Using structural equation modeling to examine correlations between health-related physical fitness and cell health among Chinese college students.

INTRODUCTION: College students' physical fitness is likely to be directly related to their cells' health. However, there is a lack of literature on whether the relationship between cell health and college students' physical fitness is direct or indirect. This study used a structural equation modeling (SEM) approach to investigate the connection between cell health and college students' physical fitness. METHODS: This cross-sectional study collected data from 838 volunteers (502 males and 336 females, average age of 18.74 ± 1.5 years) who were college students from the Shandong province of China in July 2023. Initially, we obtained anthropometric measurements and conducted physical fitness tests on the students. Then, we performed Pearson correlation analysis and principal component analysis to screen variables and explore potentially influencing factors. Finally, we examined associations between the variables and determined whether there were direct or indirect influences among factors using SEM. RESULTS: The results revealed a significant correlation between the cell health factor and the muscle strength factor (path coefficient = 0.97; p < 0.001) as well as the fat obesity factor (path coefficient = -0.52; p < 0.001). The cardiovascular factor exhibited a weak correlation with the cell health factor (path coefficient = 0.11; p < 0.01). Moreover, the cardiovascular factor acted as a mediating variable between the muscle strength factor and the cell health factor, with a positive correlation observed between the muscle strength factor and the cell health factor (path coefficient = 0.40; p < 0.001). CONCLUSION: These findings suggest that cell health is indicative of muscle strength and cardiorespiratory fitness. Our findings demonstrate that assessing the cell health of college students can be a valuable method for evaluating their overall health.

Transforming performance: The impact of an 8-week complex training program on strength, power, and change of direction in female basketball athletes.

BACKGROUND: This study aimed to investigate the effect of complex training on the strength, power, and change of direction (COD) performance of college female basketball athletes. METHODS: This design used experimental and randomized studies. A total of 32 female basketball players volunteered to participate in this study and were randomly allocated to a complex training group (CT group: n = 16) and a resistance training group (RT group: n = 16). The CT group performed CT and the RT group completed RT for 8 weeks. The CT and RT programs were developed based on the linear periodization theory, which required participants to train 2 times a week in the first 4 weeks and 3 times a week in the following 4 weeks. All participants were tested using the 5-0-5 COD test, Illinois agility test (IAT), one-repetition maximum back squat (1RM BS) test, and countermovement jump (CMJ) test before and after the 8-week training period. RESULTS: Two-way repeated measure ANOVA showed a significant group × time interaction for the 5-0-5 COD, IAT, 1RM BS, and CMJ results after the intervention compared with that before the intervention (P < .05) in the CT group (effect size = 0.86-4.04). CT compared with RT caused remarkably larger enhancements in the IAT (P < .001) and CMJ (P = .040) scores. CONCLUSION: Our findings indicate that the implementation of CT could be a promising and innovative intervention for enhancing the strength, power, and COD performance of female basketball players.

A comparative study of 8-week complex training and resistance training on athletic performance of amateur futsal players.

Background: Despite the acknowledged importance of resistance training (RT) in enhancing physical performance in futsal players., the comparative effectiveness of RT and complex training (CT) on both physical and technical performance in futsal players remains underexplored. This study aimed to compare the effects of RT vs. CT on physical and technical performance in amateur futsal players. Method: Players from two amateur futsal teams were assigned to RT (one team of 16 players; 18 years) and CT (one team of 16 players; 18 years) to perform an 8-week intervention with two weekly sessions. The RT performed the squat and deadlift (6 sets of 6-10 repetitions at 75%-85% one-repetition maximum (1RM), while the CT performed the squat + squat jump and deadlift + high pull (3 sets of 4-6 + 10-12 repetitions at 75%-85% 1RM). Pre- and post-intervention assessments included the Futsal Special Performance Test (FSPT), repeated sprint ability (RSA), sprint decrement (Sdec), sprint times at 10-m (T10), 10-20-m (T10-20), and 20-m (T20), 1RM back squat (1RM BS), isometric mid-thigh pull (IMTP), and countermovement jump (CMJ). Results: At baseline, no significant differences between groups were observed for any variable analyzed (p > 0.05). After 8 weeks, there were significant differences between CT vs. RT on FSPT (-10.8% vs. -3.4%; p < 0.05), T10 (-5.2% vs. -0.1%; p < 0.05), IMTP (7.8% vs. 5.1%; p < 0.05), and CMJ (10.2% vs. 4.5%; p < 0.05). On the other hand, no significant differences between CT vs. RT were observed for RSA (-2.0% vs. -1.2%; p > 0.05), Sdec (-7.6% vs. -3.5%; p > 0.05), T10-20 (-0.9% vs. -0.9%; p > 0.05), T20 (-1.8% vs. -1.7%; p > 0.05), and 1RM BS (5.7% vs. 4.5%; p > 0.05) after the training program. Both groups significantly improved FSPT, T20, 1RM BS, and IMTP, while only CT significantly improved RSA, Sdec, T10, and CMJ. Conclusion: The results suggest that CT may be valuable for improving specific performance parameters in amateur futsal players, with some advantages over RT in enhancing strength and power. These findings support tailored training protocols for futsal players to optimize performance.

Is the COVID-19 epidemic affecting the body mass of Chinese teenagers? - A longitudinal follow-up study.

Background: After the spread and outbreak of COVID-19 worldwide, the learning, lifestyle, and health level of young individuals have been immensely impacted. With regard to the existing studies, the development trend of adolescents' body shape in the late COVID-19 period is not sufficiently analyzed, and relevant targeted investigation is lacking. This study aimed to explore the body mass index (BMI) changes of 6-14 years-old adolescents before and after the COVID-19 epidemic, and to provide a reference for promoting the continuous enhancement of adolescent health. Methods: The BMI and related data pertaining to 93,046 individuals from 2019 to 2022 were collected by cluster sampling, and changes in the BMI Z score and detection rate of overweight and obese adolescents before and after the epidemic were analyzed. Furthermore, the trend of obesity rates among adolescents in Jinan from 2019 to 2022 was analyzed using a logistic regression analysis model. Results: The one-way ANOVA models indicated that the BMI Z score of 6-14 years-old adolescents in 2020 significantly increased compared to 2019 (p < 0.01), and decreased in 2021 and 2022; in 2020, the obesity rate of adolescents exhibited a significant increase; however, the rate decreased after being controlled in 2021 and 2022. The normal-body size proportion continued to rise (p < 0.01), and adolescents of different age groups and genders exhibited similar development trends; the results of the logistic regression analysis indicate that there was a significant increase in obesity rates in 2020, adolescents of different age groups and genders exhibited similar development trends (p < 0.05). Conclusion: This study demonstrated that the COVID-19 epidemic impacts the BMI and obesity detection rate of adolescents. Adolescents from different age groups and genders exhibited similar development trends.

Cross lagged analysis of adolescent social adaptability, physical exercise and mental health / 中国学校卫生

Objective@#To explore the relationships among social adaptation, physical exercise, and mental health of adolescents, so as to provide theoretical basis for social adaptation and mental health improvement.@*Methods@#Longitudinal follow up survey data were collected from 1 163 adolescents in Jinan City, Shandong Province in September 2021 (T1), January 2022 (T2), and June 2022 (T3) by cluster random sampling method. The relationship between social adaptability, physical exercise, and mental health of adolescents was analyzed through cross lagged analysis.@*Results@#There were significant sex differences in physical exercise and mental health among adolescents on T1, T2, and T3 ( Z =-3.83, -3.43, -4.59; -12.45, -8.93, -8.72, P <0.01), with male students had more physical exercise [35(28,42),36(33,42),38(35,43)] and better mental health [12(12,17),17(17,21),14(14,26)] levels than female students [33(27,40),35(31,40),36(33,41); 9(9,12),12(12,23),12(12,23)]. No similar sex difference in social adaptability (T1, T2, T3) [male: 22 (14, 24), 22 (14, 24), 22 (16, 24); female: 21 (11, 23), 20 (14, 24), 22 (17, 24)] ( Z =-0.79, -1.19, -1.34, P >0.05). Temporal and synchronous correlations were found in social adaptability, physical exercise and mental health ( r =0.18-0.67，0.12-0.68, P <0.01). Teenager physical exercise and mental health could predict social adaptability across time ( β T1-T2 =0.25,0.13; β T2-T3 =0.25,0.06, P <0.05), with a mediating effect on the impact path of physical exercise on social adaptability in psychological health ( β =0.14, P <0.05).@*Conclusions@#There is a causal relationship between physical exercise, mental health, and social adaptability among adolescents. Encouraging adolescents to actively participate in physical exercise and promoting mental health can effectively enhance their social adaptability.

Changes in physical health among primary and secondary school students in Jinan City during 2019 to 2022 / 中国学校卫生

Objective@#To analyze the changes in physical health among primary and secondary school students in Jinan during 2019 to 2022, so as to provide reference for primary and secondary school students physical health promotion.@*Methods@#From 2019 to 2022，16 496 primary and junior middle school students will be selected from Jinan by cluster random sampling method, the comprehensive scores of physical health for each year were calculated according to the National Student Physical Health Standards (revised in 2014), and changes in physical health were analyzed using t-tests, univariate analysis, analysis of covariance and χ 2 tests.@*Results@#The students physical health scores ranged from high to low in 2022（80.78±12.63），2021（79.12±12.72），2019 （75.17±2.03）and 2020（73.82±12.63）. During 2019 to 2022, the overall physical health score of female students were higher than that of male students ( F=105.39, 288.29, 197.90, 159.36, P <0.01). The differences in the comprehensive physical and health scores of male and female students in different grades from 2019 to 2022 were statistically significant ( F=34.22, 34.96, 20.33, 45.08 , 13.56, 18.29, 24.86, 30.01, P <0.01). The individual indicators showed varying degrees of decline in 2020. Except for body mass index (BMI), the fluctuations in lung s capacity, run 50 meters, sit forward, standing long jump, 1 minute sit-ups, pull-up, endurance running, 1 minute skipping rope during 2019 to 2022 were statistically significant (primary school: F =127.58, 44.80, 223.64, 76.66, 10.69, 296.79, secondary school: F =189.31, 52.10, 63.12, 61.49, 7.34, 8.10, 50.94 , P <0.01). The detection rates of overweight and obesity in primary and secondary school students from 2019 to 2022 were 30.09 %, 31.45%, 30.14 %, and 30.60%, respectively ( χ 2=2.26, P >0.05). From 2019 to 2022, the rates of overweight and obesity in primary and middle school boys were 34.56 %, 34.66%, 32.14%, 33.73%, 37.41%, 43.53%, 41.36 %, 39.16%, respectively, and the rates of overweight and obesity in primary and middle school girls were 24.66%, 24.39%, 24.61%, 24.65%, 23.82%, 28.74%, 26.99 %, 27.95%, respectively, none of which were statistically significant ( χ 2=2.93, 4.29 , 0.04, 3.12, P >0.05).@*Conclusion@#During 2019 to 2022, there are no significant changes in physical health indicators among primary and secondary school students in Jinan, and the overall level of physical health recovered rapidly after a slight decline due to the COVID-19 epidemic.

Association between BMI and health-related physical fitness: A cross-sectional study in Chinese high school students.

Background: Existing studies reporting on the levels of physical fitness among high school students use relatively few fitness tests for indicators of physical fitness, thus, incomprehensively evaluating the levels of physical fitness. Therefore, this study investigated the relationship between body mass index (BMI) and physical fitness index (PFI) by investigating five physical fitness indicators and calculating PHI. Method: Anthropometric measurements and indicators from five measures of physical fitness (50-m sprint, sit and reach, standing long jump, 800/1,000-m run, pull-up/bent-leg sit-up) were assessed. BMI was calculated to classify individuals into underweight, normal weight, overweight, and obese categories. Z-scores based on sex-specific mean and standard deviation were calculated, and the sum of Z-scores from the six fitness tests indicated the PFI. The findings were fitted to a linear regression model to elucidate the potential relationship between BMI and PFI. Results: In total, 176,655 high school students (male: 88,243, female: 88,412, age: 17.1 ± 1.05 years, height: 168.87 ± 11.1 cm, weight: 62.54 ± 15.15 kg) in Jinan, China, completed the physical fitness tests between 2020 and 2021. The one-way ANOVA models showed that PFI in the normal category was significantly higher as compared to all the other BMI categories within both male and female groups (p < 0.001), and PFI in the obese category was significantly lower as compared to all the other BMI categories for both male and female groups (p < 0.001). The association between PFI and BMI showed an inverted U-shape relationship. Conclusions: This study demonstrated that BMI affects the PFI in both males and females. As compared to the obese and overweight categories based on BMI, significantly higher scores of PFI were observed for males and females.

Methionine-Based pH and Oxidation Dual-Responsive Block Copolymer: Synthesis and Fabrication of Protein Nanogels.

In this paper, we synthesized a block copolymer containing pendent thioether functionalities by reversible addition-fragmentation chain transfer polymerization of a tert-butyloxycarbonyl (Boc)-l-methionine-(2-methacryloylethyl)ester (Boc-METMA) monomer using a poly(ethylene glycol) (PEG)-based chain transfer agent. The deprotection of Boc groups resulted in an oxidation and pH dual-responsive cationic block copolymer PEG-b-P(METMA). The block copolymer PEG-b-P(METMA) possessing protonable amine groups was water-soluble at pH < 6.0 and self-assembled to form spherical micelles at pH > 6.0. In the presence of H2O2, the micelles first became highly swollen with time and completely disassembled at last, demonstrating the H2O2-responsive feature because of the oxidation of hydrophobic thioether to hydrophilic sulfoxide. The anticancer drug curcumin (Cur) was entrapped in the polymeric micelles and the Cur-loaded micelles displayed a H2O2-triggered release profile as well as a pH-dependent release behavior, making PEG-b-P(METMA) micelles promising nanocarriers for reactive oxygen species-responsive drug delivery. Taking advantage of the protonated amine groups, the cationic polyelectrolyte PEG-b-P(METMA) formed polyion complex micelles with glucose oxidase (GOx) through electrostatic interactions at pH 5.8. By cross-linking the cores of PIC micelles with glutaraldehyde, the PIC micelles were fixed to generate stable GOx nanogels under physiological conditions. The GOx nanogels were glucose-responsive and exhibited glucose-dependent H2O2-generation activity in vitro and improved storage and thermal stability of GOx. Cur can be encapsulated in the GOx nanogels, and the Cur-loaded GOx nanogels demonstrate the glucose-responsive release profile. The GOx nanogels displayed high cytotoxicity to 4T1 cells and were effectively internalized by the cells. Therefore, these GOx nanogels have potential applications in the areas of cancer starvation and oxidation therapy.