The Effects of a Multicomponent Social Support Intervention on Physical Fitness and Exercise Attitude in Children: A 12-Week Randomized Controlled Trial.

Purpose: The current study is intended to assess the effects of a multicomponent social support intervention program on grip strength, sprinting, jumping, agility, flexibility, core strength and exercise attitude among children over a period of twelve weeks. Method: This study followed a randomized parallel design in which 366 children (age: 9.35 ± 1.12 years) in the 3rd−5th grade at an elementary school in China were allocated to an intervention group (n = 183) or a control group (n = 183). Participants were assessed twice (baseline and postintervention) for the following tests: (i) grip strength, (ii) 50 m dash, (iii) rope skipping, (iv) sit-ups, (v) sit-and-reach, and (vi) exercise attitude. The intervention group received the "Exercise Methods and Wellness Knowledge Guide (EMWKG)" leaflet three times a week. The control group was not required to make any changes. Results: Significant increases in pre−post left-hand grip strength (Cohen's d = 0.10, p < 0.001), right-hand grip strength (Cohen's d = 0.09, p < 0.001), and behavioral intention (Cohen's d = 0.17, p < 0.01) were observed in the intervention group. Students in the control group showed significant decreases in three indicators: both 50 m (Cohen's d = 0.19, p < 0.01) and sit-ups (Cohen's d = 0.14, p < 0.05) as well as sit-and-reach (Cohen's d = 0.46, p < 0.001). Significant differences (p < 0.001) were found between the two groups in right-hand grip strength (F = 7.109, ηp2 = 0.020), sit-and-reach (F = 11.255, ηp2 = 0.031), and subjective standards (F = 15.461, ηp2 = 0.043). A comparison of the post hoc test results showed that the intervention group scored 0.519 kg (95% CI: 0.136−0.901, Cohen's d = 0.27), 0.944 cm (95% CI: 0.0391−1.497, Cohen's d = 0.35), and 2.535 points (95% CI: 1.267−3.803, Cohen's d = 0.41) higher than the control group in right-hand grip strength, sit-and-reach, and subjective standards, respectively. Conclusion: This combined social support theory-based intervention was effective in improving exercise attitude and fitness among children in 12 weeks.

Effects of a SMART Goal Setting and 12-Week Core Strength Training Intervention on Physical Fitness and Exercise Attitudes in Adolescents: A Randomized Controlled Trial.

This study aimed to analyze the impacts of a 12-week core strength training (CST) and goal-setting (GS) program on the core endurance, agility, sprinting, jumping, grip strength, and exercise attitude in a group of adolescents. This study followed a randomized parallel design in which 362 adolescents (age: 14.5 ± 1.07 years; body mass index: 19.82 ± 3.64) were allocated to a GS (n = 89), CST (n = 92), or GS + CST (n = 90) program or to a control group (n = 91). Participants were assessed two times (baseline and postintervention) for the following tests: (i) 50 m dash, (ii) grip strength, (iii) long jump, (iv) 1000 m running for boys and 800 m for girls, (v) core endurance, and (vi) exercise attitude. Significant differences (p < 0.05, η2p = 0.035−0.218) were found between the four groups of the six components of physical fitness and the three components of attitude toward exercise (target attitudes, behavioral habits, and sense of behavioral control). Between-group analysis revealed that the GS + CST had significant advantages (p < 0.05) over the CON in terms of the 50 m dash (Cohen's d = 0.06), grip strength (Cohen's d = 0.19_left, 0.31_right), 800/1000 m running (Cohen's d = 0.41), core endurance (Cohen's d = 0.95), and sense of behavioral control (Cohen's d = 0.35). Between-group analysis also revealed that the CST had significant advantages over the CON in terms of grip strength (Cohen's d = 0.27_left, 0.39_right), 50 m (Cohen's d = 0.04), long jump (Cohen's d = 0.21), 800/1000 m (Cohen's d = 0.09), and core stability (Cohen's d = 0.63), which were significantly different from CON (p < 0.05). GS differed from CON only on 50 m (Cohen's d = 0.02) and core stability (Cohen's d = 0.13) with a small effect (p < 0.05). We conclude that the combined intervention of GS and CST is more effective in promoting fitness in adolescents, i.e., GS + CST > CST and GS + CST > GS.

Longitudinal Association of Economic Growth with Lung Function of Chinese Children and Adolescents over 30 Years: Evidence from Seven Successive National Surveys.

(1) Background: Recent studies reported that decrease in lung function of Chinese children and adolescents continues to decline, although the change has been insignificant and has reached a plateau. However, studies have not explored the relationship between lung function and economic development in China. This study sought to explore the longitudinal association between socio-economic indicators and lung function; (2) Method: Data were obtained from seven successive national surveys conducted by the Chinese National Survey on Students' Constitution and Health from 1985 to 2014. Lung function of school-age children (7-22 years) was determined using forced vital capacity (FVC). GDP per capita and urbanization ratio were used as economic indicators. A fixed-effects model was employed to examine the longitudinal association after adjusting for height, weight, and time trends; (3) Results: Socio-economic indicators showed a U-curve relationship with lung function of boys and girls from urban and rural areas. Lung function initially decreased with GDP per capita or urbanization ratio and reached a minimum. Lung function then increased with increase in GDP per capita or urbanization ratio. The findings indicate that the relationship between economic growth and lung function is different in different development stages. In less-developed provinces, economic growth was negatively correlated with lung function, whereas, in developed provinces, economic growth was positively correlated with lung function; (4) Conclusion: The findings of the current study show that economic growth has significantly different effects on lung function at different economic levels. Therefore, governments should improve lung health in children and adolescents from low and middle economic regions.

Economic Growth and Weight of Children and Adolescents in Urban Areas: A Panel Data Analysis on Twenty-Seven Provinces in China, 1985-2014.

Background: With the rapid economy development of China, the overweight and obesity rates of school-age children and adolescents in China have been on the rise. The purpose of this study is to explore how powerful an influence economic growth has on the weight of children and adolescents and examine the relationship between China's macroeconomic development and weight of children and adolescents in the past 30 years using provincial panel data collected from more than 1 million children and adolescents. Methods: Panel data from seven longitudinal surveys (1985, 1991, 1995, 2000, 2005, 2010, and 2014) of the Chinese National Surveys on Students' Constitution and Health, which include students, ages 7-22 years, from 27 provinces, were analyzed. Fixed-effects models were used to estimate the associations. Results: (1) For every 1% increase in per capita disposable income, the average weight of male and female students increased by ∼0.035% (p < 0.01) and 0.039% (p < 0.01), respectively. (2) Linear relationships were found between economic growth and weight of both boys and girls during the 30 years of the survey. The positive effect of the Chinese economy on weight of children and adolescents has been gradually increasing persistently. Conclusion: Linear relationships exist between economic growth and weight status of children and adolescents. The significant positive effect of the Chinese economy on weight of children and adolescents has been gradually and persistently increasing.

Economic Growth and Cardiorespiratory Fitness of Children and Adolescents in Urban Areas: A Panel Data Analysis of 27 Provinces in China, 1985-2014.

With rapid economic development in China, cardiorespiratory fitness (CRF) of children and adolescents is on a decline. However, this appears to have slowed down, reaching stagnation in certain areas. However, it is unclear if the change in CRF is related to economic growth and development or not. This study describes trends in CRF of Chinese children and adolescents, and empirically tests the relationships between China's macro-economic developments and cardiorespiratory fitness of children and adolescents over the past 30 years using provincial panel data collected from one million samples. We used per capita disposable income as the economic indicator. CRF was assessed by using running tests: 50 m × 8 for boys and girls (7-12 years), 1000 m for boys (13-22 years), and 800 m for girls (13-22 years). The results show that economic growth has a U-shaped relationship with CRF of children and adolescents (both boys and girls). It appears that as incomes increased, CRF of urban male and female students in China gradually decreased to its lowest point, after which it showed an upward trend. From a horizontal perspective, it can be inferred that for low-developed provinces, increases in incomes cause a decrease in CRF levels. In contrast, for highly developed provinces, as incomes increase, CRF levels increase. This study provides the first empirical evidence of the relationship between macro-economy and CRF of youth, based on provincial panel data. The results presented here can be used to formulate health policies targeting the cardiorespiratory fitness of children and adolescents from middle-income provinces in China. This study also provides a reference for developing countries.