Physical fitness trends in a nationally representative sample of Portuguese youth: What has changed from 2008 to 2018?

Population-based trends and distributional characteristics in sit-ups performance among school-aged girls in urban China over three decades

This paper aims to assess population-based trends and distributional characteristics in the sit-ups performance, body height, body mass and body mass index (BMI) among school-aged girls in urban China from 1985 to 2019. Height, mass, BMI and sit-ups performance data for Han Chinese urban girls aged 7-18 years were obtained from the Chinese National Surveillance on Students' Constitution and Health surveys from 1985 to 2019. Population-based trends were estimated by a post-stratification population weighting procedure. There was a moderate improvement in sit-ups performance from 1985 to 2019, increasing by 25.7% or 0.69 effect size (ES). Girls aged 10-12 years experienced the smallest improvement (0.46 ES) and girls aged 16-18 years experienced the largest improvement (0.88 ES). Improvements in sit-ups performance were the major trend across periods, but there was a negligible improvement in the 1990s (0.04 ES) and a small decrease in the 2000s (-0.36 ES), while height, mass and BMI (from 2000 to 2019) continued to increase from 1985 to 2019. The distribution of the change in sit-ups performance was uneven, the improvements were somewhat greater at both ends of the distribution.The government should implement differentiated health promotion programs, especially for those with greater health risks.

Improving Physical Activity, Athletic Performance, and School Climate in Disadvantaged Schools

BACKGROUND

Children are encouraged to spend 60 min each day performing moderate-to-vigorous physical activity. In this study, we assessed the impact of an intervention throughout the school year on physical activity, sports performance, and school climate in fifth-sixth-grade children from schools in a disadvantaged neighborhood.

METHODS

The intervention group (n = 44) participated in six weekly 45 min physical education classes; an athletic subgroup of these students participated in two additional weekly athletic classes. The control group (n = 73) participated in two standard weekly physical education classes. Pre- and post-intervention Eurofit Physical Fitness Tests were conducted.

RESULTS

Significant improvements were seen in the stand-and-reach test among girls in the intervention group [M = -0.47(7.71)-1.26(8.02) cm] compared to the control group [F(1,54) = 14.86, p < 0.01, η2 = 0.22]. No differences were seen between the groups in their daily physical activity, screen time, or school climate (p = 0.13, p = 0.17, and p = 0.35, respectively). Improvements were seen in the shuttle-run beep test, yet only in the athletic subgroup [F(1,93) = 60.38, p < 0.001, η2 = 0.39]. A trend towards significance for the largest improvement was seen in the athletic subgroup, who participated in eight weekly physical activity classes [F(2,93) = 3.75, p = 0.027, η2 = 0.07).

CONCLUSIONS

Physical education curricula should enhance their focus on athletic performance, while increasing the number of weekly physical education classes in schools, to include daily lessons throughout the school week, each lasting at least 45 min.

Cardiorespiratory fitness and muscular fitness correlates in youth: A hierarchy of behavioral, contextual, and health-related outcomes

OBJECTIVES

Despite the health importance of identifying correlates of physical fitness in youth, no investigation to date has explored the influence of behavioral, health-related, and contextual correlates simultaneously. We investigated the hierarchical relationship of multiple modifiable correlates favoring or diminishing cardiorespiratory and muscular fitness in youth.

DESIGN

Cross-sectional investigation.

METHODS

In a sample of 5174 children and adolescents, 31 correlates were hierarchized according to their impact on cardiorespiratory and muscular fitness assessed using the FITESCOLA® fitness battery. A Chi-squared Automatic Interaction Detection approach was employed and measures of correlation and association were used to investigate the relationship between physical fitness and correlates.

RESULTS

In children, body mass index was the most relevant factor to discriminate between high and low cardiorespiratory and muscular fitness of the upper, middle, and lower body. While body mass index was more important than any other correlate to differentiate levels of upper and lower body muscular fitness during adolescence, specific characteristics of sports participation emerged as key factors to discriminate between high and low cardiorespiratory fitness and middle body muscular fitness. Other correlates, including the self-report of active recess time, active commuting to school, favorable neighborhood conditions, and limited time on screens and cellphones, were demonstrative of favorable physical fitness levels.

CONCLUSIONS

Both body composition and sports-related characteristics emerged as the two most relevant factors of physical fitness in youth. Additional health benefits may be obtained from building supportive environments for sports and healthy exercise habits within the household and at different school education levels.

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.