title: Construct validity and test-retest reliability of the International Fitness Scale (IFIS) in Spanish children aged 9-12 years.
abstract: We aimed to examine (a) the construct validity and reliability of the International Fitness Scale (IFIS) in children; and (b) the association of both self-reported and measured fitness with cardiometabolic risk. Cross-sectional study in 1145 Spanish children (9-12 years). We measured body fat, waist circumference, blood pressure, lipids, insulin, and fitness level (reported and measured). A validated cardiometabolic syndrome index was used. An age- and sex-matched sample of 245 children originally not included in the study sample fulfilled IFIS twice for reliability purposes. IFIS was able to correctly classify children according to their measured fitness levels (analysis of covariance, adjusted for sex and age was used). Test-retest reliability of IFIS items was also good, i.e., average weighted Kappa = 0.70. Our data also suggest that both measured and reported cardiorespiratory, and speed and agility fitness were associated with cardiometabolic risk factors, such as adiposity and a cardiometabolic syndrome risk score. The associations for muscular fitness (both reported and measured) differed depending on how it was expressed (i.e., absolute vs relative terms). Our findings suggest that self-reported fitness, as assessed by IFIS, is a valid, reliable, and health-related measure, and it can be a good alternative at population level when physical fitness cannot be measured.
authors.affiliation: Social and Health Care Research Centre, University of Castilla-La Mancha, Cuenca, Spain.|School of Education, University of Castilla-La Mancha, Ciudad Real, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Sánchez-López
authors.affiliation: Social and Health Care Research Centre, University of Castilla-La Mancha, Cuenca, Spain.
authors.forename: V
authors.initials: V
authors.lastname: Martínez-Vizcaíno
authors.affiliation: Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Talca, Chile.
authors.forename: A
authors.initials: A
authors.lastname: García-Hermoso
authors.affiliation: Department of Physical Education, School of Education, University of Cadiz, Puerto Real, Spain.
authors.forename: D
authors.initials: D
authors.lastname: Jiménez-Pavón
authors.affiliation: PROFITH "PROmoting FITness and Health through physical activity" research group, Department of Physical Education and Sports, Faculty of Sport Sciences, University of Granada, Granada, Spain.
authors.forename: F B
authors.initials: FB
authors.lastname: Ortega
mesh_terms: D050154:Adiposity; D001794:Blood Pressure; D002648:Child; D003430:Cross-Sectional Studies; D005080:Exercise Test; D018737:Hand Strength / Q000502:physiology; D006801:Humans; D007328:Insulin / Q000097:blood; D008055:Lipids / Q000097:blood; D010809:Physical Fitness / Q000502:physiology*; D015203:Reproducibility of Results; D018570:Risk Assessment; D012420:Running / Q000502:physiology; D057566:Self Report; D013030:Spain; D055105:Waist Circumference
chemical_list: D007328:Insulin; D008055:Lipids
keywords: Adiposity; cardiovascular diseases; physical fitness; risk factors; schoolchildren; self-report