title: Cross-validation of an equating method linking aerobic FITNESSGRAM® field tests.
abstract: BACKGROUND
  Field tests measuring the same construct, in this case, aerobic capacity, use different scales, which makes fitness assessment of children and youth potentially confusing. The Primary Field Test Centered Equating Method has been developed to set tests on the same scale, as illustrated by the conversion of Progressive Aerobic Capacity Endurance Run (PACER) scores to 1-mile run/walk times to estimate VO(2)max.
  
  
  OBJECTIVE
  The purpose of this study was to cross-validate the Primary Field Test Centered Equating Method by using a data set of middle school students to assess its effectiveness.
  
  
  METHODS
  PACER scores of 135 middle school students were converted to 1-mile run/walk times (Mile PEQ) using the proposed method. Several estimates of VO(2)max using PACER scores were then compared to estimated VO(2)max using Mile PEQ and measured VO(2)max. The obtained measures were classified according to the healthy fitness zone (HFZ; FITNESSGRAM(®), version 9) and compared to measured VO(2)max. BMI estimates based on the sample data and the national average also were considered to assess the method's flexibility.
  
  
  RESULTS
  Agreement levels with actual values were similar for VO(2)max predicted using Mile PEQ and predictions using PACER laps and speed (73%-75%). The t-tests showed no significant difference between actual VO(2)max (M=44.43, SD= 8.36) and VO(2)max predicted using Mile PEQ (M=44.33, SD=5.88). Using BMI averages from sample data and the national data to estimate VO(2)max using Mile PEQ also yields high agreement levels, 70% and 73%, respectively.
  
  
  CONCLUSIONS
  The Primary Field Test Centered Equating Method performs as well or better in estimating VO(2)max as several other models using PACER scores, especially for boys, and thus may be successfully used in practice. More research is needed to understand the relatively low prediction and classification accuracy in girls.
authors.affiliation: Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA. e.boiarskaia@gmail.com
authors.forename: Elena A
authors.initials: EA
authors.lastname: Boiarskaia
authors.forename: Marco S
authors.initials: MS
authors.lastname: Boscolo
authors.forename: Weimo
authors.initials: W
authors.lastname: Zhu
authors.forename: Matthew T
authors.initials: MT
authors.lastname: Mahar
mesh_terms: D000293:Adolescent; D000367:Age Factors; D015992:Body Mass Index; D002648:Child; D005080:Exercise Test / Q000379:methods*; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D009657:North Carolina; D010101:Oxygen Consumption / Q000502:physiology*; D010807:Physical Endurance; D010809:Physical Fitness / Q000502:physiology*; D015203:Reproducibility of Results; D012420:Running; D012737:Sex Factors