An update on secular trends in physical fitness of children and adolescents from 1972 to 2015: A systematic review

There is evidence that youth physical fitness (particularly cardiorespiratory endurance) has declined globally overthe past decades. Ever since the first reports on negative trends in physical fitness, efforts were undertaken by forinstance the World Health Organization to promote physical activity and fitness. The objective of this systematic review is to provide an ‘update’ on secular trends in youth physical fitness. A systematic literature search was conducted in the electronic databases PubMed and Web of Science to locate studies that explicitly reportedsecular trends in youth physical fitness. Studies were included if they examined secular trends between at least two time pointsacross a minimum of five years. In addition, they had to document secular trends in cardiorespiratory endurance, relative muscle strength, proxies of muscle power or speed in apparently healthy children and adolescents aged 6-18 years. Scores were standardized (i.e., converted to z-scores) with sample-weighted means and standarddeviations, pooled across sex and year of assessment within cells defined by study, test, and children´s age. Theoriginal search identified 524 hits. In the end, 22 studies met the inclusion criteria. Cardiorespiratory endurance exhibited a large initial increase and an equally large subsequent decrease, but the decrease appears to havereached a floor for all children between 2010 and 2015. Relative muscle strength and speed showed small increaseswhile proxies of muscle power declined. Although the negative trend in cardiorespiratory endurance appears to havereached a floor in recent years, because of its association with markers of health, we recommend further initiatives in PA and fitness promotion for children and adolescents.


Authors: Thea Fühner1, Reinhold Kliegl1, Fabian Arntz1, Susi Kriemler2, Urs Granacher1
1 Division of Training and Movement Sciences, University of Potsdam, Germany
2 Epidemiology, Biostatistics and Prevention Institute, University of Zurich, Switzerland
Supervisor: Prof. Dr. Urs Granacher

Thea Fühner, M.Sc.


Research Associate / PhD Student
Division of Training and Movement Sciences University of Potsdam




Thea Fühner received her Bachelor of Arts in Sports Science and Education at the Department of Sports and Sports Science, University of Osnabrück, Germany and her Master of Science in Sports Science from the Faculty of Sport Science, Ruhr University Bochum, Germany. Since 2019 she works as a research associate and does her PhD in the Division of Training and Movement Sciences, University of Potsdam, Germany. There she coordinates two projects: The EMOTIKON project which deals with the assessment of physical fitness in third graders in the Federal State of Brandenburg and the KINGS Study which is about resistance training in young athletes. Her major research interests are the association between physical fitness and factors such as living area, socioeconomic status, physical activity status, and participation in sport clubs as well as secular trends in physical fitness. Since October 2020, she is a member of the FLV program.