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1.
In order to examine the relationship of the athletes' impulsiveness,anger expression and the sportspersonship,368 athletes （male=256,female=102）were investigated to completed the questionnaire. The results suggested that there had a significant positive correlation between the athletes' impulsiveness and sportspersonship,there was significant difference on the sportspersonship between different impulsiveness level ;the cognitive impulsiveness and behavioral impulsiveness have significant positive prediction on the athletes' sportspersonship. There had significant relationship between the athletes' anger and the sportspersonship,there are significant sportspersonship difference between different anger level;the trait anger,state anger and anger out expression had significant prediction on the athletes' sportspersonship.  相似文献   

2.
Purpose:We aimed to perform a systematic review and meta-analysis of the effects of training to muscle failure or non-failure on muscular strength and hypertrophy.Methods:Meta-analyses of effect sizes(ESs)explored the effects of training to failure vs.non-failure on strength and hypertrophy.Subgroup meta-analyses explored potential moderating effects of variables such as training status(trained vs.untrained),training volume(volume equated vs.volume non-equated),body region(upper vs.lower),exercise selection(multi-vs.single-joint exercises(only for strength)),and study design(independent vs.dependent groups).Results:Fifteen studies were included in the review.All studies included young adults as participants.Meta-analysis indicated no significant difference between the training conditions for muscular strength(ES=-0.09,95%confidence interval(95%CI):-0.22 to 0.05)and for hypertrophy(ES=0.22,95%CI:-0.11 to 0.55).Subgroup analyses that stratified the studies according to body region,exercise selection,or study design showed no significant differences between training conditions.In studies that did not equate training volume between the groups,the analysis showed significant favoring of non-failure training on strength gains(ES=-0.32,95%CI:-0.57 to-0.07).In the subgroup analysis for resistance-trained individuals,the analysis showed a significant effect of training to failure for muscle hypertrophy(ES=0.15,95%CI:0.03-0.26).Conclusion:Training to muscle failure does not seem to be required for gains in strength and muscle size.However,training in this manner does not seem to have detrimental effects on these adaptations,either.More studies should be conducted among older adults and highly trained individuals to improve the generalizability of these findings.  相似文献   

3.
Background:One of the most life-threatening comorbidities in elderly cancer patients is cancer cachexia,which is characterized by the ongoing loss of skeletal muscular strength and mass and is also associated with aging.There is a lack of recommendations for optimal resistance training(RT) for those patients.The purpose of this study was to systematically review and quantify the effects of RT on muscular strength and hypertrophy in elderly cancer patients.Methods: Five electronic databases were searched(until January 2020) for studies that met the following criteria:(i) cancer patients aged>60 years;(ii) structured and supervised RT intervention for>6 weeks;and(iii) measured muscular strength and/or hypertrophy.Results:Thirteen studies(717 participants,average age=66 years) met the inclusion criteria.RT significantly increased muscular strength(mean effect size=0.87,95% confidence interval(95%CI):0.43-1.32,p <0.001) and did not significantly induce muscle hypertrophy(mean effect size=0.09,95%CI:-0.14 to 0.31,p=0.45).In subgroup analyses for muscle strength,higher weekly frequency was significantly associated with larger effect size.Egger’ s test showed no significant publication bias for the 2 outcomes.Conclusion:The results suggest that RT improves muscular strength but does not significantly induce muscle hypertrophy in elderly cancer patients.  相似文献   

4.
It is significant to investigate the landing load suffered by high-level athletes for evaluating the training effect and prevention of injury. Simulation can get the ground reaction force （GRF）that can't be gotten by force platforms,but the accuracy of data needs to be confirmed. The study investigated the similarity and characteristic values of landing force curves got by simulation and force platforms to verify the accuracy and reliability of Lifemod simulation. Results showed that the CMCs of GRF curves gotten by simulation and force platforms were all about 0.90 representing the high correlation. The difference value of maximum GRF was 1.4% of the maximum GRF got by force platforms,and the time difference of getting the maximum GRF was 0.002s.Conclusion：Accurate data matching the real value could be got by simulation. It is feasible and accurate to get the GRF of national level athletes in the training and match.  相似文献   

5.
Background:Accurate quantification of voluntary activation is important for understanding the extent of quadriceps dysfunction in individuals with anterior cruciate ligament reconstruction(ACLR).Voluntary activation has been quantified using both percent activation derived from the interpolated twitch technique and central activation ratio(CAR)derived from the burst superimposition technique,as well as by using different types of electrical stimulators and pulse train conditions.However,it is unclear how these parameters affect voluntary activation estimates in individuals with ACLR.This study was performed to fill this important knowledge gap in the anterior cruciate ligament literature.Methods:Quadriceps strength and voluntary activation were examined in 18 ACLR participants(12 quadriceps/patellartendon graft,6 hamstring tendon graft;time since ACLR:1.06±0.82 years,mean±SD)at 90°of knee flexion using 2 stimulators(Digitimer and Grass)and pulse train conditions(3-pulse and 10-pulse).Voluntary activation was quantified by calculating both CAR and percent activation.Results:Results indicated that voluntary activation was significantly overestimated by CAR when compared with percent activation(p<0.001).Voluntary activation estimates were not affected by pulse train conditions when using percent activation;however,3-pulse stimuli resulted in greater overestimation than 10-pulse stimuli when using CAR(p=0.003).Voluntary activation did not differ between stimulators(p>0.05);however,the Digitimer evoked greater torque at rest than the Grass(p<0.001).Conclusion:These results indicate that percent activation derived from the interpolated twitch technique provides superior estimates of voluntary activation than CAR derived from burst superimposition and is less affected by pulse train conditions or stimulators in individuals with ACLR.  相似文献   

6.
Background:In a sprint cross-country(XC)ski competition,the difference in recovery times separating the first and the second semi-final(SF)heats from the final(F)may affect performance.The aim of the current study was to compare the effects of longer vs.shorter recovery periods prescribed between the 3 knock-out races of a simulated sprint XC ski competition involving a prologue(P),quarter-final(QF),SF,and F.Methods:Eleven well-trained XC ski athletes completed 2 simulated sprint XC ski competitions on a treadmill involving 4×883-m roller-ski bouts at a 4°incline using the gear 3 ski-skating sub-technique.The first 3 bouts were completed at a fixed speed(PFIX,QFFIX,and SFFIX)corresponding to~96%of each individual’s previously determined maximal effort.The final bout was performed as a self-paced sprint time trial(FSTT).Test conditions differed by the time durations prescribed between the QFFIX,SFFIX,and FSTT,which simulated real-world XC ski competition conditions using maximum(MAX-REC)or minimum(MIN-REC)recovery periods.Results:The FSTT was completed 5.4±5.5 s faster(p=0.009)during MAX-REC(179.2±18.1 s)compared to MIN-REC(184.6±20.0 s),and this was linked to a significantly higher power output(p=0.010)and total metabolic rate(p=0.009).The pre FSTT blood lactate(BLa)concentration was significantly lower during MAX-REC compared to MIN-REC(2.5±0.8 mmol/L vs.3.6±1.6 mmol/L,respectively;p=0.027),and the pre-to-post FSTT increase in BLa was greater(8.8±2.1 mmol/L vs.7.1±2.3 mmol/L,respectively;p=0.024).No other differences for MAX-REC vs.MIN-REC reached significance(p>0.05).Conclusion:Performance in a group of well-trained XC skiers is negatively affected when recovery times between sprint heats are minimized which,in competition conditions,would occur when selecting the last QF heat.This result is combined with a higher pre-race BLa concentration and a reduced rise in BLa concentration under shorter recovery conditions.These findings may help inform decision making when XC skiers are faced with selecting a QF heat within a sprint competition.  相似文献   

7.
Purpose:This study aimed to determine the accuracy of a 4 split time modelling method to generate velocity-time and velocity-distance variables in elite male 100-m sprinters and subsequently to assess the roles of key sprint parameters with respect to 100-m sprint performance.Additionally,this study aimed to assess the differences between faster and slower sprinters in key sprint variables that have not been assessed in previous work.Methods:Velocity-time and velocity-distance curves were generated using a mono-exponential function from 4 split times for 82 male sprinters during major athletics competitions.Key race variables-maximum velocity,the acceleration time constant(τ),and percentage of velocity lost(vLoss)-were derived for each athlete.Athletes were divided into tertiles,based on 100-m time,with the first and third tertiles considered to be the faster and slower groups,respectively,to facilitate further analysis.Results:Modelled split times and velocities displayed excellent accuracy and close agreement with raw measures(range of mean bias was-0.2%to 0.2%,and range of intraclass correlation coefficients(ICCs)was 0.935 to 0.999)except for 10-m time(mean bias was 1.6%±1.3%,and the ICC was 0.600).The 100-m sprint performance time and all 20-m split times had a significant near-perfect negative correlation with maximum velocity(r≥-0.90)except for the 0 to 20-m split time,where a significantly large negative correlation was found(r=-0.57).The faster group had a significantly higher maximum velocity andτ(p<0.001),and no significant difference was found for vLoss(p=0.085).Conclusion:Coaches and researchers are encouraged to utilize the 4 split time method proposed in the current study to assess several key race variables that describe a sprinter’s performance capacities,which can be subsequently used to further inform training.  相似文献   

8.
licit self-esteem and explicit self-esteem of 34 university students were investigated,the results showed that there was a difference in implicit self-esteem and explicit self-esteem,but this difference was not significant.In second study,the implicit attitude and explicit attitude to doping and beverage of 45 elite university athletes were examined.The results showed that there was a slight difference between implicit attitude and explicit attitude to doping and beverage which had different social approval,but this difference was also not significant.The results of these two studies showed that the regulation of social approval to the relations between implicit cognition and  相似文献   

9.
Background:Participation in physical activity supports greater cardiorespiratory fitness(CRF),a correlate of cognitive control.However,the relationship between muscular fitness(MF)and cognitive control is less clear.The present study investigated the differential relationship of CRF and MF with cognitive control in older adolescents.Methods:This cross-sectional study involved students(1517 years old,n=541,43%female)from 20 secondary schools who completed tests of inhibition(modified flanker task),working memory(n-back task),CRF(Progressive Aerobic Cardiovascular Endurance Run),and MF(standing long jump and push-up test).Multilevel analyses tested the association between CRF or MF and cognitive outcomes while accounting for the influence of the other fitness variable and relevant demographic factors.Results:CRF predicted response accuracy during incongruent flanker trials,the condition requiring greater inhibition.For the working memory task,CRF predicted greater target accuracy and greater d’scores on the 1-back task,requiring lesser amounts of working memory.In the 2-back task,which requires greater amounts of working memory,CRF also predicted greater target and non-target accuracy and d’scores.Comparatively,MF did not predict any cognitive outcomes after adjustment for CRF.Conclusion:CRF was selectively related to better performance during task conditions that require greater amounts of inhibition and working memory.This finding suggests that CRF,but not MF,may benefit cognitive control in older adolescents.This selective influence of CRF on older adolescents’cognition highlights the value of aerobic physical activity.  相似文献   

10.
Background: Evidence shows an association between grip strength and health;however, grip strength cut-offs for the detection of metabolic syndrome(MetS) in Latin American populations are scarce. The purpose of this study was to determine cut-offs of normalized grip strength(NGS)for the detection of MetS in a large nonrepresentative sample of a collegiate student population from Colombia.Methods: A total of 1795 volunteers(61.4% female;age = 20.68 ± 3.10 years, mean ± SD), ranging between 18 and 30 years of age participated in the study. Strength was estimated using a handheld dynamometer and normalized to body mass(handgrip strength(kg)/body mass(kg)). Anthropometrics, serum lipids indices, blood pressure, and fasting plasma glucose were measured. Body composition was measured by bioelectrical impedance analysis. MetS was defined as including ≥3 of the 5 metabolic abnormalities according to the International Diabetes Federation definition. A metabolic risk score was computed from the following components: waist circumference, triglycerides, high-density lipoprotein cholesterol, glucose, and systolic and diastolic blood pressure.Results: Receiver operating curve analysis showed significant discriminatory accuracy of NGS in identifying the thresholds and risk categories.Lower strength was associated with increased prevalence of MetS. In males, weak, intermediate, and strong NGS values at these points were<0.466, 0.466-0.615, >0.615, respectively. In females, these cut-off points were <0.332, 0.332-0.437, >0.437, respectively.Conclusion: Our sex-specific cut-offs of NGS could be incorporated into a clinical setting for identifying college students at cardiometabolic disease risk.  相似文献   

11.
In order to provide to evaluate city community sports' public service in China with effective measurement tools and reliable basis so that the performance evaluation can carry out smoothly,develop urban community sports' public service satisfaction scale by using the following methods：questionnaire,mathematical statistics and logical analysis and the rest. Through combining the literature review with all kinds of experts in-depth interviews and the views and data of the half-open research,form 51 items of "initial scale";Through analyzing the project,and striving for CR,delete the 13 items,which cannot reach significant difference between high and low group（P>0.05）;By exploratory factor analysis,gradually remove the 6 items,which is out of conditions and its extracting common load is less than 0.4 and the common degree less than 0.2. When the five common elements,the satisfaction degree of the community sports facilities' service （F1）,the satisfaction degree of the community sports organization service （F2）,the satisfaction degree of community sports fitness guidance service（F3）,the satisfaction degree of community sports culture construction service（F4）,the satisfaction degree of the community sports running and management service（F5）,which the stable cumulative variance contribution rates' extracted characteristic value is greater than 1 ,can basically form the scale that owns 33 items,and finally make the supposing structure model out;Confirmatory factor analysis found that the supposing structure model is content with the sample data;Internal consistency reliability,repeated reliability,structure validity and content validity test show that the scale has good validity and the reliability is better;This scale is a good tool in measuring the community sports' public service satisfaction in a rich city.  相似文献   

12.
Background:Physical activity(PA)has substantial health benefits and is important in combatting chronic diseases,which have been associated with elevated levels of advanced glycation endproducts(AGEs).AGEs play a role in the aging process,and an association between PA and AGEs has been reported.We aimed to investigate the relationship between PA and AGE accumulation in a general population and in a population with chronic diseases.Methods:This large cross-sectional population study used data from adult participants in the LifeLines project,with participant information drawn from the LifeLines database as well data from patients with diabetes mellitus or renal and/or cardiovascular diseases.Tissue AGE accumulation was assessed non-invasively by skin-autofluorescence(SAF)using an AGE reader(DiagnOptics Technologies BV,Groningen,the Netherlands).PA was assessed using the short questionnaire to assess health-enhancing physical activity(SQUASH).Multivariate linear regression analyses were adjusted for age,body mass index,sex,and smoking status.Results:Data from 63,452 participants(general population n=59,177,chronic disease n=4275)were analyzed.The general population was significantly younger(43.58±11.77 years,mean±SD)and had significantly lower SAF(1.90±0.42 arbitrary units(AU))compared to the population with chronic disease(age:55.51±12.07 years;SAF:2.27±0.51 AU).In the group with chronic disease,more hours of moderate to vigorous physical activities per week were associated with lower SAF(β=-0.002,95%confidence interval(95%CI):-0.002 to-0.001).For the general population,there was no association between hours of moderate to vigorous activity and SAF(β=3.2×10-5,95%CI:0.000-0.001,p=0.742).However,there was an association in the general population between total hours of PA per week and SAF(β=4.2×10-4,95%CI:0.000-0.001,p<0.001),but this association was not found in the chronic disease population(β=-3.2×10-4,95%CI:-0.001 to 0.000,p=0.347).Conclusion:Our study demonstrates that an inverse relationship exists between PA and AGE accumulation in the population with chronic disease.More hours of moderate to vigorous activity is associated a significantly decreased SAF.More PA is associated a lower SAF,even after for the established predictors(age,body mass index,smoking status,and sex).Our findings could help to promote health and prolong longevity.  相似文献   

13.
Purpose:The present study aimed to systematically review and compare 2 femoral autograft fixation techniques,namely,interference screws and suture anchors,for isolated medial patellofemoral ligament reconstruction in patients with recurrent patellofemoral instability at mid-to long-term follow-up.Methods:A literature search was performed in September 2020.All studies reporting the outcomes of primary isolated medial patellofemoral ligament reconstruction for recurrent patellofemoral instability were considered for inclusion.Only studies reporting the type of femoral autograft fixation under examination were considered.Studies reporting data from patients with elevated tibial tuberosity-tibial groove,patella alta,and/or Dejour’s trochlear dysplasia types C and D,were not included.Only articles reporting data with a minimum follow-up period of 18 months were considered.Results:Data from 19 studies(615 patients)were retrieved.The overall age was 24.4±6.7 years(mean±SD).The mean follow-up was 46.5±20.9 months.There were 76 patients in the anchor group and 539 in the screw group.Comparability was found with regard to age and follow-up duration between the 2 study groups.There was comparability between the Kujala,Lysholm,and Tegner scores at baseline.At the last follow-up,no worthy differences were found in terms of mean Kujala(+2.1%;p=0.04),Lysholm(+1.7%;p=0.05),and Tegner(+15.8%;p=0.05)scores.Although complications occurred almost exclusively in the screw cohort,no statistically significant difference was found.Conclusion:Femoral autograft fixation through interference screws or suture anchors report similar clinical scores and rate of apprehension test,persistent joint instability,re-dislocations,and revisions.These results must be interpreted within the limitations of the present study.  相似文献   

14.
Background:Gross motor skills are postulated to have a bidirectional relationship with physical activity(PA);however,no study has tested this relationship before and after a summer break.The purpose of this study was to examine the bidirectional relationships between school PA and gross motor skills in children before and after a summer break.Methods:Participants were a sample of 440 children recruited from 3 low-income schools(age=8.9±1.2 years,mean±SD).PA was assessed as average school-day step counts using Yamax DigiWalker pedometers(Yamasa Tokei Keiki,Tokyo,Japan)worn for 5 consecutive school days.Gross motor skills were assessed using the Test for Gross Motor Development,3 rd edition.Data were collected at 2 timepoints:at the end of spring semester(T1)and at the beginning of the subsequent fall semester(T2).An age-and body mass index-adjusted cross-lagged model was employed to relate T1 school step counts with T2 gross motor skills and T1 gross motor skills with T2 school step counts.Results:T1 gross motor skills significantly predicted T2 school step counts(β=0.24,95%confidence interval(95%CI):0.08-0.40,p=0.003);however,Tl school step counts did not predict T2 gross motor skills(β=0.04,95%CI:-0.06 to 0.14,p=0.445).The model explained 35.4%and 15.9%of the variances of T2 gross motor skills and T2 school step counts,respectively.Additional analyses indicated that these relationships were driven primarily by ball skills.Conclusion:The relationship between gross motor skills and school PA was not bidirectional;however,higher gross motor skills,specifically ball skills,predicted higher school PA after a 3-month summer break.  相似文献   

15.
In this study,surface EMG signals from bilateral erector spine as well as kinematic variables of lumbar spine of 20 male adult subjects were recorded and analyzed synchronically during their performances of trunk flexion-extension with 7 different lift loads. The results showed that different lifting load has no effect on both inclination angle and flexion angle at the time of EMG-off or EMG-on ,and flexion relaxation phenomenon of erector spine either. With the increase of lifting load,the maximum low back moment,the low back moment at the time of EMG-off and that at the time of EMG-on be－ came significantly larger. In the load-sharing relationship,the passive tissue could not significantly get a compensation from muscular activation of erector spine,which is a highly risk situation of injury for passive tissues in low back area especially when lifting with a greater load.  相似文献   

16.
Background:One of the pathological hallmarks distinguishing Alzheimer’s disease from other dementias is the accumulation of amyloid beta(Aβ).Higher physical activity is associated with decreased dementia risk,and one potential path could be through Aβ levels modulation.We aimed to explore the relationship between physical activity and Aβ in middle-aged and older adults.Methods:A systematic search of PubMed,Web of Science,PsycINFO,Cochrane Central Register of Controlled Trials,and SPORTDiscus was...  相似文献   

17.
Background:Eccentric exercise increases muscle fascicle lengths;however,the mechanisms behind this adaptation are still unknown.This study aimed to determine whether biceps femoris long head(BFlh)fascicle length increases in response to 3 weeks of eccentric exercise training are the result of an in-series addition of sarcomeres within the muscle fibers.Methods:Ten recreationally active participants(age=27±3 years;mass=70±14 kg;height=174±9 cm;mean±SD)completed 3 weeks of Nordic hamstring exercise(NHE)training on a custom exercise device that was instrumented with load cells.We collected in vivo sarcomere and muscle fascicle images of the BFlh in 2 regions(central and distal)by using microendoscopy and 3 dimension ultrasonography.We then estimated sarcomere length,sarcomere number,and fascicle length before and after the training intervention.Results:Eccentric knee flexion strength increased after the training(15%;p<0.001;ηp2=0.75).Further,we found a significant increase in fascicle length(21%;p<0.001;ηp2=0.81)and sarcomere length(17%;p<0.001;ηp2=0.90)in the distal but not in the central portion of the muscle.The estimated number of sarcomeres in series did not change in either region.Conclusion:Fascicle length adaptations appear to be heterogeneous in the BFlh in response to 3 weeks of NHE training.An increase in sarcomere length,rather than the addition of sarcomeres in series,appears to underlie increases in fascicle length in the distal region of the BFlh.The mechanism driving regional increases in fascicle and sarcomere length remains unknown,but we speculate that it may be driven by regional changes in the pas sive tension of muscle or connective tis sue adaptations.  相似文献   

18.
Purpose:To investigate whether blood flow restriction(BFR) without concomitant exercise mitigated strength reduction and atrophy of thigh muscles in subjects under immobilization for lower limbs.Methods:The following databases were searched:PubMed,CINAHL,PEDro,Web of Science,Central,and Scopus.Results:The search identified 3 eligible studies,and the total sample in the identified studies consisted of 38 participants.Isokinetic and isometric torque of the knee flexors and extensors was examined in 2 studies.Cross-sectional area of thigh muscles was evaluated in 1 study,and thigh girth was measured in 2 studies.The BFR protocol was 5 sets of 5 min of occlusion and 3 min of free flow,twice daily for approximately 2 weeks.As a whole,the included studies indicate that BFR without exercise is able to minimize strength reduction and muscular atrophy after immobilization.It is crucial to emphasize,however,that the included studies showed a high risk of bias,especially regarding allocation concealment,blinding of outcome assessment,intention-to-treat analyses,and group similarity at baseline.Conclusion:Although potentially useful,the high risk of bias presented by original stodies limits the indication of BFR without concomitant exercise as an effective countermeasure against strength reduction and atrophy mediated by immobilization.  相似文献   

19.
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20.
Sports consumption is the important strength to promote economic development,so it is significant to protect sports consumer's rights and interests. Sports consumer should be defined to be the individual who purchase sports goods or sports service for sports life. It's very important to protect sports consumers' individual information right,safety right and the right of returning goods without reason,and the articles in the Consumers Protection Law amendment has been improved and will be significant in application. The Sports Law should be also amended accordingly ,and it's necessary to support the formation of public interest litigation in sports consumption field.  相似文献   

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