Mediating effects of resistance training skill competency on health-related fitness and physical activity: the ATLAS cluster randomised controlled trial

Abstract

The purpose of this study was to examine the mediating effect of resistance training skill competency on percentage of body fat, muscular fitness and physical activity among a sample of adolescent boys participating in a school-based obesity prevention intervention. Participants were 361 adolescent boys taking part in the Active Teen Leaders Avoiding Screen-time (ATLAS) cluster randomised controlled trial: a school-based program targeting the health behaviours of economically disadvantaged adolescent males considered “at-risk” of obesity. Body fat percentage (bioelectrical impedance), muscular fitness (hand grip dynamometry and push-ups), physical activity (accelerometry) and resistance training skill competency were assessed at baseline and post-intervention (i.e., 8 months). Three separate multi-level mediation models were analysed to investigate the potential mediating effects of resistance training skill competency on each of the study outcomes using a product-of-coefficients test. Analyses followed the intention-to-treat principle. The intervention had a significant impact on the resistance training skill competency of the boys, and improvements in skill competency significantly mediated the effect of the intervention on percentage of body fat and the combined muscular fitness score. No significant mediated effects were found for physical activity. Improving resistance training skill competency may be an effective strategy for achieving improvements in body composition and muscular fitness in adolescent boys.

Keywords:

• Adolescent
• movement skills
• overweight
• physical fitness
• physical activity

Acknowledgements

The authors thank Kerry Dally, Jo Salmon and Anthony Okely for their involvement in the design and delivery of the ATLAS study. The authors also thank Tara Finn, Sarah Kennedy, Emma Pollock and Mark Babic for their assistance with data collection. Finally, the authors are grateful to the schools, teachers, parents and study participants for their involvement.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by an Australian Research Council Discovery grant [grant number DP120100611]. Ronald C. Plotnikoff is supported by a National Health and Medical Research Council Senior Research Fellowship. David R. Lubans is supported by an Australian Research Council Future Fellowship.