Change in outdoor walking behavior during the coronavirus disease pandemic in Japan: A longitudinal study

BACKGROUND: Due to the high infectivity and seriousness of coronavirus disease, people’s daily activities were restricted in countries worldwide; governments implemented lockdown measures and advised individuals to perform self-restraint in terms of leaving the house. However, there have been few scientific reports on the effects of such behavioral restrictions on walking parameters. RESEARCH QUESTION: Did behavioral restrictions during the state of emergency in Japan effect walking parameters in daily life outdoor walking? METHODS: In this retrospective cohort study, four walking parameters, namely, the average number of steps taken, walking speed, step length, and cadence, were measured using a smartphone application among 3901 participants (mean age ± standard deviation: 60.3 ± 28.9 years) from March 2 to June 15 in both 2019 and 2020. Repeated-measures two-way analysis of variance was used to compare the walking parameters between the two years. RESULTS: The number of steps significantly decreased (p < .001) in 2020 (∼3400 steps) compared to that in 2019 (∼4400 steps), indicating that the state of emergency greatly affected the amount of physical activity performed per individual. Conversely, walking speed increased (p < .001 during the period when the state of emergency was issued) in 2020 (∼1.25 m/s) compared to that in 2019 (∼1.23 m/s), attributable to an increased step length. SIGNIFICANCE: Although changes in walking speed and step length were small compared to those in the number of steps, those changes were consistently seen during the state of emergency, suggesting that people tried to walk faster in their outdoor walking. Such change in walking behavior may have protected further deterioration of health due to restricted activity.