One in four teens has no hour-long activity day in a week

A World Health Organization report estimates that one in four teenagers worldwide had no day in a week with at least 60 minutes of moderate-to-vigorous physical activity in 2025, BR reports. Experts warn that a lack of exercise in childhood can affect health throughout life.

The WHO based its estimates on 389 surveys from 140 countries and territories, covering more than 3.2 million young people. On average, teenagers were active for at least an hour on 2.7 days a week. Only 14 percent reached that level on all seven days. The activity measure includes everyday movement, such as at school, as well as sport. The WHO cites academic pressure, heavy use of digital media and a shortage of sports facilities as possible reasons for inactivity.

At the LMU Klinikum Großhadern, a hospital, senior consultant and orthopaedic surgeon Thomas Niethammer says exercise helps shape joints, muscles, tendons and bones. Children’s joints are initially soft and cartilage-like, he says, and may develop inadequately if they are not used enough.

Bones also benefit from exercise during childhood and adolescence. Niethammer says they become stronger when placed under sufficient strain, reaching their maximum strength at around age 20 to 30 before weakening. He warns that inactivity can contribute to a cycle of weight gain and less movement, raising the risk of obesity. In adulthood, this may be followed by cardiovascular problems, diabetes or osteoarthritis caused by excessive strain on the joints.

Children do not need to take up competitive sport, Niethammer says. The important thing is to make movement part of everyday life and find an activity they enjoy. At SV Waldeck Obermenzing, a football club in Munich’s Obermenzing district, children train several times a week. One player, Leon, says he plays football, basketball and tennis and does sport every day.