Body Mass and PACER Performance Among Hispanic Youth

Purpose: The purpose of this study was to examine the influence mass and gender would have on PACER shuttle laps completed among Hispanic children.

Methods: A total sample of 339 Hispanic children participated in this study, with 239 randomly assigned to the validation group and 110 to the cross validation group. All participants were measured (height, mass, percent fat, and sum of skinfolds) and completed a 20-m PACER shuttle test.

Analysis/Results: Multiple regression was used to develop a model for estimating the number of PACER laps completed from body mass and gender for the validation group (n=239). Gender was dummy coded (0=females, 1=males) in the regression analysis. Homogeneity of regression slope and intercept was used to determine if a single model could be used to estimate the number of laps completed for Hispanic boys and girls. Final phase of the analysis was to cross-validate the derived model. The following equation: SEE= √Σ(y-y')²/n was used to calculate the standard error of estimate (SEE) on the cross validation group. Physical characteristics of the boys (n=128) and girls (n=101) in the validation group were (mean±SD): age(yr)= 10.6±0.9 , 10.6±1.0; body mass(kg)= 47.7±15.3, 48.3±12.9; PACER laps completed= 27.2±10.0, 20.6±11.5; VO_2max(ml^.kg^-1.min^-1) = 36.0±7.3, 29.6±4.1, respectively. Based upon results of the regression analysis, the following model was derived: laps completed = 43.426 + (Mass[kg] x -0.471) + (boys = 6.428 or girls = 0). The statistically significant model (p<.001) was accurate in estimating PACER laps completed (R = .498, SEE = 13.3 laps). The test for homogeneity of regression slope and intercept revealed a common regression slope and different intercepts for estimating laps completed for Hispanic boys and girls. The derived model was then cross-validated. Physical characteristics of the boys (n=60) and girls (n=50) in the cross-validation group were (mean±SD): age(yr)= 10.6±1.0, 10.4±1.0; body mass(kg)= 43.91±4.2, 47.5±11.8; PACER laps completed= 25.9±15.0, 19.2±11.8; VO_2max(ml^.kg^-1.min^-1)= 36.2±6.5, 29.44±.3, respectively. The derived model demonstrated similar accuracy (R = .426, SEE= 14.8 laps) in estimating laps completed for the cross-validation group. Conclusions: This study revealed that for every kilogram of body mass, Hispanic children ran approximately 0.5 fewer laps. Controlling for body mass, Hispanic boys completed approximately 6.5 more PACER laps than girls. In conclusion, the negative influence of body mass on PACER performance can be quantified for Hispanic youth.