, APVE had no effect on V(O2) kinetics (phase II time constant, Con: 33 +/- 15 vs. APVE: 34 +/- 12 s; P = 0.74), and actually resulted in an increased V(O2peak) (Con: 3.90 +/- 0.56 vs. APVE: 4.12 +/- 0.55 l/min; P = 0.006) and time to exhaustion (Con: 365 +/- 58 vs. APVE: 424 +/- 64 s; P = 0.04). The maximum O(2) pulse was also enhanced by the treatment (Con: 21.3 +/- 3.4 vs. APVE: 22.7 +/- 3.4 ml/beat; P = 0.04). In conclusion, APVE does not alter V(O2) kinetics but enhances V(O2peak) and exercise tolerance during high-intensity cycle exercise in young recreationally active subjects.
authors.affiliation: Department of Exercise and Sports Science, Manchester Metropolitan University, Alsager, UK.
authors.forename: Nicolas J A
authors.initials: NJ
authors.lastname: Berger
authors.forename: Iain T
authors.initials: IT
authors.lastname: Campbell
authors.forename: Daryl P
authors.initials: DP
authors.lastname: Wilkerson
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Jones
mesh_terms: D000328:Adult; D005080:Exercise Test; D017079:Exercise Tolerance / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D008297:Male; D008657:Metabolic Clearance Rate / Q000187:drug effects; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption / Q000187:drug effects / Q000502:physiology*; D005082:Physical Exertion / Q000187:drug effects / Q000502:physiology*; D010952:Plasma Substitutes / Q000008:administration & dosage*; D010953:Plasma Volume / Q000187:drug effects / Q000502:physiology*; D011097:Polygeline / Q000008:administration & dosage; D013647:Task Performance and Analysis
chemical_list: D010952:Plasma Substitutes; D011097:Polygeline; D010100:Oxygen