Activity Inequality

Activity Inequality Project

Smartphone data from over 68 million days of activity by 717,527 individuals across 111 countries reveal variability in physical activity across the world.

The variance of activity around the population mode differs between countries. Curves show distribution of steps across the population relative to the population mode. In Japan, the activity of 76% of the population falls within 50% of the mode (i.e., between white dashed lines), whereas in Saudi Arabia this fraction is only 62%. The United Kingdom and United States lie between these two extremes for average activity level and variance.

Activity inequality predicts obesity. Individuals in the five countries with highest activity inequality are 196% more likely to be obese than individuals from the 5 countries with lowest activity inequality.

Aspects of the built environment, such as walkability, may mitigate activity inequality. Higher walkability scores are associated with lower activity inequality based on data from 69 United States cities.

Paper

Research paper in Nature (547.7663)
Paper PDF
Paper Supplementary Information

Abstract: Understanding the basic principles that govern physical activity is needed to curb the global pandemic of physical inactivity and the 5.3 million deaths per year associated with inactivity. Our knowledge, however, remains limited owing to the lack of large-scale measurements of physical activity patterns across free-living populations worldwide. Here, we leverage the wide usage of smartphones with built-in accelerometry to measure physical activity at planetary scale. We study a dataset consisting of 68 million days of physical activity for 717,527 people, giving us a window into activity in 111 countries across the globe. We find 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, were associated with less gender gap in activity and 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 for females. Our findings have implications for global public health policy and urban planning and highlight the role of activity inequality and the built environment for improving physical activity and health.

Data

We analyzed 68 million days of physical activity based on smartphone measurements from 717,527 people in 111 countries across the globe.

Our data and code are available at Github.

Countries by Activity Inequality

We rank countries by activity inequality where lower values correspond to a more equal distribution of physical activity (using the Gini coefficient ranging from 0 to 1).

The following table and more data are also available here.

Rank	Country	Activity Inequality
1	Hong Kong	22.2
2	China	24.5
3	Sweden	24.6
4	South Korea	24.7
5	Czech Republic	24.8
6	Japan	24.8
7	Singapore	24.9
8	Norway	25.2
9	Ukraine	25.2
10	Netherlands	26.1
11	Spain	26.1
12	Taiwan	26.2
13	Denmark	26.2
14	Russia	26.2
15	Chile	26.3
16	Switzerland	26.3
17	Turkey	26.4
18	Finland	26.6
19	Germany	26.6
20	France	26.8
21	Poland	26.9
22	Brazil	27.2
23	Israel	27.2
24	Thailand	27.2
25	Hungary	27.3
26	Italy	27.5
27	Portugal	27.6
28	Belgium	27.6
29	Mexico	27.9
30	United Arab Emirates	28.1
31	Indonesia	28.3
32	Romania	28.3
33	South Africa	28.4
34	Ireland	28.5
35	Malaysia	28.8
36	United Kingdom	28.8
37	Qatar	29.1
38	India	29.3
39	Greece	29.5
40	Philippines	29.8
41	New Zealand	30.1
42	United States	30.3
43	Egypt	30.3
44	Canada	30.3
45	Australia	30.4
46	Saudi Arabia	32.5

Team

Media

Press information:
Stanford Press Release
NIH Press Release
HiRes images

Press kit available upon request.
Direct inquiries to Tim Althoff.

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