Device-Measured Change in Physical Activity in Primary School Children During the UK COVID-19 Pandemic Lockdown: A Longitudinal Study

BACKGROUND: Lockdown measures, including school closures, due to the COVID-19 pandemic have caused widespread disruption to children’s lives. The aim of this study was to explore the impact of a national lockdown on children's physical activity using seasonally-matched accelerometery data. METHODS: Using a pre/post observational design, 179 children aged 8-11 years provided physical activity data measured using hip worn tri-axial accelerometers worn for 5 consecutive days pre-pandemic and during the Jan-Mar 2021 lockdown. Multilevel regression analyses adjusted for covariates were used to assess the impact of lockdown on time spent in sedentary and moderate-to-vigorous physical activity (MVPA). RESULTS: A 10.8-minute reduction in daily time spent in moderate-to-vigorous physical activity (standard error [SE]: 2.3min/day, P<0.001), and a 33.2-minute increase in daily sedentary activity (SE: 5.5min/day, P<0.001) were observed during lockdown. This reflected a reduction in daily MVPA for those unable to attend school (-13.1±2.3 min/day, P<0,001) during lockdown, with no significant change for those who continued to attend school (0.4±4.0min/day, P<0.925). CONCLUSION: These findings suggest that the loss of in-person schooling was the single largest impact on physical activity in this cohort of primary school children in London, Luton and Dunstable UK.