title: Reliability of fitness tests using methods and time periods common in sport and occupational management.
abstract: BACKGROUND
  Fitness testing is used frequently in many areas of physical activity, but the reliability of these measurements under real-world, practical conditions is unknown.
  
  
  OBJECTIVE
  To evaluate the reliability of specific fitness tests using the methods and time periods used in the context of real-world sport and occupational management.
  
  
  METHODS
  Cohort study.
  
  
  METHODS
  Eighteen different Cirque du Soleil shows.
  
  
  METHODS
  Cirque du Soleil physical performers who completed 4 consecutive tests (6-month intervals) and were free of injury or illness at each session (n = 238 of 701 physical performers).
  
  
  METHODS
  Performers completed 6 fitness tests on each assessment date: dynamic balance, Harvard step test, handgrip, vertical jump, pull-ups, and 60-second jump test.
  
  
  METHODS
  We calculated the intraclass coefficient (ICC) and limits of agreement between baseline and each time point and the ICC over all 4 time points combined.
  
  
  RESULTS
  Reliability was acceptable (ICC > 0.6) over an 18-month time period for all pairwise comparisons and all time points together for the handgrip, vertical jump, and pull-up assessments. The Harvard step test and 60-second jump test had poor reliability (ICC < 0.6) between baseline and other time points. When we excluded the baseline data and calculated the ICC for 6-month, 12-month, and 18-month time points, both the Harvard step test and 60-second jump test demonstrated acceptable reliability. Dynamic balance was unreliable in all contexts. Limit-of-agreement analysis demonstrated considerable intraindividual variability for some tests and a learning effect by administrators on others.
  
  
  CONCLUSIONS
  Five of the 6 tests in this battery had acceptable reliability over an 18-month time frame, but the values for certain individuals may vary considerably from time to time for some tests. Specific tests may require a learning period for administrators.
authors.affiliation: Cirque du Soleil, Las Vegas, NV, USA.
authors.forename: Bryan D
authors.initials: BD
authors.lastname: Burnstein
authors.forename: Russell J
authors.initials: RJ
authors.lastname: Steele
authors.forename: Ian
authors.initials: I
authors.lastname: Shrier
mesh_terms: D000328:Adult; D015331:Cohort Studies; D005080:Exercise Test / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D010809:Physical Fitness; D015203:Reproducibility of Results; D013177:Sports