Secular Trends in Physical Fitness of Children and Adolescents: A Review of Large-Scale Epidemiological Studies Published after 2006

Abstract

Physical fitness (PF) of children and adolescents is an important resource for their future health. Population-based studies, however, rarely report secular changes of PF, although monitoring of these is crucial to deriving information for adequate interventions. This review aims to report trends in PF of children and adolescents. A literature search was conducted in PubMed in July 2019. Cohort studies published in English allowing statements to be made on trends in PF by comparing youth between the ages of four and 18 years were included. The review identified 24 studies from 16 countries meeting the inclusion criteria, with an overall sample size of more than 860,000 children and adolescents. Through a standardized quality assessment tool, we classified two studies as strong, 21 as moderate, and only one as weak. We analyzed specific secular trends separately for the five different dimensions: endurance, strength, speed, flexibility, and coordination. The majority of studies report a decline of PF over time; however, a few studies report conflicting results. Performance in endurance, strength, and flexibility decreased over time, whereas there was no consistent trend reported for speed and coordination. Overall, there is no international standard on examining and reporting changes or secular trends in PF of children and adolescents, and comparability of studies is limited due to heterogeneous conditions of conducting and analyzing PF tests. Consequently, standardized and consistent international monitoring should be implemented.

Secular trends in health-related physical fitness among 11–14-year-old Croatian children and adolescents from 1999 to 2014

“…The observation of a declining trend of flexibility in this study is consistent to previous studies conducted among similar age groups 12 , 21 , 23 , 32 , 36 , 47 . Flexibility performance is associated to body size (mainly to body-mass index), and since we observed a significant increase of body-mass index from 1999 to 2014, it is possible that such increase would correlate to a negative trend of flexibility 21 .…”

“…Of note, we observed that the level of cardiorespiratory fitness had declined from 1999 to 2014 by ≈ 22.0% for both sexes, which is similar to previous studies using 20-m shuttle run test as a proxy of cardiorespiratory fitness 16 . In general, a recent systematic review aiming to report trends in physical fitness has shown, that the declining trend in cardiorespiratory fitness is more obvious in studies with more time periods or longer follow-ups 36 , which has also been supported by large-scale epidemiological findings 18 .…”

“…Secular trends of physical fitness in children and adolescents have been well-studied in the past decades 10 , 12 – 35 . In general, values in cardiorespiratory, muscular and flexibility fitness decline, and values in body-mass index (as a measure of body size) increase, especially in work that goes back further in time (between 1960 and 1980s), while there have been conflicting findings for motor fitness in terms of a decrease, increase or stagnation 36 . Such inconsistencies may depend on the sample size, age- and sex-specific populations studied, and physical fitness tests applied 12 .…”

Effects of School-Based Exercise and Nutrition Intervention on Body Composition and Physical Fitness in Overweight Adolescent Girls

“…In addition, physical fitness (PF) levels appears to be declining in this population [ 13 , 14 ]. Accordingly, childhood and adolescence is a critical period for the development of PF [ 15 ] and adolescence has been identified as one of the stages that may play a critical role in the development and persistence of obesity and related comorbidities into adulthood [ 16 ]. As the social environment for adolescents diversifies and they become more independent, the key influences on their eating practices begin to change [ 17 ].…”

Chronological and Skeletal Age in Relation to Physical Fitness Performance in Preschool Children

“…Further, a longitudinal study showed a moderate to a highly significant correlation between health-related physical fitness components in childhood and those in adulthood (6). With the growing public health concern worldwide, there is an overall declining trend of physical fitness among children (7). Hence, the improvement and maintenance of physical fitness have become the main challenges for many researchers.…”