title: Validity and reliability of critical power field testing.
abstract: OBJECTIVE
  To test the validity and reliability of field critical power (CP).
  
  
  METHODS
  Laboratory CP tests comprised three exhaustive trials at intensities of 80, 100 and 105 % maximal aerobic power and CP results were compared with those determined from the field. Experiment 1: cyclists performed three CP field tests which comprised maximal efforts of 12, 7 and 3 min with a 30 min recovery between efforts. Experiment 2: cyclists performed 3 × 3, 3 × 7 and 3 × 12 min individual maximal efforts in a randomised order in the field. Experiment 3: the highest 3, 7 and 12 min power outputs were extracted from field training and racing data.
  
  
  RESULTS
  Standard error of the estimate of CP was 4.5, 5.8 and 5.2 % for experiments 1-3, respectively. Limits of agreement for CP were -26 to 29, 26 to 53 and -34 to 44 W for experiments 1-3, respectively. Mean coefficient of variation in field CP was 2.4, 6.5 and 3.5 % for experiments 1-3, respectively. Intraclass correlation coefficients of the three repeated trials for CP were 0.99, 0.96 and 0.99 for experiments 1-3, respectively.
  
  
  CONCLUSIONS
  Results suggest field-testing using the different protocols from this research study, produce both valid and reliable CP values.
authors.affiliation: Department of Life and Sport Science, University of Greenwich, Kent, ME4 4TB, UK, kb20@gre.ac.uk.
authors.forename: B
authors.initials: B
authors.lastname: Karsten
authors.forename: S A
authors.initials: SA
authors.lastname: Jobson
authors.forename: J
authors.initials: J
authors.lastname: Hopker
authors.forename: L
authors.initials: L
authors.lastname: Stevens
authors.forename: C
authors.initials: C
authors.lastname: Beedie
mesh_terms: D000328:Adult; D003627:Data Interpretation, Statistical; D005080:Exercise Test / Q000379:methods*; D017079:Exercise Tolerance; D006801:Humans; D008297:Male; D015203:Reproducibility of Results