Stanford University researchers, in a large-scale study funded by the National Institutes of Health, report that they have tracked the physical activity by population in more than 100 countries, using daily step data from participants’ smartphones.
Results from the study, published recently in Nature, reveal targets for obesity prevention and the wisdom of walkable communities.
Globally, the average user recorded about 5,000 steps per day. The smartphone data reflected the degree of difference, or inequality, for activity among people within a given country. By comparing countries with more uniform activity patterns and those with unequal activity, certain patterns and health dynamics emerged. For instance, countries with the greatest activity inequality are also the countries with the greatest obesity problem.
They studied a dataset consisting of 68 million days of physical activity for 717,527 people, giving them a window into activity in 111 countries across the globe. The researchers found inequality in how activity is distributed within countries and that this inequality is a better predictor of obesity prevalence in the population than average activity volume. Reduced activity in females contributes to a large portion of the observed activity inequality. Aspects of the built environment, such as the walkability of a city, are associated with a smaller gender gap in activity and lower activity inequality. In more walkable cities, activity is greater throughout the day and throughout the week, across age, gender, and body mass index (BMI) groups, with the greatest increases in activity found for females. The findings have implications for global public health policy and urban planning and highlight the role of activity inequality and the built environment in improving physical activity and health.
Physical Activity across de world (Source: Nature)
This study presents a new paradigm for population activity studies by demonstrating that smartphones can deliver new insights about key health behaviours.