A mixed-studies systematic review and meta-analysis of school-based interventions to promote physical activity and/or reduce sedentary time in children

Purpose:The aim of this mixed-studies systematic review was to ascertain the effectiveness of school-based interventions in increasing physical activity(PA) and/or reducing sedentary time(ST) in children aged 5-11 years,as well as to explore their effectiveness in relation to categories of the theory of expanded,extended,and enhanced opportunity(TEO).Methods:Adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA) guidelines,5 databases were searched using predefined search terms.Following title and abstract screening of 1115 records,the removal of duplicates(n=584) and articles that did not meet the inclusion criteria agreed to a priori(n=419) resulted in 112 records that were full-text screened.Two independent reviewers subsequently used the mixed-methods appraisal tool to assess the methodological quality of 57 full-text studies that met the inclusion criteria after full-text screening.The interventions were summarised using the TIDierR checklist and TEO.The strength of evidence was determined using a 5-level rating system utilising a published decision tree.Results:Overall evidence ratings for interventions implemented within school settings were:no evidence of effects on moderate-to-vigorous physical activity(MVPA) and inconclusive evidence of effects on sedentary time.In relation to the TEO,expansion of PA appeared to be the most promising intervention type for MVPA,with moderate evidence of effect,whereas extension and enhancement of PA opportunity demonstrated no evidence of effect.A critical issue of possible compensatory behavior was identified by analysis of intervention effect in relation to PA measurement duration;when studies measured changes in PA during the actual intervention,there was moderate evidence of effect,whereas those that measured changes in PA during the school day presented inconclusive evidence of effect,and those that measured changes in PA over a whole day yielded no evidence of effect.Two meta-analyses of those studies using a whole-day accelerometer measure for MVPA or ST showed a significant but moderate effect for MVPA(effect size=0.51;95% confidence interval(CI):0.02-0.99) and a large but nonsignificant effect for ST(effect size=1.15;95%CI:-1.03 to 3.33);both meta-analyses demonstrated low precision,considerable inconsistency,and high heterogeneity.Conclusion:The findings have important implications for future intervention research in terms of intervention design,implementation,and evaluation.

2024 Wheelchair Compendium of Physical Activities:An update of activity codes and energy expenditure values

Purpose:This paper presents an update of the 2011 Wheelchair Compendium of Physical Activities designed for wheelchair users and is referred to as the 2024 Wheelchair Compendium.The Wheelchair Compendium aims to curate existing knowledge of the energy expenditure for wheelchair physical activities(PAs).Methods:A systematic review of the published energy expenditure of PA for wheelchair users was completed between 2011 and May 2023.We added these data to the 2011 Wheelchair Compendium data that was compiled previously in a systematic review through 2011.Results:A total of 47 studies were included,and 124 different wheelchair PA reported energy expenditure values ranging from 0.8 metabolic equivalents for wheelchair users(filing papers,light effort)to 11.8 metabolic equivalents for wheelchair users(Nordic sit skiing).Conclusion:In introducing the updated 2024 Wheelchair Compendium,we hope to bridge the resource gap and challenge the prevailing narratives that inadvertently exclude wheelchair users from physical fitness and health PAs.

Influence of different sports on fat mass and lean mass in growing girls

Purpose: The aim of this study was to analyze and compare the effects of different sports(swimming, football, basketball, and handball) on fat mass and lean mass in prepubertal and pubertal girls.Methods: Two hundred girls(10.6 ± 1.5 years old, Tanner stages I–III) participated in the study and were divided into 5 groups: 40 swimmers, 40 football players, 40 basketball players, 40 handball players, and 40 controls. Fat and lean masses at whole body, arms, trunk, and legs were measured using dual-energy X-ray absorptiometry(DXA). Pubertal status was determined using Tanner test. Effects of different sports on fat and lean masses were assessed through analysis of covariance with height as covariates. Analyses were performed separately in 2 groups depending on the Tanner stage(prepubertal and pubertal).Results: The girls of the control group had less lean mass and more fat mass compared to the girls who play sports(p < 0.05). There were differences in body fat between sports. The swimmers and football players had less body fat(p < 0.05). On the other hand, handball players showed the highest values in lean mass(p < 0.05).Conclusion: Impact sports(football, basketball, and handball) and low-impact sports(swimming) provide an appropriate development of lean mass in growing girls. We can conclude that people practicing sports at early ages ensure a lower fat mass and higher lean mass compared to those who do not practice. These results may be useful as a preventive method of adult obesity.

Deconstructing athletes’sleep:A systematic review of the influence of age,sex,athletic expertise,sport type,and season on sleep characteristics

Purpose:This systematic review aimed to describe objective sleep parameters for athletes under different conditions and address potential sleep issues in this specific population.Methods:PubMed and Scopus were searched from inception to April 2019.Included studies measured sleep only via objective evaluation tools such as polysomnography or actigraphy.The modified version of the Newcastle-Ottawa Scale was used for the quality assessment of the studies.Results:Eighty-one studies were included,of which 56 were classified as medium quality,5 studies as low quality,and 20 studies as high quality.A total of 1830 athletes were monitored over 18,958 nights.Average values for sleep-related parameters were calculated for all athletes according to sex,age,athletic expertise level,training season,and type of sport.Athletes slept on average 7.2±1.1 h/night(mean±SD),with 86.3%±6.8%sleep efficiency(SE).In all datasets,the athletes’mean total sleep time was<8 h.SE was low for young athletes(80.3%±8.8%).Reduced SE was attributed to high wake after sleep onset rather than sleep onset latency.During heavy training periods,sleep duration and SE were on average 36 min and 0.8%less compared to pre-season and 42 min and 3.0%less compared to in-season training periods,respectively.Conclusion:Athletes’sleep duration was found to be short with low SE,in comparison to the general consensus for non-athlete healthy adults.Notable sleep issues were revealed in young athletes.Sleep quality and architecture tend to change across different training periods.

Direct and indirect effects of multilevel factors on school-based physical activity among Japanese adolescent boys

Purpose: Background: Physical activity is a complex behavior which involves the interaction of multilevel factors at the individual, social and environmental level. However, previous studies have largely focused on psychological and/or social environmental factors and the direct impact of such factors on physical activity. There are few studies having examined how multilevel factors may interact to influence activity level. Therefore, the purpose of the present study was to examine both direct and indirect effects of multilevel factors on school-based physical activity in Japanese adolescent boys. Methods: In this cross-sectional survey of the Japanese adolescent lifestyles, 379 junior high school boys were invited to complete self-report measures of age, grade, weight, height, self-efficacy, social support (family, friends and teachers), school physical environment (equipment, facilities and safety) and average minutes per week of physical activity during lunch time and after-school hours occurring at school. Structural equation modeling analyses controlling for age were utilized to examine the effects of body mass index (BMI), self-efficacy, social support and school physical environmental variables on lunchtime and after-school physical activity. Results: During lunch time, self-efficacy exhibited direct positive effects on physical activity. BMI, facilities, and safety were indirectly associated with lunchtime physical activity through self-efficacy. However, there were no significant relationships of equipment and social support with lunchtime physical activity. During after-school hours, family support and facilities directly affected physical activity. Self-efficacy was indirectly related with physical activity through family support. BMI, equipment, and safety indirectly affected physical activity through self-efficacy and/or family support. Conclusion: Effects of multilevel factor on physical activity among adolescent boys differed according to context, which implies that interventions to promote physical activity should be context-specific. Findings encourage the development of future effective interventions to promote physical activity through self-efficacy during lunch time as well as family support during after-school hours.

Mediation effects of social support on relationships of perceived environment and self-efficacy with school-based physical activity: A structural equation model tailored for Japanese adolescent girls

Background: Identifying correlates of physical activity that can be targeted as potential mediators is important for developing interventions to promote physical activity in adolescent girls. However, the mediated effects of multilevel correlates of physical activity remain poorly understood. Therefore, the present study aimed to examine direct and mediated effects of personal, social and perceived school physical environmental factors on school-based physical activity of Japanese adolescent girls. Methods: In this cross-sectional survey of the Japanese adolescent lifestyles, 344 junior high school girls were invited to complete self-report measures of age, grade, weight, height, self-efficacy, social support (family, friends and teachers), perceived school physical environment (equipment, facilities and safety) and physical activity at school (min per week during lunch time and after- school hours). Structural equation modeling analysis controlling for age was performed to examine the effects of body mass index (BMI), self-efficacy, social support and school physical environmental variables on lunchtime and after-hours physical activity. Results: The final structural model demonstrated an acceptable fit for each context-specific physical activity. During lunch recess, perceived equipment and friend support exhibited direct effects on physical activity;perceived facilities, safety, and self-efficacy were indirectly associated with physical activity through friend support. During after-school hours, both family and friend support directly affected physical activity at school;perceived safety, facilities and self-efficacy exhibited indirect effects on physical activity through family or friend support. However, there were no significant associations between equipment and after-school-hours physical activity. Regardless of contexts, BMI had neither direct nor indirect effects on physical activity. Conclusion: Social support from family and friends was identified as factors mediating the effects of perceived environment and self-efficacy on school-based physical activity among Japanese adolescent girls. This finding encourages the future development of effective interventions to promote physical activity through family and friend support in the future.

A Framework for Designing and Managing a Best-of-N Sports Tournament

A framework is provided for analyzing the time and resource requirements for a tournament where matches are played to a best-of-N format, to ensure maximal use of available facilities and a maximal number of competitors. A baseline of average length of games and number of games played per match is necessary. The analysis informing development of the framework was carried out in the context of the sport of golf croquet. Based on the results of this analysis, golf croquet tournaments should have four best-of-three matches scheduled per court per day to optimize playing time and minimize the need to play matches outside regular playing hours.

O-linkedβ-N-acetylglucosaminylation may be a key regulatory factor in promoting osteogenic differentiation of bone marrow mesenchymal stromal cells

Cumulative evidence suggests that O-linkedβ-N-acetylglucosaminylation(OGlcNAcylation)plays an important regulatory role in pathophysiological processes.Although the regulatory mechanisms of O-GlcNAcylation in tumors have been gradually elucidated,the potential mechanisms of O-GlcNAcylation in bone metabolism,particularly,in the osteogenic differentiation of bone marrow mesenchymal stromal cells(BMSCs)remains unexplored.In this study,the literature related to O-GlcNAcylation and BMSC osteogenic differentiation was reviewed,assuming that it could trigger more scholars to focus on research related to OGlcNAcylation and bone metabolism and provide insights into the development of novel therapeutic targets for bone metabolism disorders such as osteoporosis.

Effects of total soy saponins on free radicals in the quadriceps femoris,serum testosterone,LDH,and BUN of exhausted rats

Purpose:The aim of this study was to investigate the impact of total soy saponins(TS) on the free radical metabolism from the quadriceps femoris muscle,serum testosterone,lactate dehydrogenase(LDH),and blood urea nitrogen(BUN) in rats exercised to exhaustion.Methods:A one-time exhausted treadmill exercise session was used.Sprague-Dawley rats were divided into 4 groups:a control group—animals receiving no TS and no exercise(NTSNE),animals receiving TS but no exercise group(TSNE),animals receiving no TS but exercised to exhaustion group(NTSE),and animals receiving TS and exercised to exhaustion group(TSE).The TSNE and TSE groups were fed TS at a dosage of 20 mg/kg body weight once per day for 2 weeks.The NTSE group was given a placebo,and the NTSNE group was not given any treatment.The NTSE and TSE groups were exercised at speed of 30 m/min on treadmill until exhausted.The exercise time and exercise distance were recorded when the rats became exhausted and the rats were then decapitated and anatomized immediately.A 10% homogenate of the quadriceps femoris tissue was prepared.The levels of superoxide dismutase(SOD),catalase(CAT),malondialdehyde(MDA),glutathione peroxidase(GSH-Px),glutathione reductase(GR),reduced glutathione(GSH),total antioxidant capacity(T-AOC),LDH,BUN,and serum testosterone were tested.Results:TS significantly increased the exercise time to exhaustion by 20.62%(p < 0.05).The MDA levels were decreased significantly in the TSNE group than in NTSNE group(p < 0.05);the T-AOC levels increased significantly in the TSNE group than in the other 3 groups(p < 0.01,p < 0.05,p < 0.05).The LDH activity significantly increased in the NTSE group than in TSNE group(p < 0.05).The BUN levels significantly increased in the NTSE group than in the other 3 groups(p < 0.01,p < 0.01,p < 0.05),and significantly increased in the TSE group than in NTSNE and TSNE groups(both p < 0.01).The serum testosterone levels increased significantly in the TSNE group than in the other 3 groups(all p < 0.01).SOD,CAT,GSH-Px,GR,and GSH were not statistically different among the groups.Conclusion:TS can significantly improve the exercised rats' serum testosterone level and antioxidant activity in their quadriceps femoris to varying degrees,decrease MDA and serum LDH and BUN levels,increase the exercise time,and delay the occurrence of the fatigue.

Physical literacy in the field of physical education——A challenge and a possibility

Publications of articles with physical literacy as a topic have increased dramatically since the beginning of 2000 s. The aim of this paper is to,through an explorative literature overview with an inductive approach, analyze frequent, and significant themes in published peer reviewed articles,with a focus on physical literacy. The database EBSCO has been used with the identifiers “physical literacy” and “physical literacy and evidence”.Furthermore ICSSPE Bulletin＇s special issue on physical literacy has been included in the overview. The findings have resulted in three key themes： assumptions of the concept physical literacy and its educative role, sports development and physical literacy, and assessment and physical literacy. Future studies are needed to examine if the advocated pedagogical strategies based on the concept physical literacy have led to a reorganized and revitalized school subject. There is also an existing critique towards making physical literacy an idealistic neutral concept or synonym with fundamental movement skills or sports talent identification. The role of higher education emerges as crucial for the next step of the development of the scientific framework as this involves how physical literacy will be socially configured, nurtured, and embodied in practice.Copyright ó 2015, Shanghai University of Sport. Production and hosting by Elsevier B.V. All rights reserved.

A systematic review of running-related musculoskeletal injuries in runners

Objective:Running-related musculoskeletal injuries(RRMIs),especially stemming from overuse,frequently occur in runners.This study aimed to systematically review the literature and determine the incidence and prevalence proportion of RRMIs by anatomic location and specific pathology.Methods:An electronic database search with no date beginning restrictions was performed in SPORTDiscus,PubMed,and MEDLINE up to June 2020.Prospective studies were used to find the anatomic location and the incidence proportion of each RRMI,whereas retrospective or cross-sectional studies were used to find the prevalence proportion of each RRMI.A separate analysis for ultramarathon runners was performed.Results:The overall injury incidence and prevalence were 40.2%±18.8%and 44.6%±18.4%(mean±SD),respectively.The knee,ankle,and lower leg accounted for the highest proportion of injury incidence,whereas the knee,lower leg,and foot/toes had the highest proportion of injury prevalence.Achilles tendinopathy(10.3%),medial tibial stress syndrome(9.4%),patellofemoral pain syndrome(6.3%),plantar fasciitis(6.1%),and ankle sprains(5.8%)accounted for the highest proportion of injury incidence,whereas patellofemoral pain syndrome(16.7%),medial tibial stress syndrome(9.1%),plantar fasciitis(7.9%),iliotibial band syndrome(7.9%),and Achilles tendinopathy(6.6%)had the highest proportion of injury prevalence.The ankle(34.5%),knee(28.1%),and lower leg(12.9%)were the 3 most frequently injured sites among ultramarathoners.Conclusion:The injury incidence proportions by anatomic location between ultramarathoners and non-ultramarathoners were not significantly different(p=0.798).The pathologies with the highest incidence proportion of injuries were anterior compartment tendinopathy(19.4%),patellofemoral pain syndrome(15.8%),and Achilles tendinopathy(13.7%).The interpretation of epidemiological data in RRMIs is limited due to several methodological issues encountered.

Total soy saponins improve the antioxidant capacity of the myocardium and exercise ability in exhausted rats

Purpose：The aim of the present study was to investigate the impact of total soy saponins（TS） on the myocardial antioxidant capacity in rats exercised to exhaustion.Methods：The one-time exhausted treadmill model was used.All rats were divided into 4 groups：the control group,the TS group,the exhausted group,and the TS exhausted group.The TS and TS exhausted groups were fed TS at a dosage of 20 mg/kg body weight,once a day,for 2 weeks.The exhausted group was given a placebo,and the control group was not given any treatment.The treadmill speed was set at 30 m/min,and the rats（exhausted and TS exhausted groups） were trained at this speed until exhausted.The rats were decapitated and anatomized immediately after exhausted.A 10% homogenate of the myocardial tissue was prepared.Results：TS significant y increased the exercise time by 20.62%（p〈0.05）.As compared with the control group,the enzyme activities for catalase（CAT）,glutathione peroxidase（GSH-Px）,and glutathione reductase（GR） were significant y enhanced in the TS group（p〈0.01）;GR and GSH-Px activity was significant y enhanced in the TS exhausted group（p〈0.01）;malondialdehyde（MDA） levels were significant y decreased in the TS exhausted group（p〈0.05）.As compared with the exhausted group,the GSH-Px activity was significant y enhanced in the TS exhausted group（p〈0.01）;CAT,GSH-Px,and GR activities were significant y enhanced in the TS group（p〈0.01）.As compared with the TS group,the CAT and GR activity in the TS exhausted group was significant y decreased（p〈0.01）.Conclusion：TS can improve the exercised rats＇ antioxidant activity in their cardiac muscle to varying degrees,decrease MDA and serum AST and LDH levels,increase the exercise time,and delay the occurrence of sports fatigue.

The influence of physiobiomechanical parameters,technical aspects of shooting,and psychophysiological factors on biathlon performance:A review

The biathlon, an Olympic sporting discipline that combines cross-country skiing with rifle marksmanship, entails considerable physiological demands, as well as fine motor control while shooting after intense exercise and under mental pressure. Although much of our knowledge about cross-country skiing is probably also applicable to the biathlon, carrying the rifle and shooting under stress make this discipline somewhat unique. The present review summarizes and examines the scientific literature related to biathlon performance, with a focus on physiological and biomechanical factors and shooting technique, as well as psychophysiological aspects of shooting performance. We conclude with suggestions for future research designed to extend our knowledge about the biathlon, which is presently quite limited.2018 Published by Elsevier B.V. on behalf of Shanghai University of Sport. This is an open access article under the CC BY-NC-ND license. （http：//creativecommons.org/licenses/by-nc-nd/4.0/）.

Physical activity, sedentary behavior, and long-term cardiovascular risk in young people: A review and discussion of methodology in prospective studies

The long-term effects of physical activity （PA） or sedentary behavior on cardiovascular health in young people are not well understood. In this study, we use a narrative format to review the evidence for a prospective association with adiposity and other well-established biological cardiovascular risk factors in healthy young people, considering only studies with at least 2 years of follow-up. PA appears to elicit a long-term beneficial effect on adiposity and particularly markers of cardiovascular health. With adiposity, however, a few studies also reported that higher levels of PA were associated with higher levels of adiposity. Time spent sedentary does not appear to be related to adiposity or markers of cardiovascular health independent of PA. We then discuss the uncertainties in the underlying causal chain and consider a number of alternative modeling strategies, which could improve our understanding of the relationship in future studies. Finally, we consider the current methodology for assessing PA and sedentary time.

Pacing and predictors of performance during cross-country skiing races:A systematic review

Background： Cross-country skiing （XCS） racing, a popular international winter sport, is complex and challenging from physical, technical, and tactical perspectives. Despite the vast amount of research focusing on this sport, no review has yet addressed the pacing strategies of elite XCS racers or the factors that influence their performance. The aim was to review the scientific literature in an attempt to determine the effects of pacing strategy on the performance of elite XCS racers. Methods： Four electronic databases were searched using relevant subject headings and keywords. Only original research articles published in peerreviewed journals and the English language and addressing performance, biomechanics, physiology, and anthropometry of XCS racers were reviewed. Results： All 27 included articles applied correlative designs to study the effectiveness of different pacing strategies. None of the articles involved the use of an experimental design. Furthermore, potential changes in external conditions （e.g.,weather, ski properties） were not taken into consideration. A comparable number of studies focused on the skating or classical technique. In most cases, positive pacing was observed, with certain indications that higher-level athletes and those with more endurance and strength utilized a more even pacing strategy. The ability to achieve and maintain a long cycle length on all types of terrain was an important determinant of performance in all of the included studies, which was not the case for cycle rate. In general, uphill performance was closely related to overall race performance, with uphill performance being most closely correlated to the success of female skiers and performance on flat terrain being more important for male skiers. Moreover, pacing was coupled to the selection and distribution of technique during a race, with faster skiers employing more double poling and kick double poling, less diagonal stride, and more V2 （double dance） than V1 （single dance） skating across a race. Conclusion： We propose that skiers at all levels can improve their performance with more specific training in techniques （i.e., maintaining long cycles without compromising cycle rate and selecting appropriate techniques） in combination with training for endurance and more strength. Furthermore, we would advise less experienced skiers and/or those with lower levels of performance to apply a more even pacing strategy rather than a positive one （i.e., starting the race too fast）.2018 Published by Elsevier B.V. on behalf of Shanghai University of Sport. This is an open access article under the CC BY-NC-ND license. （http：//creativecommons.org/licenses/by-nc-nd/4.0/）.

Genetics of coronary heart disease with reference to ApoAICⅡI-AIV gene region

Cardiovascular diseases are affected by multiple factors like genetic as well as environmental hence they reveal factorial nature. The evidences that genetic factors are susceptible for developing cardiovascular diseases come from twin studies and familial aggregation. Different ethnic populations reveal differences in the prevalence coronary artery disease(CAD) pointing towards the genetic susceptibility. With progression in molecular techniques different developments have been made to comprehend the disease physiology. Molecular markers have also assisted to recognize genes that may provide evidences to evaluate the role of genetic factors in causation of susceptibility towards CAD. Numerous studies suggest the contribution of specific "candidate genes", which correlate with various roles/pathways that are involved in the coronary heart disease. Different studies have revealed that there are large numbers of genes which are involved towards the predisposition of CAD. However, these reports are not consistent. One of the reasons could be weak contribution of genetic susceptibility of these genes. Genome wide associations show different chromosomal locations which dock, earlier unknown, genes which may attribute to CAD. In the present review different ApoAI-CⅡI-AIV gene clusters have been discussed.

Association of accelerometer-derived step volume and intensity with hospitalizations and mortality in older adults:A prospective cohort study

Purpose:This study aimed to examine the associations of accelerometer-derived steps volume and intensity with hospitalizations and all-cause mortality in older adults.Methods:This prospective cohort study involved 768 community-dwelling Spanish older adults(78.8±4.9 years,mean±SD;53.9% females)from the Toledo Study for Healthy Aging(2012-2017).The number of steps per day and step cadence(steps/min) were derived from a hip-mounted accelerometer worn for at least 4 days at baseline.Participants were followed-up over a mean period of 3.1 years for hospitalization and 5.7 years for all-cause mortality.Cox proportional hazards regression models were used to estimate the individual and joint associations between daily steps and stepping intensity with hospitalizations and all-cause mortality.Results:Included participants walked 5835± 3445 steps/day with an intensity of 7.3± 4.1 steps/min.After adjusting for age,sex,body mass index(BMI),education,income,marital status and comorbidities,higher step count(hazard ratio(HR)=0.95,95% confidence interval(95%CI:0.90-1.00,and HR=0.87,95%CI:0.81-0.95 per additional 1000 steps) and higher step intensity(HR=0.95,95%CI:0.91-0.99,and HR=0.89,95%CI:0.84-0.95 per each additional step/min) were associated with fewer hospitalizations and all-cause mortality risk,respectively.Compared to the group having low step volume and intensity,individuals in the group having high step volume and intensity had a lower risk of hospitalization(HR=0.72,95%CI:0.52-0.98) and all-cause mortality(HR=0.60,95%CI:0.37-0.98).Conclusion:Among older adults,both high step volume and step intensity were significantly associated with lower hospitalization and all-cause mortality risk.Increasing step volume and intensity may benefit older people.

Measurement invariance and latent mean differences of the Chinese version physical activity self-efficacy scale across gender and education levels

Background: Self-efficacy has been identified as an important determinant of youth's behavior change including physical activity(PA) participation. However, the dimensionality check of a PA self-efficacy scale has rarely been conducted in China. The current study aims to examine(1) the unidimensionality of a shortened Chinese version of PA self-efficacy scale(S-PASESC);(2) the measurement invariance of S-PASESC across gender and levels of education;(3) the latent factor mean difference between gender and levels of education;(4) the direct effects of self-efficacy on PA by different gender and education levels; and(5) the comparisons of the direct effects of self-efficacy on PA across gender and education levels.Methods: The participants were 5 th through 11 th grade public school students recruited from 7 cities located in different geographic regions of China. The final data include a total of 3003 participants(49.7% boys) who have completed the scales.Results: Confirmatory factor analysis(CFA) test supported the unidimensionality of S-PASESC. The S-PASESC is invariant across gender and 3 levels of education at both configural, full metric, and full scalar levels. Findings from latent mean comparisons showed that boys reported higher PA self-efficacy than girls. Students' perceived PA self-efficacy tend to decrease from elementary to high school. Finally, self-efficacy positively related to PA by groups of different gender and education levels and the relationship between self-efficacy and PA is stronger among middle school boys than girls.Conclusion: Findings suggest S-PASESC is a valid scale for measuring Chinese students' PA self-efficacy.

Antecedents and consequences of athlete's trust in the coach

Purpose： To assess the effects of trust in the coach on commitment to coach, willingness to cooperate, and perceived performance. Methods： Two hundred and fifteen members of competitive sports clubs responded to scales measuring coach characteristics of justice, benevolence, integrity, and competence; athlete＇s trust in the coach; commitment to coach; willingness to cooperate; and perceived performance. Results： Confirmatory factor analysis of data supported the measurement model. Perceptions of a coach＇s justice （β = 0.19, p 〈 0.05）, benevolence （β = 0.32, p 〈 0.05）, integrity （β= 0.14, p 〈 0.05）, and competence （β = 0.29, p 〈 0.05） each had a significant effect on athletes＇ trust, and they cumulatively accounted for 61% of the variance in trust. The structural equation modeling showed that trust had direct effects on commitment to coach （β = 0.77, p 〈 0.01）, willingness to cooperate （β= 0.79, p 〈 0.01 ）, and perceived performance （β = 0.51, p 〈 0.01）,. The hypothesized mediating effects of commitment to coach and willingness to cooperate were not supported. The model explained 26% of the variance in perceived performance. Conclusion： As trust in coach influences commitment to coach, willingness to cooperate, and perceived performance, coaches need to take effort to bolster their athletes＇ trust by being just and benevolent, and enhancing their integrity and competence.

Mechanotransduction of stem cells for tendon repair

Tendon is a mechanosensitive tissue that transmits force from muscle to bone.Physiological loading contributes to maintaining the homeostasis and adaptation of tendon,but aberrant loading may lead to injury or failed repair.It is shown that stem cells respond to mechanical loading and play an essential role in both acute and chronic injuries,as well as in tendon repair.In the process of mechanotransduction,mechanical loading is detected by mechanosensors that regulate cell differentiation and proliferation via several signaling pathways.In order to better understand the stem-cell response to mechanical stimulation and the potential mechanism of the tendon repair process,in this review,we summarize the source and role of endogenous and exogenous stem cells active in tendon repair,describe the mechanical response of stem cells,and finally,highlight the mechanotransduction process and underlying signaling pathways.