Related Experiment Video
Updated: Aug 5, 2026
Behavioral and Locomotor Measurements Using an Open Field Activity Monitoring System for Skeletal Muscle Diseases
Published on: September 29, 2014
The Medical College of Georgia Fitkid project: the relations between program attendance and changes in outcomes in
Z Yin1, J B Moore, M H Johnson
1Department of Health and Kinesiology, University of Texas San Antonio, San Antonio, TX 78249, USA. zenong.yin@utsa.edu
Objective:
To investigate the relations of attendance of children in an after-school physical activity (PA) program to changes in body composition and cardiovascular fitness (CVF).
Design:
Eight-month after-school PA-based intervention.
Subjects:
In all, 278 third-grade boys and girls from nine elementary schools (age, 8.7 y (s.d. = 0.6 y), body mass index (BMI) 19.1 kg/m2 (s.d. = 4.4) and percent body fat (%BF) 26.0 (s.d. = 9.0)).
Measurements:
Body composition (from dual-energy X-ray absorptiometry), BMI (from height and weight), waist circumference (WC) and CVF (from the YMCA submaximal bench-stepping test).
Results:
There was a significant negative linear trend between level of attendance in the after-school program and change in %BF and fat mass; there was also a significant positive linear trend between program attendance and change in CVF. There was a marginally significant linear trend between program attendance and fat-free mass. Greater increases in bone mineral density were observed with higher program attendance. Changes in BMI and WC were not influenced by program attendance.
Conclusion:
Understanding the dose-response effect of PA on health outcomes, particularly body composition, in children is crucial in our effort to prevent overweight and its health consequences. Since there is limited data available to base PA dose recommendations for youths, findings from this study are relevant, and suggest that greater health benefits can be obtained in young children with more frequent participation in PA.
