title: The critical power concept in all-out isokinetic exercise.
abstract: The critical power concept has been applied to constant-load exhaustive exercise and recently validated for 3-min all-out exercise.
  
  
  OBJECTIVE
  To test the application of critical power to a 3-min all-out isokinetic cycling exercise.
  
  
  METHODS
  Single-group, experimental, comparative design.
  
  
  METHODS
  Nine participants performed a 3-min all-out isokinetic test and 4-5 constant-load exhaustive trials, at 60 and 100 rpm, on an electrically-braked cycle. The linear P-t-1 relationship was modelled using a 2-parameter model (slope: critical power; intercept: Anaerobic Work Capacity). End power and accumulated work done above EP were calculated from the 3-min tests.
  
  
  RESULTS
  No significant difference and a significant correlation was found between end power and critical power (60 rpm: 259 ± 40 W vs. 245 ± 38 W, P > 0.05; r = 0.85, P<0.01; 100 rpm: 227 ± 57 W vs. 212 ± 44 W, P > 0.05; r = 0.86, P<0.01). The Bias ± 95% limits of agreement were 14 ± 42 W at 60 rpm and 15 ± 57 W at 100 rpm. Work done above EP (60 rpm: 14.7 ± 3.0 kJ; 100 rpm: 17.3 ± 3.1 kJ) was not significantly different to the anaerobic work capacity (60 rpm: 16.2 ± 3.2 kJ; 100 rpm: 20.6 ± 6.4 kJ; P>0.05) but with only a significant correlation at 60 rpm (r = -0.71, P<0.05).
  
  
  CONCLUSIONS
  The 2-parameter model underpinning the critical power construct can be applied to a 3-min all-out isokinetic test. End power does not differ and correlates with critical power. However, a further insight into levels of agreement leads to some scepticism concerning the use of the two variables interchangeably. The great intra-subject differences between work done above EP and the intercept of the P-t-1 relationship should also be considered.
authors.affiliation: Department of Sport and Exercise Science, University of Brighton, Eastbourne, United Kingdom. Electronic address: j.dekerle@brighton.ac.uk.
authors.forename: Jeanne
authors.initials: J
authors.lastname: Dekerle
authors.affiliation: Department of Kinesiology, Kansas State University, Manhattan, USA.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Barstow
authors.affiliation: Department of Sport and Exercise Science, University of Brighton, Eastbourne, United Kingdom.
authors.forename: Luke
authors.initials: L
authors.lastname: Regan
authors.affiliation: Department of Sport and Exercise Science, University of Brighton, Eastbourne, United Kingdom.
authors.forename: Helen
authors.initials: H
authors.lastname: Carter
mesh_terms: D001642:Bicycling / Q000502:physiology; D001696:Biomechanical Phenomena; D015444:Exercise / Q000502:physiology*; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D010807:Physical Endurance; D055815:Young Adult
keywords: Cadence; Cycling; Endurance; Power–time relationship