Russell R. Pate, Gregory J. Welk and Kerry L. McIver
Natalie Colabianchi, Jamie L. Griffin, Kerry L. McIver, Marsha Dowda and Russell R. Pate
Numerous studies have focused on the role of environments in promoting physical activity, but few studies have examined the specific locations where children are active and whether being active in these locations is associated with physical activity levels over time.
Self-reported locations of where physical activity occurred and physical activity measured via accelerometry were obtained for a cohort of 520 children in 5th and 6th grades. Latent class analysis was used to generate classes of children defined by the variety of locations where they were active (ie, home, school grounds, gyms, recreational centers, parks or playgrounds, neighborhood, and church). Latent transition analyses were used to characterize how these latent classes change over time and to determine whether the latent transitions were associated with changes in physical activity levels.
Two latent classes were identified at baseline with the majority of children in the class labeled as ‘limited variety.’ Most children maintained their latent status over time. Physical activity levels declined for all groups, but significantly less so for children who maintained their membership in the ‘greater variety’ latent status.
Supporting and encouraging physical activity in a variety of locations may improve physical activity levels in children.
Karin A. Pfeiffer, Marsha Dowda, Kerry L. McIver and Russell R. Pate
This study examined correlates of objectively measured physical activity (PA) in a diverse sample of preschool children (age 3–5 years; n = 331). Accelerometer min·hr−1 of moderate-to-vigorous physical activity (MVPA) and nonsedentary activity (NSA) were the outcome measures. Correlations among potential correlates and PA ranged from r = −0.12−0.26. Correlates in the final MVPA model were age, race, sex, BMI Z score, and parent perception of athletic competence, explaining 37% of the variance. The NSA model included the latter two variables, explaining 35% of the variance. Demographic factors were correlates of PA; parent perceptions of children’s competence may be important regarding preschoolers’ PA.
Matthew T. Mahar, Gregory J. Welk, David A. Rowe, Dana J. Crotts and Kerry L. McIver
The purpose of this study was to develop and cross-validate a regression model to estimate VO2peak from PACER performance in 12- to 14-year-old males and females.
A sample of 135 participants had VO2peak measured during a maximal treadmill test and completed the PACER 20-m shuttle run. The sample was randomly split into validation (n = 90) and cross-validation (n = 45) samples. The validation sample was used to develop the regression equation to estimate VO2peak from PACER laps, gender, and body mass.
The multiple correlation (R) was .66 and standard error of estimate (SEE) was 6.38 ml·kg−1·min−1. Accuracy of the model was confirmed on the cross-validation sample. The regression equation developed on the total sample was: VO2peak = 47.438 + (PACER*0.142) + (Gender[m=1, f=0]*5.134) − (body mass [kg]*0.197), R = .65, SEE = 6.38 ml·kg–1·min–1.
The model developed in this study was more accurate than the Leger et al. model and allows easy conversion of PACER laps to VO2peak.