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

Temporal trends and distributional changes in cardiorespiratory fitness among Chinese children and adolescents from 1985 to 2019

OBJECTIVES

The aim of this study was to analyze the temporal trends in cardiorespiratory fitness (CRF) and body mass index (BMI) among children and adolescents from 1985 to 2019.

METHODS

A total of 1 840 212 children and adolescents aged 7-18 years (921 223 boys) were tested for CRF from 1985 to 2019. CRF was tested by 50-m × 8 shuttle run for boys and girls aged 7-12 years, 1000-m run for boys aged 13-18 years, and 800-m run for girls aged 13-18 years. Trends in BMI from 2000 to 2019 were also investigated.

RESULTS

Cardiorespiratory fitness decreased during the entire 34 years among children and adolescents in all sex and age categories, and the most rapid decline occurred from 1995 to 2005. Some positive trends in CRF were observed among adolescents aged 13-15 years from 2005 to 2019 and among girls aged 16-18 years from 2014 to 2019. The variation in the CRF distribution was not uniform, with Z-scores for participants with high CRF levels changing little or increasing (CRF stabilized or improved) and Z-scores for participants with low CRF levels continuing to decrease (CRF decreased). BMI increased over time for boys and girls in all age categories, with an acceleration of the increase for adolescents in recent years.

CONCLUSIONS

This study revealed that the overall CRF levels of Chinese children and adolescents decreased over three decades but stabilized or improved in recent years. BMI continued to increase. Our findings are important for the focus on future domestic physical fitness and public health.

Secular trends in skill-related physical fitness among Slovenian children and adolescents from 1983 to 2014

It is vital from the public health and educational perspective to be familiar with changes in the fitness levels of individuals and populations since fitness is associated with several health outcomes and cognition. Skill-related physical fitness refers to performance in sports or occupation and is associated with motor skill performance. The aim of the present study was to examine secular trends in skill-related physical fitness of 16 678 participants in four youth generations of Slovenian children and adolescents in years 1983 (n = 3128), 1993/94 (n = 3413), 2003/04 (n = 5497), and 2013/14 (n = 4640). Using repeated cross-sectional design, we observed fitness level of all participants divided into three age groups: 6-10, 11-14, and 15-19 years. Skill-related physical performance was measured with seven fitness tests for speed, coordination, balance, and flexibility. Analysis of covariance was used to compare differences in fitness performance between decades in each age and sex group, adjusted for body height, body weight, and body mass index. Overall, large but inconsistent changes in coordination, a small improvement in speed, and a decline in flexibility were seen. The trends over the whole examined period were not linear throughout decades. Generally, positive trends were noticed in periods 1983-1993 (range 1.4%-17.9%; except flexibility) and 2003/04-2013/14 (range 0.2%-36.4%; except age group 15-19 years) while in the period 1993/94-2003/04 there are some particularities in secular trends according to individual components as well as age groups. In general, the secular trend showed a positive direction for both genders (p < 0.05), except for gross motor coordination, which demonstrated positive trends in 1993 and 2013 compared with a decade earlier (p < 0.05) and from 1983 to 2013/14, except for the youngest boys in 2003 and the youngest girls from 1993 to 2003 (p < 0.05). Our findings call for exercise programs aimed at improving speed and gross motor coordination in both sexes and all age groups, especially in the group of 15-19 years old.

Challenges of social change: The 2021 Republic of Slovenia report card on physical activity of children and adolescents

Background

Slovenian children are facing considerable health challenges from the rapid social changes that influence their opportunity to engage in daily physical activity.

Objective

To overlay the social changes to the established Report Card model as a means of contextualising the extreme changes in physical activity and fitness observed over several years.

Methods

Benchmarks were graded for 10 core indicators, plus two (Sleep, Seasonal Variations). Active Healthy Kids Slovenia members met (predominantly via zoom) liaising with team leader(s) on a flexible, individual basis, based on coronavirus disease 2019 (COVID-19) regulations, over the ∼2-year assessment period of the project. Data were separated to the years prior to, 'pre' 2018-2020, and 'during' the global pandemic (2020-2021). Where sufficient data existed for both timeframes, grades were averaged to produce an overall grade.

Results

Grade results are expressed as pre/during/final grade, where the final grade (bolded) is a straight average of the two preceding time epochs: Overall Physical Activity (A-/A-/A-), Organized Sport and Physical Activity (C+/C/C), Active Play (D/C+/C), Active Transport (C/INC/C), Sedentary Behaviour (B/C/C+), Physical Fitness (A+/A-/A), Family and Peers (B+/INC/B+), Schools (A/A/A), Community and Environment (A+/A+/A+), Government (A/F/D), Sleep (D-/INC/D-), Seasonal Variations (D/C-/D+).

Conclusion

Although Slovenia has some of the most consistently physically-active children in the world, the effects of the COVID-19 pandemic exerted significant reductions in physical activity opportunities, and especially when coupled with funding re-distributions, resulted in the steepest decline of child physical fitness observed within the >35-year history of Slovenia's well-established national fitness surveillance system.

Secular trends in physical fitness of rural Chinese children and adolescents aged 7-18 years from 1985 to 2019

The main purpose of the study was to evaluate the secular trends in physical fitness of Chinese rural children and adolescents aged 7-18 from 1985 to 2019. The speed, muscular strength, explosive power fitness, cardiorespiratory fitness, and flexibility were investigated by National Survey on Students' Constitution and Health in 1985, 2000, 2010 and 2019. During the period 1985-2000, the physical fitness of Chinese rural children and adolescents improved except for flexibility, and almost all of them reached the maximum increase rate. During the period 2000-2010, in addition to the improvement of flexibility, other fitness showed downward trends, and the decline ranges were large. During the period 2010-2019, the speed of boys rebounded, flexibility, explosive power and muscular strength continued to decrease. Meanwhile, speed, flexibility and muscular strength in girls rebounded, and the explosive power continued to decline. From 2000 to 2019, the body mass index increase accelerated. This study shows that some components of physical fitness of Chinese rural children and adolescents have shown positive trends in recent years, especially for girls and adolescents aged 13-15 years. However, it may also imply inequality between sexes and ages, which provides a reference for the focus of the country's physical fitness and health monitoring and intervention measures.

Top 10 International Priorities for Physical Fitness Research and Surveillance Among Children and Adolescents: A Twin-Panel Delphi Study

BACKGROUND

The measurement of physical fitness has a history that dates back nearly 200 years. Recently, there has been an increase in international research and surveillance on physical fitness creating a need for setting international priorities that could help guide future efforts.

OBJECTIVE

This study aimed to produce a list of the top 10 international priorities for research and surveillance on physical fitness among children and adolescents.

METHODS

Using a twin-panel Delphi method, two independent panels consisting of 46 international experts were identified (panel 1 = 28, panel 2 = 18). The panel participants were asked to list up to five priorities for research or surveillance (round 1), and then rated the items from their own panel on a 5-point Likert scale of importance (round 2). In round 3, experts were asked to rate the priorities identified by the other panel.

RESULTS

There was strong between-panel agreement (panel 1: r_s = 0.76, p < 0.01; panel 2: r_s = 0.77, p < 0.01) in the priorities identified. The list of the final top 10 priorities included (i) "conduct longitudinal studies to assess changes in fitness and associations with health". This was followed by (ii) "use fitness surveillance to inform decision making", and (iii) "implement regular and consistent international/national fitness surveys using common measures".

CONCLUSIONS

The priorities identified in this study provide guidance for future international collaborations and research efforts on the physical fitness of children and adolescents over the next decade and beyond.

Moving in a hotter world: Maintaining adequate childhood fitness as a climate change countermeasure

Children cope with high temperatures differently than adults do, largely because of slight alterations in their body proportions and heat loss mechanisms compared to fully mature humans. Paradoxically, all current tools of assessing thermal strain have been developed on adults. As the Earth's warming continues to accelerate, children are set to bear the health risk brunt of rising global temperatures. Physical fitness has a direct impact on heat tolerance, yet children are less fit and more obese than ever before. Longitudinal research reveals that children have 30% lower aerobic fitness than their parents did at the same age; this deficit is greater than can be recovered by training alone. So, as the planet's climate and weather patterns become more extreme, children may become less capable of tolerating it. This comprehensive review provides an outline of child thermoregulation and assessment of thermal strain, before moving to summarize how aerobic fitness can modulate hyperthermia, heat tolerance, and behavioral thermoregulation in this under-researched population. The nature of child physical activity, physical fitness, and one's physical literacy journey as an interconnected paradigm for promoting climate change resilience is explored. Finally, future research foci are suggested to encourage continued exploration of this dynamic field, notable since more extreme, multifactorial environmental stressors are expected to continue challenging the physiological strain of the human population for the foreseeable future.

Can Primary School Mathematics Performance Be Predicted by Longitudinal Changes in Physical Fitness and Activity Indicators?

Objective

To determine to what extent physical fitness indicators and/or moderate to vigorous physical activity (MVPA) may account for final mathematics academic performance (AP_math) awarded at the end of primary school.

Methods

School-aged youth were sampled in a repeated-measures, longitudinal design in Grade 6 (∼11 years), and again in Grade 9 (∼14 years). The youth (N = 231, 111 girls) completed a fitness test battery consisting of: flamingo balance test, standing long jump, backward obstacle course, plate tapping, sit ups, sit and reach, handgrip, and 20-m shuttle run. AP_math scores were obtained for all children at the end of Grade 5, end of Grade 8, and end of Grade 9 (their final year of primary school). In a sub-sample of Grade 6 youth (N = 50, 29 girls), MVPA was measured objectively via SenseWear Pro Armbands (MVPA_OB) for seven consecutive days, with measurements repeated in Grade 9.

Results

Math scores decreased from Grade 6 to 9 for both boys and girls (95%CI: −0.89 to −0.53, p < 0.001). MVPA_OB was reduced by ∼45.7 min (−33%) from Grade 6 to 9 (p < 0.01). Significant main and interaction effects are noted for each fitness indicator (p < 0.05). A backward stepwise multiple regression analysis determined significant shared variance in final AP_math grade to the change scores from Grade 6 to Grade 9 in: ΔAP_math, Δbackward obstacle course, Δsit and reach, and Δsit-ups [R² = 0.494, F(4,180) = 43.67, p < 0.0001]. A second regression was performed only for the youth who completed MVPA_OB measurements. In this sub-sample, MVPA_OB did not significantly contribute to the model.

Conclusion

Longitudinal changes in youth fitness and their delta change in AP_math score accounted for 49.4% of the variance in the final math grade awarded at the end of Grade 9. Aerobic power, upper body strength, and muscular endurance share more common variance to final math grade in boys, whereas whole-body coordination was the more relevant index in girls; this finding suggests that future research exploring the relationship of AP and PF should not be limited to cardiorespiratory fitness, instead encompassing muscular and neuro-muscular components of PF.

Do Fitter Children Better Assess Their Physical Activity with Questionnaire Than Less Fit Children?

Most physical activity (PA) questionnaires assess moderate to vigorous PA (MVPA) describing the physical exertion of individuals that might be influenced by their physical fitness. Therefore, the aim of this study was to determine whether fitter children could better assess their PA with the questionnaire than less fit children. The cross-sectional validation study was conducted with 108 children (60 girls) aged 11 to 14 years, who were divided into three fitness groups based on the results of the 600 m running test. To answer the research question, the agreement between their assessment of PA using the SHAPES questionnaire and the UKK RM42 accelerometer data was analysed. One quarter of the participants achieved at least 60 min of MVPA each day, measured by accelerometer. The average MVPA obtained was 97.8 ± 35.6 min per day, with the high fitness group having a significantly higher value compared with the other groups. Moderate to high validity coefficients were found in the high fitness group (Spearman’s ρ range 0.34–0.70). In contrast, the lower fitness groups had poor to moderate validity for all variables (Spearman’s ρ range 0.03–0.42). These results suggest that the fittest children self-assess their PA with the questionnaire better than less fit children, which may advance new directions for the development and evaluation of PA questionnaires and their usability.

The Effect of Pandemic Movement Restriction Policies on Children's Physical Fitness, Activity, Screen Time, and Sleep

Background: The negative impact of isolation, confinement, and physical (in)activity due to pandemic movement restriction has been well-documented over the past year, but less is known on the impact of these policies on children's physical fitness. This study was designed to determine the effects of pandemic movement restriction policies on the 24-hour movement behavior (24-HMB) of children, and whether any alterations are reflected in worsening physical fitness outcomes determined via direct testing. Methods: A two-phase, repeated-measures study with matched controls was conducted. Phase One: N = 62 schoolchildren (N = 31 female) completed self-assessment questionnaires on 24-HMB in October 2018 (pre-pandemic) and again in April 2020, at the height of movement restrictions enacted in response to the COVID-19 pandemic first wave. Phase Two: physical fitness of the original N = 62 children were determined directly pre- and post-isolation using an eight-component standardized fitness test battery and compared to N = 62 control children who were matched for age, sex, school region, and fitness centile scores. Results: During lockdown (total duration: 63 days), moderate-to-vigorous physical activity (MVPA) decreased by ~46 min per day, screen time demonstrated a significant interaction effect, such that kids reported spending less recreational screen time on weekends during lockdown compared to no restriction, and sleep duration was consistently lower (95% CI: -104.1 to -45.5 min, p < 0.001). No interaction effect was present for direct fitness indicators, including: hand tapping (reaction time), standing broad jump, polygon backward obstacle course (coordination), sit-ups, stand-and-reach, bent-arm hang, 60-m, and 600-m run (p ≥ 0.05) although significant main effects are noted for both sexes. Conclusion: Initial changes in 24-HMB did not translate to reductions in physical fitness per se, likely due to the high initial fitness levels of the children. Further work is needed to confirm whether longer or repeated movement restrictions exacerbate initial negative 24-HMB trends, especially for children who are less fit when restrictions are initiated, prolonged, or repeated.