A groundbreaking nationwide study reveals that relocating to a more walkable city can significantly increase daily steps and enhance moderate-to-vigorous exercise levels. This finding underscores urban design as a crucial factor in promoting public health. The study, published in the journal Nature, was conducted by researchers from the University of Washington, Stanford University, and their collaborators.
The research analyzed data from individuals across the United States, demonstrating that moving to more walkable cities resulted in sustained increases in daily steps. These gains persisted for at least three months and were evident across most age and gender groups, although the increase was not statistically significant for women over 50 years of age.
The Impact of Urban Walkability
The study’s results illustrate a clear pattern: when people moved to less walkable cities, their step counts dropped by amounts nearly identical to the gains seen when moving to more walkable areas. This symmetrical pattern highlights the significant role of urban design in influencing physical activity levels.
Physical inactivity is a global concern, contributing to major non-communicable diseases such as cancer, diabetes, and cardiovascular disease. With rapid urbanization projected to result in most people living in cities by 2050, the importance of urban design for public health is expected to increase.
Previous research has explored the links between the built environment, particularly walkability, and physical activity. However, findings have been inconsistent, with uncertainties about whether higher activity levels are driven by the environment or reflect personal preferences for active living.
Overcoming Research Limitations
Many prior studies faced limitations, including small sample sizes, restricted geographic coverage, and reliance on self-reported information, which can be biased. Additionally, cross-sectional study designs hinder causal inference, and self-selection related to residence choice can confound results.
To address these challenges, researchers utilized smartphones to continuously and objectively record both location and physical activity. This approach enabled large-scale, real-world analyses, revealing broad patterns in health behavior, urban mobility, and disease spread. It also exposed differences between device-based and self-reported physical activity measures.
Insights from the Study
The study analyzed nearly 250,000 days of step-count data from 5,424 US users of a smartphone app who moved at least once over three years, resulting in 7,447 moves between more than 1,600 cities. Step counts were recorded continuously via smartphone accelerometers, validated for accuracy in both lab and real-world settings.
Physical activity was measured for up to three months before and after each move, creating a large-scale natural experiment to assess the impact of changes in built environment walkability. Participants represented a range of body mass index (BMI), age, and gender categories. Relocations due to short-term travel were excluded, and sensitivity tests confirmed that results were robust to different definitions of relocation.
“Relocating to more walkable cities significantly increased daily steps, while moves to less walkable areas produced equivalent decreases. For example, moving from the 25th to the 75th percentile in walkability raised activity by approximately 1,100 steps per day, with changes sustained for at least three months.”
Climate differences did not derail the effect, as moving between cities with similar weather patterns still produced the expected step changes linked purely to walkability differences. The step increases were largely due to gains in moderate-to-vigorous physical activity (MVPA), defined as activity at a cadence of at least 100 steps per minute.
Challenges and Considerations
Older women faced unique hurdles, as they did not show significant increases in activity. Factors such as caregiving demands, potential wayfinding difficulties, and poor public transit access for non-commuters could be barriers needing extra support.
The study’s authors used a vast smartphone-derived dataset to separate environmental effects from individual preferences, quantifying how changes in walkability influence physical activity at both population and individual levels. The analysis included statistical tests and aggregated results across all relocations.
“Simulation models estimated that raising all US locations to the walkability level of Chicago or Philadelphia could result in 36 million more Americans meeting activity guidelines, while matching New York City’s level could increase this by 47 million.”
Policy Implications and Future Directions
The findings have strong policy implications, suggesting that improving walkability could substantially boost population-level physical activity, complementing individual-focused interventions. While achieving the walkability of highly walkable cities everywhere is unrealistic, targeted changes to urban design could yield significant health benefits.
The strengths of this analysis include the large, diverse dataset, longitudinal design, objective step measurement, and consistency of findings across climates, seasons, income levels, and demographic groups. However, limitations include potential bias toward higher socioeconomic status and health-conscious participants, restriction to US cities, and reliance on city-level walkability scores.
The study’s method also misses non-step-based activities and requires participants to carry their phones for data capture. However, the growing prevalence of smartphones and wearables should reduce such biases over time.
Ultimately, the results highlight walkability improvements as a scalable strategy for boosting population-level physical activity. This approach could be particularly effective if combined with age- and gender-specific strategies for groups like older women, who may face additional barriers to activity.
