JMIR Publications

ABSTRACT

Background:

Physical distancing measures taken to contain the coronavirus disease 2019 (COVID-19) transmission may substantially reduce physical activity levels and cause individuals to adopt a more sedentary lifestyle.

Objective:

To describe change in daily steps, an important component of daily physical activity, and examine risk factors for frequent low daily steps around the COVID-19 epidemic.

Methods:

We used data collected from the Step Study, a population-based longitudinal study of walking activity among residents aged ≥40 years in Changsha, China. Daily steps were collected via smartphone linked to WeChat, a social-network platform. We plotted mean daily steps and the prevalence of low daily steps (≤1,500 steps/day) 30 days before (reference period) and 30 days after (epidemic period) January 21, 2020 (date of the first COVID-19 case diagnosed in Changsha), and compared it with the same corresponding period from 2019. We examined the relation of risk factors for the prevalence of frequent low daily steps (≤1,500 steps/day for ≥14 days) using logistic regression.

Results:

Among 3,544 participants (mean age: 51.6 years; females: 34.6%), mean daily steps dropped from 8,097 to 5,440 and the prevalence of low daily steps increased from 3% to 18.5%, during reference and epidemic periods, respectively. No such phenomenon was observed during the corresponding period in 2019. Older age and female sex were both associated with higher prevalence of frequent low daily steps and were more pronounced during the epidemic period (P for interaction<.01). More education was associated with a lower prevalence of frequent low daily steps during the reference period but not the epidemic period (P for interaction=.34). Body mass index or comorbidity was not associated with frequent low daily steps during either period.

Conclusions:

Daily steps of residents aged ≥40 years during the COVID-19 period in Changsha dropped significantly, especially among the old adults and females. While successful physical distancing, measured by the rapid downward trend in daily step counts of residents, played a critical role in the containment of COVID-19 epidemic, our findings of an increase in prevalence of frequent low daily steps raise concerns about unintended effects on physical activity.