Med Sci Sports Exerc 2022 Feb 21. Epub 2022 Feb 21.
Centre for Diet and Activity Research (CEDAR) & MRC Epidemiology Unit, University of Cambridge, Cambridge, UNITED KINGDOM School of Health Promotion and Human Performance, Eastern Michigan University, Ypsilanti, Michigan School of Heath Sciences, University of East Anglia, East Anglia, UNITED KINGDOM Norwegian School of Sport Sciences, Oslo, NORWAY School of Sports, Exercise and Health Sciences, Loughborough University, Loughborough, UNITED KINGDOM Faculty of Education, Arts and Sport, Western Norway University of Applied Sciences, Sogndal, NORWAY Health Research Institute, University of Canberra, Canberra, AUSTRALIA Federal University of Pelotas, Pelotas, BRAZIL Centre for Exercise, Nutrition & Health Sciences, School for Policy Studies, University of Bristol, UNITED KINGDOM Epidemiology, Biostatistics and Public Health Institute, University of Zürich, Zürich, SWITZERLAND Department of Sports Science and Clinical Biomechanics, Research Unit for Exercise Epidemiology, Centre of Research in Childhood Health, University of Southern Denmark, Odense, DENMARK Stanley Manne Children's Research Institute, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago Bristol Medical School, University of Bristol, Bristol, UNITED KINGDOM Department of Exercise Science, University of South Carolina, Columbia, SC Institute for Physical Activity and Nutrition & School of Exercise and Nutrition Sciences, Deakin University, Geelong, AUSTRALIA Exercise and Health Laboratory, CIPER, Faculty of Human Kinetics, Universidade de Lisboa, Lisbon, PORTUGAL.
Introduction: The United Kingdom and World Health Organization recently changed their youth physical activity (PA) guidelines from 60 minutes of moderate-vigorous PA (MVPA) every day, to an average of 60 minutes of MVPA per day, over a week. The changes are based on expert opinion due to insufficient evidence comparing health outcomes associated with different guideline definitions. This study used the International Children's Accelerometry Database to compare approaches to calculating youth PA compliance and associations with health indicators.
Methods: Cross-sectional accelerometer data (n = 21,612, 5-18y) was used to examine compliance with four guideline definitions: daily method (DM; ≥60 minutes MVPA every day), average method (AM; average of ≥60 minutes MVPA per day), AM5 (AM compliance and ≥ five minutes of vigorous PA [VPA] on ≥three days), AM15 (AM compliance and ≥ 15 minutes VPA on ≥three days). Associations between compliance and health indicators were examined for all definitions.
Results: Compliance varied from 5·3% (DM) to 29·9% (AM). Associations between compliance and health indicators were similar for AM, AM5, and AM15. For example, compliance with AM, AM5, and AM15 was associated with a lower BMI z-score (statistics are coefficient [95%CI]): AM (-0.28[-0.33,-0.23]), AM5 (-0.28[-0.33,-0.23], AM15 (-0.30[-0.35,-0.25]). Associations between compliance and health indicators for DM were similar/weaker, possibly reflecting fewer DM-compliant participants with health data and lower variability in exposure/outcome data.
Conclusions: Youth completing 60 minutes of MVPA every day do not experience superior health benefits to youth completing an average of 60 minutes of MVPA per day. Guidelines should encourage youth to achieve an average of 60 minutes of MVPA per day. Different guideline definitions impact inactivity prevalence estimates; this must be considered when analyzing data and comparing studies.