title: Determination of critical power using a 3-min all-out cycling test.
abstract: OBJECTIVE
  We tested the hypothesis that the power output attained at the end of a 3-min all-out cycling test would be equivalent to critical power.
  
  
  METHODS
  Ten habitually active subjects performed a ramp test, two 3-min all-out tests against a fixed resistance to establish the end-test power (EP) and the work done above the EP (WEP), and five constant-work rate tests to establish the critical power (CP) and the curvature constant parameter (W') using the work-time and 1/time models.
  
  
  RESULTS
  The power output in the 3-min trial declined to a steady level within 135 s. The EP was 287 +/- 55 W, which was not significantly different from, and highly correlated with, CP (287 +/- 56 W; P = 0.37, r = 0.99). The standard error for the estimation of CP using EP was approximately 6 W, and in 8 of 10 cases, EP agreed with CP to within 5 W. Similarly, the WEP derived from the 3-min test (15.0 +/- 4.7 kJ) was not significantly different from, and correlated with, W' (16.0 +/- 3.8 kJ; P = 0.35; r = 0.84).
  
  
  CONCLUSIONS
  During a 3-min all-out cycling test, power output declined to a stable value in approximately the last 45 s, and this power output was not significantly different from the independently measured critical power.
authors.affiliation: Department of Sport and Exercise Science, University of Wales, Aberystwyth, United Kingdom.
authors.forename: Anni
authors.initials: A
authors.lastname: Vanhatalo
authors.forename: Jonathan H
authors.initials: JH
authors.lastname: Doust
authors.forename: Mark
authors.initials: M
authors.lastname: Burnley
mesh_terms: D000328:Adult; D015308:Anaerobic Threshold / Q000502:physiology*; D001642:Bicycling / Q000502:physiology*; D005080:Exercise Test; D006801:Humans; D008297:Male; D009119:Muscle Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D010101:Oxygen Consumption / Q000502:physiology*; D005082:Physical Exertion / Q000502:physiology*; D011446:Prospective Studies; D013997:Time Factors