STABILITY IN PHYSICAL FITNESS. A STUDY ON BELGIAN MALES FOLLOWED LONGITUDINALLY FROM 12 TO 30 YEARS.

Abstract

1732 The purposes of this study were (1) to establish the stability for individual differences in several physical fitness indicators, and (2) to present the quasisimplex strategy for the analysis of this problem. The sample comes from the Leuven Longitudinal Study on Lifestyle, Fitness and Health. For this study a sub-sample of 100 males was chosen, followed longitudinally and measured at mean ages of 12.7, 13.7, 14.6, 15.6, 16.7, 17.7 and 30 years. The physical fitness assessments included: arm pull, bent arm hang, plate tapping, sit and reach, shuttle run and vertical jump. In field reliability for these tests are ranged between 0.63<r<0.91. Data analysis for this multiwave panel design consists of auto-regressive quasi-simplex models as suggested by Joreskog & Sorbom (1970) and Maia et al. (1997). Calculations were performed independently for each indicator of physical fitness. Results are of three types: global fit measures (χ2, RMSEA, CFI), explained variance for structural equations (R2), stability estimates (β) which are functional dependencies of fitness indicators, say, from time 3 to time 2, and tracking coefficients (r) which are disattenuated auto-correlations. Global fit measures for each model of multiwave motor tests are within accepted bounds (χ2<31.69, p>0.04; RMSEA<0.11; CFI>0.95); explained variance of the structural equations for the dependency of fitness indicators of agej on agei is 0.40<R2<0.97; stability coefficients are high and statistically significant, 0.63<β<0.98, and tracking coefficients between the seven time points are within the range of 0.34<r<0.98. In conclusion: (1) auto regressive quasi-simplex models are well suited for the analysis of stability of physical fitness indicators; (2) models fit the data well with a variance accounted for by greater than 40%; (3) stability estimates of motor tests showed high values(β >0.63), and tracking coefficients for each indicator, exclusively from age 12.7 to age 30 are within the bounds of 0.34 to 0.64.