Bio-psycho-social correlates of physical fitness in childhood and adolescence

Abstract

Introduction: Although children and youth currently form the most active segments of the population in the westernized world, there is amarked trend towards an increase in sedentary lifestyle and a decrease in physical fitness among school-age children. In order to counteractthe suspected degradation, potential determinants must be known. Previous studies are based on non-representative samplesmostly and are only conditionally comparable. Therefore, reliable findings on the determinants of physical fitness are not available. Thepurpose of the study is the identification of correlates of physical fitness in childhood and adolescence. It is assumed that physical fitnessis associated with intrapersonal, behavioural and ecological factors.Method: Data were obtained from the “Luxembourg project”, a representative sample of the 9, 14- and 18-year-old boys and girls fromLuxembourg (N = 1188). Physical fitness was measured on the basis of ten motor description categories such as aerobic endurance andflexibility by using a standardised test profile. Intrapersonal (e.g. BMI, sports interest), behavioural (e.g. extent of physical activity; p.a.) andecological (e.g. peer-group behaviour, socio-economic status; ses) factors were assessed by using a standardised questionnaire (cf. Böset al., 2006).Results: Ten multiple regression equations with sequential entry of the model levels help to confirm the suspected relation for eight out often motor description categories. Percentage of declared total variance is between 8.0% (fine motor abilities on precision tasks; F=5.19;p=.000; adjusted R²=.080) and 58.1% (speed of force development in lower extremities; F=67.70; p=.000; adjusted R²=.581). The identifiedeffects and their directions can be clarified by the example of gross motor abilities under time pressure (F=35.98; p=.000; adjustedR²=.241). The performance in jumping sideways rises with increasing age (Beta=.64; T=17.52; p=.000), sports interest (Beta=.12; T=4.19;p=.000) and ses (Beta=.10; T=3.51; p=.000) as well as under the influence of an increased extent of p.a. in sports club (Beta=.15; T=5,10;p=.000), whereas lower performances become obvious with increasing BMI (Beta=-.12; T=-3.95; p=.000).PerspectivesThe results delimit the spectrum of potential correlates of physical fitness. However, the related design does not permit any causal conclusions.To receive reliable statements about the determinants of motor development in childhood and adolescence, the individualsincluded here will be examined prospectively in the context of a longitudinal section study.