LAUSR

INTRODUCTION Regular moderate-to-vigorous physical activity and high physical fitness are extremely important to the health of children and track to positive health profiles in adulthood. Family-based interventions to improve moderate-to-vigorous physical activity are essential given that children live within a structure of parental influence. The purpose of this study was to examine the effect of a parent planning skills intervention to support child physical activity on the subsequent moderate-to-vigorous physical activity (primary outcome) and fitness of their children across 26 weeks (primary endpoint). DESIGN Two-arm randomized trial with physical activity assessment at baseline 6 weeks, 13 weeks, and 26 weeks and fitness and BMI tests at baseline and 26 weeks from 2012 and 2017. SETTING/PARTICIPANTS One hundred and two children (aged 6-12 years) who were below international physical activity recommendations at baseline were recruited through advertisements. INTERVENTION Participants received a planning plus education intervention (n=52) or an education-only intervention (n=50). MAIN OUTCOME MEASURES Moderate-to-vigorous physical activity was assessed via accelerometry and fitness tests included aerobic fitness, muscular strength, flexibility. BMI was calculated by objectively assessed height and weight. RESULTS Generalized linear mixed modeling conducted in 2019 showed that the patterns varied by condition over time (β=-0.05, p<0.05), where children in the planning intervention significantly increased moderate-to-vigorous physical activity compared with the education condition at 6 weeks and 13 weeks but not at 26 weeks. Aerobic fitness (p=0.04, d=0.26) was the only significant health-related physical fitness change between the two groups and favored the planning group over the education group. CONCLUSIONS There was initial efficacy of the planning intervention, but effectiveness waned by 26 weeks. These changes appeared to be sufficient for modest changes in aerobic fitness. Future research should aim to improve the maintenance of these early positive changes and assist parents in planning for activities that also include opportunities to improve child musculoskeletal fitness. TRIAL REGISTRATION This study is registered at www.clinicaltrials.gov NCT01882192.