title: Comparison of inter-trial recovery times for the determination of critical power and W' in cycling.
abstract: Critical Power (CP) and W' are often determined using multi-day testing protocols. To investigate this cumbersome testing method, the purpose of this study was to compare the differences between the conventional use of a 24-h inter-trial recovery time with those of 3 h and 30 min for the determination of CP and W'.
  
  
  METHODS
  9 moderately trained cyclists performed an incremental test to exhaustion to establish the power output associated with the maximum oxygen uptake (p[Formula: see text]max), and 3 protocols requiring time-to-exhaustion trials at a constant work-rate performed at 80%, 100% and 105% of p[Formula: see text]max.Design: Protocol A utilised 24-h inter-trial recovery (CP24/W'24), protocol B utilised 3-h inter-trial recovery (CP3/W'3), and protocol C used 30-min inter-trial recovery period (CP0.5/W'0.5). CP and W' were calculated using the inverse time (1/t) versus power (P) relation (P = W'(1/t) + CP).
  
  
  RESULTS
  95% Limits of Agreement between protocol A and B were -9 to 15 W; -7.4 to 7.8 kJ (CP/W') and between protocol A and protocol C they were -27 to 22 W; -7.2 to 15.1 kJ (CP/W'). Compared to criterion protocol A, the average prediction error of protocol B was 2.5% (CP) and 25.6% (W'), whilst for protocol C it was 3.7% (CP) and 32.9% (W').
  
  
  CONCLUSIONS
  3-h and 30-min inter-trial recovery time protocols provide valid methods of determining CP but not W' in cycling.
authors.affiliation: a Department of Life and Sport Science , University of Greenwich , Kent , UK.
authors.forename: Bettina
authors.initials: B
authors.lastname: Karsten
authors.affiliation: b School of Sport and Exercise Sciences , University of Kent , Kent , UK.
authors.forename: James
authors.initials: J
authors.lastname: Hopker
authors.affiliation: c Department of Sport & Exercise , University of Winchester , Hampshire , UK.
authors.forename: Simon A
authors.initials: SA
authors.lastname: Jobson
authors.affiliation: d Department of Sport and Exercise Science , Aberystwyth University , Wales , UK.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Baker
authors.affiliation: a Department of Life and Sport Science , University of Greenwich , Kent , UK.
authors.forename: Luca
authors.initials: L
authors.lastname: Petrigna
authors.affiliation: e Westfälische Wilhelms-Universität Münster , Arbeitsbereich für Sportpädagogik , Münster , Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Klose
authors.affiliation: f School of Human and Life Sciences , Canterbury University , Kent , UK.
authors.forename: Christopher
authors.initials: C
authors.lastname: Beedie
mesh_terms: D054874:Athletic Performance / Q000502:physiology*; D001642:Bicycling / Q000502:physiology*; D005080:Exercise Test / Q000379:methods*; D006801:Humans; D018763:Muscle Fatigue / Q000502:physiology; D010101:Oxygen Consumption / Q000502:physiology; D013997:Time Factors
keywords: Critical intensity; anaerobic work capacity; exercise testing; power-duration relationship; validity