Paule Barbeau

Physical training improves insulin resistance syndrome markers in obese adolescents

INTRODUCTION The purpose of this study was to test the hypothesis that physical training (PT), especially high-intensity PT, would have a favorable effect on components of the insulin resistance syndrome (IRS) in obese adolescents. METHODS Obese 13- to 16-yr-olds (N = 80) were randomly assigned to one of the following 8-month interventions; 1) lifestyle education (LSE)-alone every 2 wk, 2) LSE+moderate-intensity PT, and 3) LSE+high-intensity PT. PT was offered 5 d x wk(-1). Plasma triacylglycerol (TAG), total cholesterol (TC), high-density lipoprotein cholesterol (HDLC), very low-density lipoprotein cholesterol (VLDLC), low-density lipoprotein cholesterol (LDLC), low-density lipoprotein (low density lipoprotein (LDL)) particle size, apolipoproteins AI and B, glucose, insulin, and blood pressure were measured with standardized methods. RESULTS The intent-to-treat analyses for all subjects who completed pre- and post-tests regardless of their adherence to the interventions showed that the LSE+high-intensity PT group had more favorable changes than the LSE-alone group in TAG level (P = 0.012), TC/HDLC (P = 0.013), and diastolic blood pressure (P = 0.031). For efficacy analyses, all PT subjects who attended at least 2 d x wk(-1) (40%) were combined into one group (LSE+PT) and compared with the LSE-alone group. These two-group analyses showed significant interactions (P < 0.001) between baseline values and group membership for deltaTAG, deltaVLDLC, and deltaTC/HDLC, such that subjects who had the least favorable baseline values showed the most beneficial impact of the PT. Of particular interest was a favorable effect of the PT on LDL particle size. CONCLUSION PT, especially high-intensity PT, had a favorable effect on several IRS markers in obese adolescents.

Ten months of exercise improves general and visceral adiposity, bone, and fitness in black girls.

Objective: The goal of this study was to evaluate the impact of a 10‐month after‐school physical activity (PA) program on body composition and cardiovascular (CV) fitness in young black girls.

Preliminary findings of the effect of a 3-year after-school physical activity intervention on fitness and body fat: The Medical College of Georgia Fitkid Project

OBJECTIVE To evaluate the effect of a 3-year after-school physical activity (PA) intervention on aerobic fitness and percent body fat (%BF). METHODS In total, 18 schools were randomized into intervention or control arms. Measurements were made at the beginning and end of the third, fourth and fifth grades. Fitness was measured with heart rate response to a bench-stepping task.%BF and bone density were measured with dual-energy x-ray absorptiometry. The intervention included 40 min of academic enrichment activities, during which healthy snacks were provided, and 80 min of moderate-to-vigorous PA (MVPA). RESULTS Data analyses were performed on 206 youths who remained in the same schools for the 3-year period, who were measured at all six time points and, for the intervention group, who attended at least 40% of the sessions in each of the 3 years. The group by time interactions were significant for fitness (p < 0.01) and %BF (p < 0.05). Children in intervention schools improved in fitness and %BF during the school years and returned to levels similar to those in control schools during the summers. Over the six measurement points, the intervention group increased more than the control group in bone density (p < 0.01), fat-free soft tissue (p < 0.01), weight (p < 0.01), height (p < 0.01), and body mass index (p < 0.05). CONCLUSIONS An after-school program focusing on MVPA had a beneficial effect on fitness and body composition. During the summers, the beneficial effect of the previous years participation on fitness and %BF was lost. This highlights the importance of year-round programs to promote healthy growth in youths.

Measuring Enjoyment of Physical Activity in Children: Validation of the Physical Activity Enjoyment Scale

This study sought to determine the reliability and validity of the Physical Activity Enjoyment Scale (PACES) in elementary school children. The sample consisted of 564 3rd grade students (M age = 8.72 ±.54; 268 male, 296 female) surveyed at the beginning of the fall semester. Results indicated that the PACES displayed good internal consistency and item-total correlations. Confirmatory factor analyses supported a unidimensional factor structure. Scores on the PACES were significantly correlated with task goal orientation (r = .65, p < .01), athletic competence (r = .23, p < .01), physical appearance (r = .20, p < .01), and self-reported physical activity (r = .16, p < .01). However, results of invariance analysis suggested the factor structure is variant across sex. The present findings suggest support for the validity of the PACES as a valid measure of enjoyment of physical activity in children; nevertheless, further research examining the invariance of the factor structure across sex is warranted.

Cost-Effectiveness of a School-Based Obesity Prevention Program

BACKGROUND A school-based obesity prevention study (Medical College of Georgia FitKid Project) started in the fall of 2003 in 18 elementary schools. Half of the schools were randomized to an after-school program that included moderate-to-vigorous physical activity, healthy snacks, homework assistance, and academic enrichment. All third graders were invited to enroll. The objective of this study was to assess the cost-effectiveness (CE) of the first-year intervention. METHODS Standard CE analysis methods and a societal perspective were used. Program delivery costs incurred during the first-year intervention and the usual after-school care costs that would occur in the absence of the intervention were estimated (in 2003 dollars). Net intervention costs were calculated by subtracting the usual after-school care costs from the intervention costs. The effectiveness of the intervention was measured as percent body fat (%BF) reduction compared with a control condition. The CE was assessed as the net intervention cost divided by the effectiveness of the intervention. RESULTS The intervention costs totaled

General and visceral adiposity in black and white adolescents and their relation with reported physical activity and diet.

174,070,

Dissecting the genetic architecture of the cardiovascular and renal stress response.

558/student, or

Relationship of Visceral Adiposity to Cardiovascular Disease Risk Factors in Black and White Teens

956/student who attended > or = 40% of the intervention sessions. The usual after-school care costs were estimated at

An After-School Physical Activity Program for Obesity Prevention in Children The Medical College of Georgia FitKid Project

639/student. Students who attended > or = 40% of the intervention reduced %BF by 0.76% (95% confidence interval: -1.42 to -0.09) at an additional cost of

The Medical College of Georgia Fitkid Project : the relations between program attendance and changes in outcomes in year 1

317/student. CONCLUSIONS Subjects who attended > or = 40% of the intervention achieved a significant reduction in %BF at a relatively low cost. School-based obesity prevention programs of this type are likely to be a cost-effective use of public funds and warrant careful consideration by policy makers and program planners.