[Skip to Navigation]
Views 363
Citations 0
Original Investigation
May 3, 2021

Effect of a Scalable School-Based Intervention on Cardiorespiratory Fitness in Children: A Cluster Randomized Clinical Trial

Author Affiliations
  • 1Institute for Positive Psychology and Education, Australian Catholic University, North Sydney, New South Wales, Australia
  • 2School of Behavioural and Health Sciences, Australian Catholic University, Banyo, Queensland, Australia
  • 3School of Behavioural and Health Sciences, Australian Catholic University, Strathfield, New South Wales, Australia
  • 4Faculty of Medicine and Health Sciences, Macquarie University, Macquarie Park, New South Wales, Australia
  • 5Priority Research Centre for Physical Activity and Nutrition, Callaghan, University of Newcastle, New South Wales, Australia
  • 6Institute for Physical Activity and Nutrition, Deakin University, Burwood, Victoria, Australia
  • 7Global Obesity Centre, Deakin University, Burwood, Victoria, Australia
  • 8Centre for Hip Health and Mobility, University of British Columbia, Vancouver, British Columbia, Canada
  • 9School of Health Sciences, Western Sydney University, Penrith, New South Wales, Australia
  • 10National School of Education, Australian Catholic University, Strathfield, New South Wales, Australia
  • 11School of Education and Social Work, Sydney University, Camperdown, New South Wales, Australia
  • 12School of Education, University of Wollongong, Wollongong, New South Wales, Australia
  • 13School of Education, University of Newcastle, Callaghan, New South Wales, Australia
  • 14School of Health and Social Development, Deakin University, Burwood, Victoria, Australia
  • 15New South Wales Department of Education, Turrella, New South Wales, Australia
  • 16Bouve College of Health Sciences, Northeastern University, Boston, Massachusetts
JAMA Pediatr. Published online May 3, 2021. doi:10.1001/jamapediatrics.2021.0417
Visual Abstract. Effect of a scalable school-based intervention on cardiorespiratory fitness in children: a cluster randomized clinical trial
Effect of a scalable school-based intervention on cardiorespiratory fitness in children: a cluster randomized clinical trial
Key Points

Question  Does an internet-based intervention for teachers improve children’s cardiorespiratory fitness when delivered across a large number of schools?

Findings  In this cluster randomized clinical trial of 22 schools including 1188 students, use of the internet-based intervention significantly improved children’s cardiorespiratory fitness at 12 months. Follow-up assessments at 24 months showed a sustained effect.

Meaning  Results of this randomized clinical trial suggest that the intervention has potential to be scaled to benefit children’s health at a population level.


Importance  Cardiorespiratory fitness is an important marker of childhood health and low fitness levels are a risk factor for disease later in life. Levels of children's fitness have declined in recent decades. Whether school-based physical activity interventions can increase fitness at the population level remains unclear.

Objective  To evaluate the effect of an internet-based intervention on children’s cardiorespiratory fitness across a large number of schools.

Design, Setting, and Participants  In this cluster randomized clinical trial, 22 government-funded elementary schools (from 137 providing consent) including 1188 students stratified from grades 3 and 4 in New South Wales, Australia, were randomized. The other schools received the intervention but were not included in the analysis. Eleven schools received the internet-based intervention and 11 received the control intervention. Recruitment and baseline testing began in 2016 and ended in 2017. Research assistants, blinded to treatment allocation, completed follow-up outcome assessments at 12 and 24 months. Data were analyzed from July to August 2020.

Interventions  The internet-based intervention included standardized online learning for teachers and minimal in-person support from a project mentor (9-10 months).

Main Outcomes and Measures  Multistage 20-m shuttle run test for cardiorespiratory fitness.

Results  Of 1219 participants (49% girls; mean [SD] age, 8.85 [0.71] years) from 22 schools, 1188 students provided baseline primary outcome data. At 12 months, the number of 20-m shuttle runs increased by 3.32 laps (95% CI, 2.44-4.20 laps) in the intervention schools and 2.11 laps (95% CI, 1.38-2.85 laps) in the control schools (adjusted difference = 1.20 laps; 95% CI, 0.17-2.24 laps). By 24 months, the adjusted difference was 2.22 laps (95% CI, 0.89-3.55 laps). The cost per student was AUD33 (USD26).

Conclusions and Relevance  In this study, a school-based intervention improved children's cardiorespiratory fitness when delivered in a large number of schools. The low cost and sustained effect over 24 months of the intervention suggests that it may have potential to be scaled at the population level.

Trial Registration  http://anzctr.org.au Identifier: ACTRN12616000731493

Limit 200 characters
Limit 25 characters
Conflicts of Interest Disclosure

Identify all potential conflicts of interest that might be relevant to your comment.

Conflicts of interest comprise financial interests, activities, and relationships within the past 3 years including but not limited to employment, affiliation, grants or funding, consultancies, honoraria or payment, speaker's bureaus, stock ownership or options, expert testimony, royalties, donation of medical equipment, or patents planned, pending, or issued.

Err on the side of full disclosure.

If you have no conflicts of interest, check "No potential conflicts of interest" in the box below. The information will be posted with your response.

Not all submitted comments are published. Please see our commenting policy for details.

Limit 140 characters
Limit 3600 characters or approximately 600 words