WHO study reveals physical inactivity among adolescents: RPTU researcher provides insights into the German situation
A new analysis of more than 3.2 million adolescents across 140 countries reveals that physical inactivity remains a global challenge. In Germany, only around one in seven adolescents achieves the recommended level of daily physical activity on all seven days of the week. The study also highlights pronounced differences between boys and girls. The statistical modelling underpinning the large-scale international investigation was led by RPTU researcher Seth Flaxman.
One in four adolescents worldwide reported that they had not been physically active for at least 60 minutes on a single day during the week prior to being surveyed. This is one of the key findings of a new study published by the World Health Organization (WHO) in The Lancet Global Health. The international study involved substantial contributions from RPTU University Kaiserslautern-Landau, where Seth Flaxman, Professor of Computer Science, led the statistical modelling of the research.
The analysis is based on 389 population-based surveys from 140 countries and territories, covering more than 3.2 million adolescents aged 11 to 17 years. The aim was to produce updated national, regional and global estimates of adolescent physical activity, assess developments since 2010, and evaluate progress towards the WHO’s global target for 2030.
“Globally and in Germany, too many teens are not active enough. 1 in 4 teens worldwide are not active for even one hour on any day of the week. We know this affects their physical and mental health today and for the rest of their lives. We have the power to change this as a society. We can empower teens to be active every day and create inclusive policies to reach the 1 in 4 who are not active on any day.”
Seth Flaxman is internationally recognised for his work at the intersection of statistics, machine learning and global health. At RPTU, he strengthens research into data-driven approaches to societally relevant challenges and contributes his expertise to the university’s AI, Computing and Society initiative, which explores the societal implications and applications of modern artificial intelligence. His research combines advanced statistical and machine-learning methods with applications in population and global health. He works closely with the WHO, UNICEF and the World Food Programme on data-driven models relating to physical activity, climate-related threats to children's health, and food insecurity.
Complex Data Analysis
For the study, researchers combined data from national health and population surveys. They analysed how many days per week adolescents achieved the WHO recommendation of at least 60 minutes of moderate-to-vigorous physical activity. An “active day” was defined as a day on which this threshold was met. Using advanced statistical models, the researchers were able to estimate patterns of physical activity by age, sex, country and year, and to project future developments through to 2030.
German Adolescents Rarely Meet Physical Activity Recommendations
The findings present a mixed picture for Germany. On the one hand, adolescents in Germany are broadly comparable to many of their European peers in terms of physical activity. On the other hand, the vast majority still fail to meet the WHO recommendations.
Only around one in seven adolescents in Germany is physically active for at least 60 minutes on all seven days of the week. At approximately 15 per cent, Germany is only slightly above the global average of 14 per cent. German adolescents average just under four active days per week.
In international comparison, Germany ranks in the middle of the field. The proportion of adolescents achieving at least 60 minutes of physical activity on all seven days of the week is lower than in Finland (28 per cent), Canada (25 per cent), Poland and Austria (19 per cent each), the Netherlands (18 per cent) and the United Kingdom (17 per cent). Germany's results are comparable to those of Switzerland (15 per cent) and Denmark (14 per cent), while France (11 per cent) and Italy (9 per cent) record lower levels.
The study also shows that nearly half of all adolescents in Germany are only active on a limited number of days: an estimated 45 per cent achieve the recommended amount of physical activity on no more than three days per week. These findings suggest that regular physical activity is not yet an established part of everyday life for many young people.
Boys Are Almost Twice as Likely as Girls to Be Active Every Day
The most striking differences emerge between boys and girls. While 17 per cent of boys are physically active every day, this applies to only 9 per cent of girls. Physical activity also declines markedly with age: 11-year-olds average 4.3 active days per week, whereas among 17-year-olds this figure falls to around 3.4 days.
Lead author Dr Tessa Strain of the University of Edinburgh commented: “In our new study we find that German teens are a little less active than many of their European neighbours, and most teens are simply not active enough. We see stark inequalities in Germany: boys are almost twice as likely as girls to be active every day, and older teens are less active than younger teens.”
At the same time, the study indicates that comparatively few German adolescents go through an entire week without a single active day. While around 25 per cent of adolescents worldwide do not meet the activity recommendation on any day of the week, the corresponding figure in Germany is only around 5 per cent.
Little Progress Over the Past 15 Years
According to the researchers, the global situation has improved little over the past 15 years. Overall activity levels among adolescents have remained largely unchanged. Physical inactivity is widely recognised as a major risk factor for cardiovascular disease, type 2 diabetes and several forms of cancer.
The findings also highlight the scale of the challenge ahead. According to the study’s projections, no country is currently on track to achieve the WHO’s global target for 2030, which calls for a substantial reduction in the proportion of adolescents who fail to achieve the recommended 60 minutes of daily physical activity. The results underscore that adolescent physical inactivity remains a major challenge for public health and society worldwide.
A key conclusion of the WHO is that physical activity is strongly influenced by the environments in which young people live. Whether children and adolescents are sufficiently active depends, among other factors, on safe transport infrastructure, access to public spaces, the school environment, and the availability and affordability of sport and recreational opportunities. At the same time, many young people are spending an increasing share of their leisure time in front of screens.
The researchers therefore stress that encouraging adolescents to be more active is not enough on its own. Equally important is creating environments that make physical activity a natural and accessible part of everyday life.
Publication
National, regional, and global trends in adolescent physical activity from 2010 to 2025: a pooled analysis of 389 surveys with 3.2 million participants from 140 countries. The Lancet Global Health, 2026.