Your neighborhood can make you healthier

They say the path is made by walking, but some neighborhoods make it easier. Moving to a place that encourages walking can radically change your physical activity, increasing it by up to an hour a week. This is the finding of a macro-study published this Wednesday in the scientific journal Nature . The authors used a huge database: the data accumulated over three years by two million people on a step-counting app. They then focused on all those users who had moved during this period, some 5,500, and looked for changes in their activity patterns.

“Comparing the same person’s activity before and after moving is key to understanding whether it’s the environment or the people themselves that determine how much they walk,” explains Tim Althoff , a professor of computer science at the University of Washington and co-author of the study. Ultimately, it seems that the environment plays a crucial role. Flaneurs , those romantic Parisian strollers identified by Charles Baudelaire, would buy an SUV and drive into traffic if they had to move to the sprawl of a modern city.

Neighborhood walkability was measured using the Walk Score, an index that takes into account proximity to shops and services, block length, and intersection density ( you can see your neighborhood's Walk Score here ). New York City, for example, has a score of 89 out of 100. The 178 people who moved from a neighborhood with a low score of 48/100 to this city increased their physical activity by 1,400 steps, going from a daily average of 5,600 to 7,000 steps. A person should walk between 7,000 and 10,000 steps a day to reap health benefits, according to the World Health Organization. It's an increase that has an impact on health, and the best part is that it adds up. "This adds about an hour of physical activity per week," Althoff says.

Furthermore, Althoff explains, the fact that the walks weren't recreational, but rather had a purpose (going to work, shopping, running errands) caused pedestrians to speed up their pace. "Not all steps are created equal; our study shows that the additional activity is primarily brisk walking, which is the moderate-to-vigorous intensity exercise doctors recommend for disease prevention."

The benefits of walking are well known. Nearly 70% of people who visit their primary care doctor in Spain do not achieve the minimum recommended level of healthy activity: 150 minutes per week . The mortality rate among active people is reduced by 30% to 60% compared to those who are not, and exercise reduces the incidence, to a greater or lesser extent, of virtually all diseases. The best possible medicine is not in the pharmacy but on the street. And adapting neighborhoods to this evidence should be a priority.

Adherence to these habits proved to be very high, and the changes after the move were maintained over the months. It's much easier to integrate walking to buy bread every day into your routine than going all out at CrossFit a couple of times a week (although, obviously, it doesn't burn as many calories).

The changes in activity patterns shown in the study held true across gender, age, and body mass index (BMI). There was one exception: women over 50. It may be that other factors, such as public safety (which was not taken into account in the study), had a stronger impact on this population segment. Or there may have been other reasons. “Our study couldn't fully answer this question,” Althoff acknowledges. “However, my coauthor and colleague Abby King at Stanford University has done extensive work in this area to help us understand the specific barriers this group faces, such as cultural norms, caregiving demands, or physical challenges. Overall, this is a crucial finding that tells us a one-size-fits-all approach isn't enough.”

The European city

The Nature macro-study focuses on the Anglo-Saxon context, but its conclusions can be extrapolated to European cities. “I grew up in Germany and often miss the walkable design and public transport infrastructure of European cities,” Althoff acknowledges before going on to explain the genesis of these differences. “Most European cities evolved over centuries, long before the mass production of automobiles. This history resulted in a dense, compact, mixed-use urban fabric. American cities were more influenced by the rise of the automobile. This led to a different approach to urban planning, which prioritized vehicle traffic over pedestrian and cyclist movement.”

The great irony is that, although we now know more about how we should create healthier neighborhoods, we rarely apply this theoretical knowledge to practice. In Spanish cities, 68% of public space is dedicated to cars and only 32% is for pedestrians. This figure drops to 25% in the newly built urban periphery.

For years, efforts have been underway to make cities more accessible for walking. This includes building more human-sized neighborhoods, but also pedestrianizing areas, filling them with shade and greenery. Promoting plazas that create spaces for intergenerational coexistence. In Spain, for example, the Ministry of Health commissioned a group of experts to create the Guide to Planning Healthy Cities . One of them is Esther Higueras , architect, urban planner, and professor at the Polytechnic University of Madrid.

"I don't know if they pay much attention to us," she admits sarcastically. The expert asserts that doctors, epidemiologists, and urban planners have been warning for decades about the type of city that should be built. "But then there are other factors, like the real estate market or people's tastes, like they want a small house with a pool 50 kilometers from work in a new neighborhood." The expert asserts that the ideal (although complicated) approach would be to walk to work. Only 17% of Spaniards do so, according to a survey by the National Institute of Statistics .

Higueras welcomes the Nature study and explains that it confirms something they've been seeing for some time. "If you want people to go out and walk, the street has to be attractive. It has to be safe, it has to have wide sidewalks, good thermal conditions, there has to be shade, there has to be greenery." In Europe, we're fortunate that our cities have a solid foundation, a dense, compact, mixed-use city structure. These changes, he explains, should be easier to implement. And they would be a necessary long-term investment in public health. "Look at the urban expansions of large cities, for example. Many people who were young started buying houses in these areas, without services or small businesses, with a heavy reliance on cars. But now these people are starting to not be so young, they're not walking at all, and the problems begin. And this raises the question: what will happen when they get older? That's going to be a major problem."

Manuel Franco , a research epidemiologist at the Universities of Alcalá and Johns Hopkins, also positively evaluates the Nature study. Speaking to the scientific website SCM Spain, he explains that "it is of very good quality and its design is very interesting." Franco emphasizes that the analysis focuses on people's daily activities, an area in which public interventions can have a significant impact. "Physical activity is always confused with sports or leisure activities, and not with the physical activity we do for the sake of moving around or commuting. It's based on how we carry out our daily tasks," he points out.

Focusing on this could save many problems in the long run. Urban planning is a powerful public health tool, those interviewed agree. As Althoff summarizes, "Investing in sidewalks, safe crossings, and mixed-use zoning that brings parks and shops closer to homes isn't just an amenity. It's a direct investment in the health of citizens."