South Africans don’t walk as much as the world average
South Africans have some catching up to do when it comes to physical activity.
The biggest human movement study in history found that we take about 4,000 steps a day, 20% less than the global average of 5,000.
Data for the study came from the Azumio Argus smartphone app, which tracks activity and other factors that affect health, such as calorie intake.
Researchers combed through 68 million days of data from 717,527 users in 111 countries.
The study, published in Nature, followed a recent estimate that more than 5 million people die each year from causes linked to inactivity, aiming to come up with interventions to increase physical activity and reduce obesity.
"Big data is not just about big numbers, but also the patterns that can explain important health trends," said Grace Peng, director of the National Institute of Biomedical Imaging and Bioengineering computational modelling team at Stanford University in California.
The researchers focused on 46 countries, each with at least 1,000 users.
"The study is 1,000 times larger than any previous study on human movement," said team member Scott Delp.
"It tracks people's activity 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."
The researchers investigated the idea that creating cities that are safe and enjoyable to walk in could improve activity levels.
"If you must cross major highways to get from point A to point B in a city, the walkability is low; people rely on cars," Delp said.
"In cities like New York and San Francisco, where you can get across town on foot safely, the city has high walkability."
Higher walkability is associated with significantly more daily steps across all age, gender and body mass categories.
However, the researchers found that women recorded comparatively less activity than men in places that are less walkable.