Isolated Play

Worldwide Physical Activity Fell 27% in the Lockdown

Stay home, save lives! When the edict went out, speculation began immediately. How much will physical activity drop in the lockdown? What will be the unintended consequences? In Annals of Internal Medicine this week, we have a few answers. Based on step counts, physical activity dropped 27 percent worldwide in a sample of data from nearly half a million smartphones. But there was tremendous variation from city to city and country to country.

In fact, Italy saw a drop of 49 percent, while Sweden’s maximum drop was only seven percent. The U.S. fell in between those extremes with a drop of about 23 percent.

A Convenience Sample

In no way is this a projectable representation of the entire population of these countries. The data comes from a convenience sample of mostly (92%) iPhone users with an app called Argus. So people using other phones, other apps, no phones, or no apps just don’t count in these estimates. Nor does the possibility that people might have put their smartphones down when the lockdown began.

These limitations are real, but the data is nonetheless fascinating. It includes users from 187 countries all around the world.

Regional Variations

It’s fascinating to see how different the patterns of step counts are in different countries and different cities. With its light-touch lockdown, the minimal impact in Sweden is unsurprising. But another country with minimal impact was South Korea, which took very aggressive measures to control virus spread. At most, the average step counts went down by ten percent there. By early June, South Korea had fully recovered. In contrast, step counts from Brazil dropped fast and were still down by 40 percent in June.

Turning to the U.S., step counts fell the most and recovered the slowest in New York. In Dallas, folks simply did not slow down as much. However, it’s worth noting that step counts all across cities in the U.S. remain lower than they were before the lockdown.

Impact on Health

It’s a pretty good bet that the worldwide drop in physical activity during the lockdown will have an impact on health. And in fact, we may witness the collision of two pandemics – physical inactivity and COVID-19. That’s the thesis of Grenita Hall and colleagues. Writing for Progress in Cardiovascular Diseases, they tell us a pandemic of physical inactivity will persist long after the world recovers from COVID-19.

It will take a concerted effort to get us moving again and without that, global health will continue to suffer.

Click here for the Tison study and here for further reporting on it. For the commentary by Hall et al, click here. Finally, you can find an overview of an excellent collection of articles on this subject here.

Isolated Play, photograph © Nikita Nikiforov / flickr

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July 1, 2020