Children’s physical fitness is improving, but they are still not as fit as their parents

Physical fitness is vital for success in sports and athletics, but it is also vital for good healthIf you’re generally fit, you probably have powerful hearts, brains, muscles, and bones, which helps you exercise and increases your chances of living a long, fit, and robust life.

The most vital type of physical fitness for good health is aerobicswhich refers to your ability to exercise or be physically dynamic at a steady pace for an extended period of time (e.g. more than 20 minutes), such as running, walking, cycling, swimming, rowing or playing aerobic sports such as football or basketball.

Monitoring national and international trends in children’s aerobic fitness is vital to understand trends in the underlying current and potential future health of the population. Research shows that if you are in good aerobic shape as an adult, you are less likely to develop or die from chronic diseases such as heart disease, stroke AND some cancers. And if you were able-bodied as a child, you are more likely to be healthy and fit as an adult.

Take a moment to think about your fitness level. Do you think you were as fit as today’s kids when you were their age?

This has been a topic of much debate in recent decades. Most people say that the condition of children has declined, some say that it has not changed at all, while few are willing to say that it has improved.

To facilitate resolve this debate, our research team has spent the last two decades collecting historical fitness data from millions of children around the world.

Improvement in some children

We systematically analysed decades of data from hundreds of studies conducted in many different countries to compare the aerobic capacity of children of the same age and sex, measured using the same fitness tests.

In 2003, our research was the first to conclusively demonstrate that children’s aerobic fitness actually declined worldwide in the slow 20th century. our very large study In a study of 25 million children aged 6 to 19 from 27 countries, we showed that aerobic fitness declined worldwide between 1970 and 2000, with children in 2000 being about 15 per cent less fit than their parents when they were children.

However, there is some good news that suggests that children’s fitness levels may no longer be withering. We recently published update to our 2003 study published in the British Journal of Sports Medicine, which examined trends in the aerobic fitness levels of 1 million children aged 9 to 17 years from 19 high-income (such as Australia, Canada, the United States, etc.) and upper-middle-income (such as Brazil and South Africa) countries between 1981 and 2014. We measured aerobic fitness using the 20-meter shuttle run, also known as the “beep” test or PACER test.

The beep test is the world’s most popular aerobic fitness test for children. It is a progressive exercise test that involves running continuously between two lines 20 meters (66 feet) apart to the rhythm of recorded beeps. The time between the beeps gradually shortens, and the test ends when you can no longer run 20 meters before the beep.

Our updated study confirmed that children’s aerobic fitness levels did indeed decline in the 1980s and 1990s, but interestingly, this decline appears to have slowed since 2000, with fitness levels plateauing over the past decade.

While trends in fitness have varied across countries, most have shown an overall decline. However, after 2000, aerobic fitness improved in Brazil and Japan; reached a plateau in Australia, Canada, Greece, South Africa, and Spain; and declined in Portugal, the United Kingdom, and the United States. Today’s children are still less fit than their parents were when they were children, but the difference is half as gigantic as previously thought—now at about 7 percent.

What’s the cause?

We analysed the links between trends in aerobic fitness and trends in broad socioeconomic and health factors in each country, including income inequality, physical activity levels, and levels of overweight and obesity.

The strongest indicator of a country’s level of well-being was the gap between affluent and impoverished, as measured by the index Gini indexCountries with a widening gap between affluent and impoverished saw the greatest declines in aerobic capacity between 2000 and 2014.

Countries where the gap between affluent and impoverished is widening tend to have more impoverished people. Poverty is associated with impoverished social and health outcomes in high- and upper-middle-income countries, known as the social determinants of health. An indirect effect of poverty can be a lack of opportunities, time, and resources to be physically dynamic and participate in activities that improve or maintain a person’s aerobic fitness level.

Assuming that this relationship is causal, policies to address income inequality and harnessing the potential to improve the social determinants of health in individual countries could lead to improved levels of aerobic fitness, which would not only halt the decline in physical fitness but also reverse this trend for the better for people of all ages.