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HEALTH DISPARITY

Tanzanian children are the world’s fittest while American kids are among the least

According to a new study, Tanzanian kids are among the world's fittest while Americans are among the least.
Reuters/Radu Sigheti
Healthy kids make healthy adults.
Published This article is more than 2 years old.

Tanzanian, Icelandic, Estonian, Norwegian and Japanese children are the world’s fittest while Mexican, Peruvian, Latvian, and American kids are the least fit. That’s according to a new study by Justin Lang, a PhD candidate at the University of Ottawa, published in the British Journal of Sports Medicine.

Lang and researchers from Australia and the United States analyzed how children between the ages of 9 and 17 in 50 countries performed on a 20 meter (66 feet) running test, known in Australia as the “beep test.” The children run as many 20-meter shuttles back and forth as they can at an increasingly fast pace, as a way to measure their maximum aerobic power.

Looking at the aerobic capacity of children is important for the overall population’s health. “Kids who are aerobically fit tend to be healthy; and healthy kids are apt to be healthy adults,” said Lang.

"International variability in 20 m shuttle run performance in children and youth," Justin Lang, Mark S Tremblay, and researcher.

Lang and his colleagues also found that, in developing countries, when certain socioeconomic indicators improved, performance on the running test worsened. In developed countries, the opposite was the case.

For instance, the higher a developing country’s level of urbanization or “human development index”—a score based on quality of life and prosperity—the worse its kids performed on the test.

This, according to Lang, is an indication of a society in the middle of a “physical activity transition,” the point when a population becomes wealthier and is able to expend less energy on things like getting food or commuting.

“The evidence of a physical activity transition is similar to a double-edged sword,” Lang said. ”The difference in developing countries is that these transitions are occurring at a rapid rate and developing countries simply don’t have the infrastructures in place to cope with the burden of chronic disease in addition to the prevalent infectious diseases in these parts of the world,” he said.

It’s hard to say exactly how many countries are going through this transition, according to Lang. But Africa, which has the world’s second fastest rate of urbanization after Asia, and where pockets of a middle class are expanding, may be especially vulnerable.

Among all countries though, Lang and his researchers found that higher income inequality was accompanied by lower performance on the test.

“Countries with a large gap between rich and poor often have large subpopulations of extremely poor individuals. Poverty is linked to bad health outcomes—one of which is aerobic fitness.”

CountryCentile rank
Tanzania97
Iceland93
Estonia92
Norway87
Japan84
Denmark80
Czech Republic77
Finland77
Côte d’Ivoire75
Morocco74
France72
Lithuania70
Benin70
Djibouti68
Mauritius68
Slovakia65
Germany65
Senegal64
Canada63
Turkey63
United Kingdom62
Poland62
Suriname62
Beligium61
China60
Sweden58
Austria58
Netherlands57
Spain56
South Africa54
Switzerland53
Uganda53
Seychelles53
Colombia52
Australia50
Hungary47
Italy46
Hong Kong46
Chile45
Argentina44
Philippines42
Greece40
Portugal40
Brazil37
Cyprus37
South Korea35
United States32
Latvia26
Peru25
Mexico17

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