title: Pictorial and verbal category-ratio scales for effort estimation in children.
abstract: BACKGROUND
  Research on the diverse aspects of exercise performance in childhood in the past 20 years has included an increase in the study of perceived exertion.
  
  
  OBJECTIVE
  The aim of this study was to compare children's ratings of effort perception by means of the Borg Category-Ratio Perceived Exertion (CR-10) Scale and a pictorial version of the Children's Effort Rating Table (Pictorial-CERT) scale, and to assess the long-term repeatability of the two scales.
  
  
  METHODS
  Fifty healthy children (25 girls and 25 boys; initially aged 10.4 +/- 0.5 years) participated in three incremental treadmill tests until volitional exhaustion or a maximal gradient of 22% at 5.4 km/h was attained. The first two tests (T1 and T2) were at an interval of 1 month. The third test (T3) took place 3 years later and utilized exactly the same protocol.
  
  
  RESULTS
  Perceived exertion correlated significantly with measures of exercise intensity - minute ventilation, heart rate and oxygen uptake for the whole group. The range of correlations for all tests was significantly higher for the Pictorial-CERT (r = 0.62-0.88 and r = 0.59-0.71 for the Pictorial-CERT and CR-10 respectively). Intraclass correlation coefficients between T1 and T2 were significantly higher for the Pictorial-CERT in comparison with the CR-10 (0.77 vs. 0.54, respectively; z = -2.07; P = 0.038).
  
  
  CONCLUSIONS
  The Pictorial-CERT is more appropriate for use with children of this age range and appears to be more reproducible than the Borg CR-10 Scale. Concurrent and construct validity evidence promotes the use of the Pictorial-CERT by junior children.
authors.affiliation: Department of Pathophysiology, Medical University of Plovdiv, Plovdiv, Bulgaria. b_marinov@mail.orbitel.bg
authors.forename: B
authors.initials: B
authors.lastname: Marinov
authors.forename: S
authors.initials: S
authors.lastname: Mandadjieva
authors.forename: S
authors.initials: S
authors.lastname: Kostianev
mesh_terms: D001296:Audiovisual Aids; D002648:Child; D005080:Exercise Test / Q000523:psychology; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology; D010465:Perception; D005082:Physical Exertion / Q000502:physiology*; D015203:Reproducibility of Results