Interval training has more negative effects on sleep in adolescent speed skaters: a randomized cross controlled trial.

Objective: Sleep is an essential component of athletic performance and recovery. This study aimed to investigate the effects of different types of high-intensity exercise on sleep parameters in adolescent speed skaters. Methods: Eighteen male adolescent speed skaters underwent aerobic capacity testing, Wingate testing, and interval training in a randomized crossover design to assess strength output, heart rate, and blood lactate levels during exercise. Sleep quality after each type of exercise was evaluated using the Firstbeat Bodyguard 3 monitor. Results: The results showed that Wingate testing and interval training led to decreased sleep duration, increased duration of stress, decreased RMSSD, and increased LF/HF ratio (p < 0.01). Conversely, aerobic capacity testing did not significantly affect sleep (p > 0.05). The impact of interval training on sleep parameters was more significant compared to aerobic capacity testing (p < 0.01) and Wingate testing (p < 0.01). Conclusion: High-intensity anaerobic exercise has a profound impact on athletes' sleep, primarily resulting in decreased sleep duration, increased stress duration, decreased RMSSD, and increased LF/HF ratio.

Trimethylamine N-Oxide Improves Exercise Performance by Reducing Oxidative Stress through Activation of the Nrf2 Signaling Pathway.

Trimethylamine N-oxide (TMAO) has attracted interest because of its association with cardiovascular disease and diabetes, and evidence for the beneficial effects of TMAO is accumulating. This study investigates the role of TMAO in improving exercise performance and elucidates the underlying molecular mechanisms. Using C2C12 cells, we established an oxidative stress model and administered TMAO treatment. Our results indicate that TMAO significantly protects myoblasts from oxidative stress-induced damage by increasing the expression of Nrf2, heme oxygenase-1 (HO-1), NAD(P)H dehydrogenase (NQO1), and catalase (CAT). In particular, suppression of Nrf2 resulted in a loss of the protective effects of TMAO and a significant decrease in the expression levels of Nrf2, HO-1, and NQO1. In addition, we evaluated the effects of TMAO in an exhaustive swimming test in mice. TMAO treatment significantly prolonged swimming endurance, increased glutathione and taurine levels, enhanced glutathione peroxidase activity, and increased the expression of Nrf2 and its downstream antioxidant genes, including HO-1, NQO1, and CAT, in skeletal muscle. These findings underscore the potential of TMAO to counteract exercise-induced oxidative stress. This research provides new insights into the ability of TMAO to alleviate exercise-induced oxidative stress via the Nrf2 signaling pathway, providing a valuable framework for the development of sports nutrition supplements aimed at mitigating oxidative stress.

Spatial-temporal evolution of overweight and obesity among Chinese adolescents from 2016 to 2020.

This study examines the spatial-temporal evolution of overweight and obesity among Chinese adolescents aged 14-17. Data from five national surveys conducted between 2016 and 2020 were analyzed to determine distribution patterns and trends. Results showed that overweight and obesity exhibit spatial clustering, with greater severity in the north and less severity in the south. The issue has spread from the northeast to the southwest of Mainland China. Using a local autocorrelation model, the regions were divided into a northern disease cold spot area (Inner Mongolia) and a southern disease hot spot area (Guangxi). Over the past five years, overweight rates among Chinese adolescents have not been effectively curbed, but obesity has shown some success in control and reversal until 2019. Future efforts should focus on the spatial-temporal pattern of disease spread, targeting hotspot areas and abnormal values for regional synergy and precise prevention and control.

Effect of web-implemented exercise interventions on depression and anxiety in patients with neurological disorders: a systematic review and meta-analysis.

Introduction: Web-implemented exercise intervention is the latest and innovative method to improve people's mental health. Currently, many studies have proven that web-implemented interventions are effective to improve depression and anxiety in adults. However, the influence of different web-implemented exercise interventions on depression and anxiety in patients with neurological disorders is still unclear. Objective: The study aims to systematically summarize the type and content of web-implemented exercise interventions and quantify the effect of different web-implemented exercise interventions on depression and anxiety in patients with neurological disorders. Methods: Four literature databases (PubMed, Web of Science, China National Knowledge Infrastructure, and WanFang data) were searched. The literature search considered studies published in English or Chinese before October 13, 2022. Randomized controlled trials (RCTs) that participants accepted web-implemented interventions were included. Two authors independently extracted data and assessed the risk of bias for included studies. Standardized mean differences (SMD) with 95% CI were used to integrate the effect size. Results: 16 RCTs (a total of 963 participants) were included. The results showed that web-implemented exercise intervention had a significant effect on depression (SMD = -0.80; 95% CI, -1.09 to -0.52; I2 = 75%; P < 0.00001) and anxiety (SMD = -0.80; 95% CI, -1.23 to -0.36; I2 = 75%; P = 0.0003) in patients with a neurological disorder. The subgroup analysis showed that the effectiveness of the web-implemented exercise intervention was influenced by several factors, such as web-implemented exercise intervention type, component, and intervention duration. Conclusion: Web-implemented exercise intervention has a relieving effect on depression and anxiety symptoms in patients with neurological disorders. Additionally, the intervention type, intervention duration, and component can influence the effect size. Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/#recordDetails, identifier: CRD42023409538.

Knowledge, attitude, and practice of body shape and fitness among university students in China.

BACKGROUND: Body shape and fitness (BSF) is critical for overall well-being, while university students in China are subjected to stress, peer pressure, performance anxiety, busy schedules, and lack of sleep, which can easily lead to poor BSF. This study aimed to explore the knowledge, attitude, and practice of BSF and related factors among university students in China. METHODS: This web-based cross-sectional study was conducted on students of 15 universities in China between September 1st and November 30th, 2022. The KAP scores were evaluated using a 38-item questionnaire, including social demography, knowledge, attitude, and practice. Univariable and multivariable regression analyses were performed to identify the factors associated with KAP. RESULTS: A total of 995 valid questionnaires were collected. There were 431 (43.3%) males and 564 (56.7%) females. Most participants were sophomores (51.2%) and freshmen (36.3%). Most participants had a BMI of 18-24 kg/m2 (66.1%). The students scored highly on BSF-related knowledge (8.30 ± 1.49), moderately on attitude (37.20 ± 4.46), and low on practice (19.64 ± 4.62). Multivariate logistic regression analysis showed that attitude score (P = 0.001), sex (P = 0.001), grade (P = 0.011), body mass index (BMI) (P < 0.050), parent's education level (P = 0.005), monthly allowance (P < 0.050), and sleep quality and habits (P = 0.016) were independently associated with practice scores. CONCLUSIONS: University students in China were found to have good knowledge, moderate attitude, and poor practice toward BSF. Attitude, sex, grade, BMI, parents' education, monthly living expenses, and sleep quality and habits affected their practice. More BSF-related courses or activities are required to motivate students, especially females.

Spatial Heterogeneity and Regional Clustering of Factors Influencing Chinese Adolescents' Physical Fitness.

There is often significant spatial heterogeneity in the factors influencing physical fitness in adolescents, yet less attention has been paid to this in established studies. Based on the 2018 Chinese National Student Physical Fitness Standard Test data, this study uses a multi-scale, geographically weighted regression (MGWR) model combined with a K-means clustering algorithm to construct a spatial regression model of the factors influencing adolescent physical fitness, and to investigate the degree of spatial variation in the physical fitness of Chinese adolescents from a socio-ecological perspective of health promotion. The following conclusions were drawn: the performance of the youth physical fitness regression model was significantly improved after taking spatial scale and heterogeneity into account. At the provincial scale, the non-farm output, average altitude, and precipitation of each region were strongly related to youth physical fitness, and each influencing factor generally showed a banded spatial heterogeneity pattern, which can be summarized into four types: N-S, E-W, NE-SW, and SE-NW. From the perspective of youth physical fitness, China can be divided into three regions of influence: the socio-economic-influenced region, mainly including the eastern region and some of the central provinces of China; the natural-environment-influenced region, which mainly includes the northwestern part of China and some provinces in the highland region; and the multi-factor joint-influenced region, which mainly includes the provinces in the central and northeastern regions of China. Finally, this study provides syndemic suggestions for physical fitness and health promotion for youths in each region.

How to Test the On-Ice Aerobic Capacity of Speed Skaters? An On-Ice Incremental Skating Test for Young Skaters.

Aerobic capacity is important for speed skaters to achieve good results in middle-long distance events. The technical characteristics of speed skating cause intermittent blood flow blockage in the lower limbs. Therefore, an athlete's aerobic capacity on ice may differ from that measured by cycling or running. Now, the on-ice aerobic capacity lacks methods for conducting aerobic capacity tests on ice. Objective: The objective of this study was to develop a method for measuring on-ice aerobic capacity for young athletes and to compare it with the VO2max test on cycling. Methods: This study established a test method for the on-ice aerobic capacity of young, high-level speed skaters with incremental load (on-ice incremental skating test, OIST) through expert interviews and literature review. In the first part, OIST was used to test the aerobic abilities of 65 youth professional speed skaters (51 males and 14 females) on ice and to explore the correlation with their specific performance. The second part compares the relationship between aerobic capacity on ice and aerobic capacity on bicycle of 18 young high-level male athletes. The third part establishes the regression formula of ice ventilation threshold heart rate. The OIST established in this study can evaluate the on-ice aerobic capacity of athletes from National Level and Level 1&2 in China. The athletes' on-ice aerobic capacity indicators were significantly lower than those of the cycling test. However, the values of absolute VO2max and absolute ventilatory threshold had a high correlation (R = 0.532, p < 0.05; R = 0.584, p < 0.05). The regression formula of ventilatory threshold heart rate on ice = 0.921 × HRmax (Cycling test) -9.243. The OIST established in this study meets the characteristics and requirements of the VO2max measurement method. The OIST seems to be able to better evaluate the aerobic capacity of athletes skating on ice. The indicators of maximum oxygen uptake and ventilation threshold in OIST were significantly lower than those in the aerobic cycling test, but there was a good correlation. The aerobic cycling test can be used as an important selection index of the ice aerobic capacity of speed skaters. The regression formula will provide an important basis for coaches to accurately monitor the intensity of ice training.

Multiscale Impact of Environmental and Socio-Economic Factors on Low Physical Fitness among Chinese Adolescents and Regionalized Coping Strategies.

As low physical fitness in adolescents increases their risk of all-cause mortality in future adulthood as well as regional public health budgets, many scholars have studied the factors influencing physical fitness in adolescents. However, the spatial non-stationarity and scale between physical fitness and influencing factors in adolescents are often neglected. To rectify this situation, this study constructed a multi-scale geographically weighted regression model based on data from the China National Student Fitness Survey and the China Statistical Yearbook in 2018 to investigate the spatial patterns of factors influencing low physical fitness among adolescents. The results showed that the influencing factors for measuring the physical fitness of Chinese adolescents had significant spatial heterogeneity and multi-scale effects. The local R2 values were relatively low in the western region of China. Consideration should be given to increasing the lifestyle and ethnic and cultural characteristics of local residents when selecting influencing factors in the future. The physical fitness of men was mainly influenced by socio-economic factors, while that of women was influenced by natural environmental factors. According to the different spatial distribution patterns of MGWR, this study suggests that each region should develop regionalized strategies to cope with the low physical fitness of adolescents, including taking advantage of the natural environment to develop physical fitness promotion projects, accelerating the upgrading of industrial structures in the north-eastern and western regions, and the need to remain cautious of rapid urbanization in the east.

Relationship between body composition and physical condition of children and adolescents / 中国学校卫生

Objective@#To investigate the correlation between fat mass percentage(FM%), fat mass index(FMI), fat free mass index(FFMI), body mass index (BMI) and physical fitness, and to explore the potential value of body composition index in predicting physical exercise level of children and adolescents.@*Methods@#Data came from 2013 revision of National Students Physical Health Standard of Ministry of Education in Beijing. Body composition of 4 069 children and adolescents aged 6-20 years in Beijing was measured by the BIA(inbody 230). FM, FMI, FFMI and BMI were divided into four groups by quartile method. The differences and trends of the four groups were analyzed by graphpad prism 8.0 software.@*Results@#FM% (20.03±10.39) and FMIS [(4.35± 2.84 )kg/m 2] of oys were significantly lower than those of girls, while FFMI [(14.21±4.95)kg/m 2] and BMI [(20.31±4.27) kg/m 2 ] of boys were significantly higher than those of girls( t =-13.36, -7.66, 11.49, 8.16, P <0.01). In boys, with the increase of FM% and FMI, the performance of 50 m, 1 000 m, standing long jump and pull up showed a downward trend; with the increase of FFMI, the performance of 50 m, standing long jump and pull up had an obvious upward trend. In girls, with the increase of FM% and FMI, the 50 m running time was gradually shortened, and the 800 m running time was gradually increasing; High FFMI was associated with higher performance in 50 m running, while no association was observed between FFMI and 800 m running.Four body composition indicators showed no effects on performance of sitting forward flexion and 1 minute sit up.@*Conclusion@#FM%, FMI, FFMI and BMI have a good predictive effect on physical fitness of children and adolescents. Adolescents with higher FFMI, lower FM% and FMI have better muscle burst strength, muscle endurance, flexibility, aerobic ability and anaerobic ability, especially in boys.

Association of Body Compositions and Bone Mineral Density in Chinese Children and Adolescents: Compositional Data Analysis.

The purpose of this study was to investigate the relationship between body compositions and bone mineral density (BMD) and the effect of composition substitution among Chinese children and adolescents without the influence of multicollinearity. A dual-energy X-ray absorptiometry scan was used to determine the amount of truncal fat (TF), nontruncal fat (NTF), fat-free mass (FFM), and BMD. The compositional data analysis and the compositional proportional substitution analysis were conducted to determine the effect of each part of body compositions on BMD and its substitution effects. Four hundred sixty-six (466) (boys: 51.9%) participants completed this cross-sectional study. For girls, in the overweight group, the relationship between TF and the BMD was positive (ß = 2.943e - 01, p = 0.006) while the NTF showed the opposite trend (ß = -2.358e - 01, p = 0.009). When 4% NTF or FFM was substituted by TF, the BMD increased by about 0.1 and 0.05 units (p < 0.05), respectively. For boys, the association between FFM and BMD was statistically positive (ß = 4.091e - 02, p = 0.0001). There was a positive correlation between TF and BMD (ß = 7.963e - 02, p = 0.036). But with the increase of BMI, this correlation shifted in the opposite direction. In conclusion, compared to TF and NTF, FFM had a better protective effect on BMD, especially for boys. The risk of NTF accumulation on BMD was greater than that of TF accumulation. Compared with girls, boys were more sensitive to the amount of TF.

High-intensity interval training changes the expression of muscle RING-finger protein-1 and muscle atrophy F-box proteins and proteins involved in the mechanistic target of rapamycin pathway and autophagy in rat skeletal muscle.

NEW FINDINGS: What is the central question of this study? What are the adaptations of protein synthesis and degradation that occur in skeletal muscle in response to high-intensity interval training (HIIT), and what are the magnitudes of the changes in response to HIIT, compared to moderate-intensity continuous training (MICT), and the mechanisms underlying these changes? What is the main finding and its importance? HIIT is more effective than MICT in altering the expression of muscle RING-finger protein-1 and muscle atrophy F-box, and enhancing the autophagic flux in rat soleus muscle. In addition, HIIT could activate the mechanistic target of rapamycin pathway. These findings suggest that HIIT might be an effective exercise strategy for health promotion in skeletal muscle. ABSTRACT: This study aimed to investigate the impact of high-intensity interval training (HIIT) on the proteins involved in protein synthesis, the ubiquitin-proteasome system (UPS) and autophagy in skeletal muscle of middle-aged rats. Nine-month-old male Wistar rats (n = 56) were randomly divided into three groups: a control (C) group, a moderate-intensity continuous training (MICT) group and a HIIT group. Rats in the training groups ran on treadmills 5 days per week for 8 weeks. The MICT group ran for 50 min at 60% V̇O2max , while the HIIT group ran for 3 min at 80% of V̇O2max six times separated by 3-min periods at 40% V̇O2max . Aerobic endurance, number of autophagosomes and expression of proteins involved in protein synthesis and degradation in the soleus muscle were measured at three time points: before training, after 4 weeks and after 8 weeks of training. Compared to the C group, HIIT and MICT increased the expression of phosphorylated mechanistic target of rapamycin (mTOR) after 8 weeks (P < 0.05 and P < 0.01, respectively). HIIT increased the expression of muscle RING-finger protein-1 (MuRF-1) after 4 weeks (P < 0.01), and decreased its expression after 8 weeks (P < 0.01). Both HIIT and MICT decreased the expression of muscle atrophy F-box (MAFbx) after 4 weeks (P < 0.05). HIIT improved the expression of microtubule-associated protein 1A/1B-light chain 3 (LC3)-II (P < 0.05), and decreased the P62 content (P < 0.01) after 4 weeks. The LC3II/LC3I ratio was increased after 8 weeks (P < 0.01). This study demonstrated that HIIT could activate the mTOR pathway, alter the expression of MuRF-1 and MAFbx proteins, and enhance autophagic flux in soleus muscle of middle-aged rats.

Prevalence of physical fitness in Chinese school-aged children: Findings from the 2016 Physical Activity and Fitness in China-The Youth Study.

PURPOSE: This study was to present the 2016 prevalence estimates of Chinese school-aged children meeting physical fitness standards and to examine differences by sex and residence locales in children who did not meet fitness standards. METHODS: We conducted cross-sectional analyses of 171,991 children and adolescents (boy: 50.0%, Grades 1-12) who participated in the 2016 Physical Activity and Fitness in China-The Youth Study. The main outcomes were fitness measures, assessed by the 2014 revised Chinese National Student Physical Fitness Standard (CNSPFS), covering areas of aerobic capacity, upper body strength, flexibility, body mass index, abdominal strength, and trunk strength. Children's overall physical fitness performance was categorized, per CNSPFS standards, as excellent, good, pass, or no pass. Data on the prevalence of physical fitness categories and not meeting fitness standards (i.e., among children who received a "no pass" mark) were analyzed, through logistic regression, by sex (boy, girl) and residence locales (urban, rural) across 3 school grades (primary, junior middle, and junior high). RESULTS: In 2016, 5.95% of Chinese children and adolescents achieved an "excellent" mark, 25.80% received a "good" rating, 59.90% received a "pass", and 8.35% received a "no pass". Overall, boys were more likely to not pass the fitness standards compared with girls (adjusted odds ratio (aOR) = 1.710; 95% confidence interval (CI): 1.708-1.712) and children living in urban areas were more likely to not pass the standards than those living in rural areas (aOR = 1.298; 95%CI: 1.296-1.299). Consistent patterns of not meeting fitness standards were also found by sex and residence locales across all 3 school grades. CONCLUSION: In the Chinese school-aged population, about 3 in 10 children achieved an "excellent" or "good" fitness standard in 2016, and about 8% of this population did not meet CNSPFS standards. Children living in urban areas were more likely to not meet minimum fitness performance levels, and boys in school were more likely to not meet minimum fitness performance levels than girls.

[Genetic polymorphism in 5'-flanking region of the lactoferrin gene and its associations with mastitis in Chinese Holstein cows].

Bovine lactoferrin (LF) is a multifunctional glycoprotein found in milk, which acts mainly as a defense factor in the mammary gland. Polymorphism has been found in the bovine LF gene. However, there is no report on genetic polymorphism of LF gene and its associations with mastitis in dairy cattle. In this study, the promoter fragment of LF gene containing -926(G/A), -915(T/G), -478(/G), and +72(T/C) mutations were genotyped by the PCR-RFLP and CRS-PCR method. Two hundred and sixty-eight Chinese Holstein cows were screened. Least square linear model (LSM) analysis was applied to evaluate the associations of LF gene with somatic cell score (SCS). The results indicated that the SCS was significantly affected by -478(/G) and +72(T/C), but not by the other two loci (P >0.05). The SCS of cow with genotype AB in +72(T/C) position was significantly lower than that of genotype AA (P<0.01) or AB (P<0.05). In position -478(/G), the cow with genotype CC showed significantly lower SCS in contrast to cow with genotype CD and DD (P < 0.01). In conclusion, genotype AB in position +72(T/C) and genotype CC in position -478(/G) of LF gene were advantageous genotype, which can be used as candidate markers for mastitis resistance selection in dairy cattle.