July 10 (UPI) -- Researchers at Stanford University are using smartphone technology and data to track the physical activity of more than 100 countries by population to measure their collective level of exercise.
The global study of daily step data from anonymous smartphone users shows how countries, genders and communities fare regarding physical activity, the researchers announced this week.
The study, published July 10 in Nature, used data smartphones to track the habits of 717,000 men and women from 111 countries over a 95-day period.
"The study is 1,000 times larger than any previous study on human movement," Scott L. Delp, a professor of bioengineering and director of the Mobilize Center at Stanford University, said in a press release.
"There have been wonderful health surveys done, but our new study provides data from more countries, many more subjects, and tracks people's activity on an ongoing basis in their free-living environments versus a survey in which you rely on people to self-report their activity. This opens the door to new ways of doing science at a much larger scale than we have been able to do before."
Researchers analyzed individuals' step records along with data on age, gender, height and weight status.
The study showed that, globally, the average user recorded roughly 5,000 steps a day.
The findings revealed that in countries with low obesity rates, people walked a similar amount each day, but in countries where large gaps existed between activity levels, there were high obesity levels.
"These results reveal how much of a population is activity-rich, and how much of a population is activity-poor," Delp said. "In regions with high activity inequality there are many people who are activity poor, and activity inequality is a strong predictor of health outcomes."
The wider gap between active and sedentary people may be an important target for obesity intervention in the future, according to researchers.
The study also found that in 69 U.S. cities, the higher the walkability scores, the lower the activity inequality resulting in lower obesity rates.
The study was funded by the National Institutes of Health.