Purpose: Using 2012 National Health and Nutrition Examination Survey (NHANES) National Youth Fitness Survey data, the authors conducted a cross-sectional secondary analysis to examine the associations of movement behaviors (ie, physical activity [PA] and screen-based sedentary behaviors) and fundamental motor skills (FMS) with fitness (ie, muscular fitness) and fatness (ie, body mass index and waist circumference) in 3- to 5-year-old children. The effect of ethnicity (Hispanic vs non-Hispanic) on these associations was also examined. Methods: A total of 352 children (173 girls; mean age = 4.02 y) from the 2012 NHANES data set were included. Parents reported their child’s PA and screen-based sedentary behaviors. FMS (ie, locomotor and object control) were assessed with the Test of Gross Motor Development, 2nd edition. Other variables used were body mass index, waist circumference, and plank. Results: Hispanic children demonstrated lower levels of PA than non-Hispanic children (P < .05). Children’s FMS emerged as significant predictors of muscular fitness and waist circumference, but not for body mass index in the Hispanic group. In the non-Hispanic group, FMS (ie, object control skills) and PA accounted for significant variances of muscular fitness and waist circumference, respectively. Conclusion: The associations of movement behaviors and FMS with fitness and fatness are different between Hispanic and non-Hispanic young children. Changes in policy or early childhood curriculum may be tailed to promote FMS for an impact on fitness and fatness in both Hispanic and non-Hispanic children.
Xiaoxia Zhang, Xiangli Gu, Tao Zhang, Priscila Caçola and Jing Wang
Phillip Ward, Fatih Dervent, Yun Soo Lee, Bomna Ko, Insook Kim and Wang Tao
This study reports on our efforts toward extending the conceptual understanding of content development in physical education by validating content maps as a measurement tool, examining new categories of instructional tasks to describe content development and validating formulae that can be used to evaluate depth of content development.
The reliability, content, and concurrent validity of content maps and formulae were evaluated together with an application of the content maps and formulae. Descriptive statistics were used to report the data.
The reliability and validity of content maps was established. The new categories allowed for a finer analysis of content development. All formulae differentiated among different content expertise.
If depth of content knowledge is evidenced by tasks designed to refine, extend and apply student performance, then the content map, categories and formulae reported in this study provide tools that have utility for teachers, teacher educators and researchers.
Ying Sun, Jing An, Xi Wang, Ping Zu and Fang-Biao Tao
The study aims to understand the possible gender difference in the associations between physical activity and depressive symptoms during pubertal transition.
Participants were 30,399 children and adolescents of Han ethnicity from urban and rural areas in 8 cities in China. Physical activity (PA) and depressive symptom was assessed by adapted Youth Risk Behavior Survey and Children Depression Inventory (CDI), respectively. Pubertal development was assessed by trained physicians.
In China, over 30% boys and 40% girls reported having no vigorous PA (VPA) or moderate PA (MPA) in the past week. In girls, participating in VPA 1 to 2 days/week showed protective effect for depressive symptoms; whereas in boys, participating in MPA 1 to 2 days/week showed protective effect for depressive symptoms at and after genital stage III (G3).
Moderate frequency (1 to 2 days/week) in PA undertaken might be encouraged to prevent depressive symptoms among adolescents.
Yu-Qian Liu, Yan-Zhong Chang, Bin Zhao, Hai-Tao Wang and Xiang-Lin Duan
Some athletes are diagnosed as suffering from sports anemia because of iron deficiency, but the regulatory mechanism remains poorly understood. It is reported that hepcidin may provide a way to illuminate the regulatory mechanism of exercise-associated anemia. Here the authors investigate the hepcidin-involved iron absorption in exercise-associated anemia. Twelve male Wistar rats (300 ± 10 g) were randomly divided into 2 groups, 6 in a control group (CG) and 6 in an exercise group (EG, 5 wk treadmill exercise of different intensities with progressive loading). Serum samples were analyzed for circulating levels of IL-6 by means of enzyme-linked immunosorbent assay (ELISA). The expression of hepatic hepcidin mRNA was examined by real-time polymerase chain reaction analysis. The protein levels of divalent metal transporter 1 (DMT1), ferroportin1 (FPN1), and heme-carrier protein 1 (HCP1) of duodenum epithelium were examined by Western blot. The results showed that the amount of iron and ferritin in serum were lower in EG than in CG (p < .05). The levels of IL-6 and white blood cells were greater in EG than in CG (p < .01). The expression of DMT1, HCP1, and FPN1 was significantly lower in EG than in CG (p < .01). The mRNA expressions of hepatic hepcidin and hemojuvelin in skeletal muscle were remarkably higher in EG than in CG. The data indicated that inflammation was induced by strenuous exercise, and as a result, the transcriptional level of the hepatic hepcidin gene was increased, which further inhibited the expression of iron-absorption proteins and led to exercise-associated anemia.