An international team of researchers analysed the 20-metre shuttle data, also known as the beep test, of 1.1 million kids aged 9 to 17 from 50 countries around the world.
The beep test is a standardised and commonly used field-based test of aerobic fitness levels of children and youth.
“If all the kids in the world were to line up for a race, the average Danish child would finish at the front of the pack, placed 6th out of 50,” said Grant Tomkinson, an associate professor of kinesiology at the UND College of Education & Human Development and senior author of the study.
“Kids who are aerobically fit tend to be healthy, and kids who are healthy are apt to be healthy adults. So studying aerobic fitness in the early years is very insightful to overall population health.”
Tanzania, Iceland, Estonia, Norway and Japan make up the top five in the rankings, while Mexico placed last.
The study also found that income inequality – the gap between rich and poor – is strongly correlated with aerobic fitness, suggesting that kids from countries with smaller income inequality have better fitness.