BACKGROUND: The COVID-19 pandemic led to the implementation of worldwide restrictive measures to reduce social contact and viral spread . These measures have been reported to have a negative effect on physical activity (PA). Studies of PA during the pandemic have primarily used self-reported data . The single academic study that used tracked data did not report on demographics .
OBJECTIVE: This study aimed to explore patterns of smartphone-tracked activity before, during, and immediately after lockdown in the United Kingdom, and examine differences by sociodemographic characteristics and prior levels of PA.
METHODS: Tracked longitudinal weekly minutes of PA were captured using the BetterPoints smartphone app between January and June 2020 . Data were plotted by week, demographics, and activity levels at baseline . Nonparametric tests of difference were used to assess mean and median weekly minutes of activity at significant points before and during the lockdown, and as the lockdown was eased . Changes over time by demographics (age, gender, Index of Multiple Deprivation, baseline activity levels) were examined using generalized estimating equations (GEEs).
RESULTS: There were 5395 users with a mean age of 41 years (SD 12) and 61% (n=3274) were female . At baseline , 26% (n=1422) of users were inactive, 23% (n=1240) were fairly active, and 51% (n=2733) were active . There was a relatively even spread across deprivation deciles (31% [n=1693] in the least deprived deciles and 23% in the most [n=1261] ). We found significant changes in PA from the week before the first case of COVID-19 was announced (baseline) to the week that social distancing restrictions were relaxed (Friedman test: χ22=2331, P <.001). By the first full week of lockdown, the median change in PA was 57 minutes less than baseline . This represents a 37% reduction in weekly minutes of PA . Overall , 63% of people decreased their level of activity between baseline and the first week of COVID-19 restrictions . Younger people showed more PA before lockdown but the least PA after lockdown . In contrast, those aged> 65 years appeared to remain more active throughout and increased their activity levels as soon as lockdown was eased . Levels of PA among those classed as active at baseline showed a larger drop compared with those considered to be fairly active or inactive . Socioeconomic group and gender did not appear to be associated with changes in PA .
CONCLUSIONS: Our tracked PA data suggests a significant drop in PA during the United Kingdom's COVID-19 lockdown . Significant differences by age group and prior PA levels suggests that the government's response to COVID-19 needs to be sensitive to these individual differences and the government should react accordingly . Specifically, it should consider the impact on younger age groups, encourage everyone to increase their PA, and not assume that people will recover prior levels of PA on their own.