Secular Trends of Physical Fitness in Twenty-Five Birth Cohorts of Slovenian Children: A Population-Based Study

Abstract

In Slovenia, the national SLOfit surveillance system of the somatic and motor development of children and youth has been enabling researchers to observe the developmental trends of the entire population of school-aged children since 1987. The national database currently incorporates over 7.2 million sets of measurements of eight fitness tests and three anthropometric measurements. Since 1991, as in the rest of the world, in Slovenia, there is a common perception that the physical fitness of contemporary children is in decline and below the level of the physical fitness of the previous generation's childhood fitness. Our paper examines the trends of physical fitness in 26 birth cohorts of 7-10-year-olds. The analysis shows that the secular trends of physical fitness in boys and especially in girls have been positive and that the level of physical fitness of recent birth cohorts exceeds the national average of physical fitness of the 1989-2019 period. At the same time, the analysis reveals that the distribution of physical fitness has been changing from almost normal in the cohorts born in the first half of the 1980s, toward positively skewed in the subsequent cohorts born before the year 2000, and bimodal distribution in the later cohorts, indicating growing inequality and polarization of the motor development of children.

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

“…A great majority of adolescents do not meet the recommendations for moderate-to-vigorous PA (MVPA) [ 6 ] despite well-documented positive impact on skeletal [ 7 , 8 ], metabolic [ 9 , 10 ], cardiovascular [ 11 ], and psychosocial [ 12 ] health. 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 ].…”

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

“…Despite the fact that risk factors for diseases usually manifest during adulthood, studies have shown that childhood and adolescence are critical time-points for maintaining ‘good’ lifestyle habits and develop high physical fitness levels 9 due to well-tracking characteristics of physical fitness from childhood to adulthood 1 . However, a common perception has been embraced that the physical fitness in youth has declined because of more time spent in sedentary behavior, lack of physical activity and consuming fat-rich food 10 . Such decrease is, however not uniform in different countries and physical fitness modalities 11 , 12 .…”

“…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 .…”

“…In recent years, several European countries have proposed national monitoring systems for screening and monitoring biological development of children and adolescents 10 , 37 – 39 . Although such measures through projects (like the HBSC study) have been implemented and tested in Croatian youth, the most recent study has shown that ≈ 50% of youth in Croatia do not meet the recommended levels of physical activity, ≈ 25% exceed 2 h of screen time per day and have high blood pressure, and ≈ 20% have excess weight, leading to overweight and obesity status 40 .…”

Assessment of Secular Trends and Health Risk in Pediatric Cardiorespiratory Fitness From the Republic of Slovenia

“…There is continued debate on the best, or rather, most accurate model to assess 20mSRT as a predictor of CRF (Welsman and Armstrong, 2019). Knowing these limitations, it remains that initial decreases in CRF were reversed from 2003 to 2013 (∼8.2%), across all ages, in both sexes and inline with overall secular trends of physical fitness in Slovenia during that time (Potočnik et al, 2020). Indeed, CRF increased ∼5.4% across the 20-year (1993-2013) period of study.…”