title: Effects of priming exercise on VO2 kinetics and the power-duration relationship.
abstract: OBJECTIVE
  This study aimed to investigate the influence of prior heavy- and severe-intensity exercise on the oxygen uptake (V·O₂) kinetics and the power-duration relationship.
  
  
  METHODS
  Ten cyclists performed 13 exercise tests during a 4-wk period, consisting of a ramp test to determine the gas exchange threshold (GET) and the peak V·O₂, followed by a series of square-wave tests to exhaustion under three conditions: no prior exercise (control), prior heavy exercise (6 min at a work rate above GET but below critical power [CP)], and prior severe exercise (6 min at a work rate above the CP). Pulmonary gas exchange was measured throughout the exhaustive exercise bouts and the parameters of the power-duration relationship (CP and the curvature constant, W') were determined from the linear work-time model.
  
  
  RESULTS
  Prior heavy exercise increased the amplitude of the primary V·O₂ response (by ∼ 0.19 ± 0.28 L·min(-1), P = 0.001), reduced the V·O₂ slow component trajectory (by 0.04 ± 0.09 L·min(-2), P = 0.002), and increased the time to exhaustion (by ∼ 52 ± 92 s, P = 0.005). The CP was unchanged (control vs prior heavy: 284 ± 47 vs 283 ± 44 W; 95% confidence interval, -7 to 5 W), whereas the W' was increased by heavy-intensity priming (16.0 ± 4.8 vs 18.7 ± 4.8 kJ; 95% confidence interval, 0.3-5.2 kJ). Severe-intensity exercise had a similar effect on the V·O₂ kinetics but had no effect on the time to exhaustion, the CP (275 ± 45 W), or the W' (16.7 ± 4.7 kJ).
  
  
  CONCLUSIONS
  Prior heavy-intensity exercise primes the V·O₂ kinetics and increases the amount of work that can be performed above the CP.
authors.affiliation: Department of Sport and Exercise Science, Aberystwyth University, Ceredigion, United Kingdom. mhb@aber.ac.uk
authors.forename: Mark
authors.initials: M
authors.lastname: Burnley
authors.forename: Glen
authors.initials: G
authors.lastname: Davison
authors.forename: Jonathan Robert
authors.initials: JR
authors.lastname: Baker
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology; D000328:Adult; D001642:Bicycling / Q000502:physiology*; D017079:Exercise Tolerance / Q000502:physiology*; D006801:Humans; D008297:Male; D053580:Muscle Strength / Q000502:physiology*; D010101:Oxygen Consumption / Q000502:physiology*; D005082:Physical Exertion / Q000502:physiology; D055815:Young Adult