The Milan-Cortina Winter Olympics,in Italy,concluded on February 22,after 17 days of competitions that witnessed broad participation and historic breakthroughs.China-which fielded 126 athletes in 91 events across 15 d...The Milan-Cortina Winter Olympics,in Italy,concluded on February 22,after 17 days of competitions that witnessed broad participation and historic breakthroughs.China-which fielded 126 athletes in 91 events across 15 disciplines--sent its largest-ever delegation to an overseas Winter Olympics.展开更多
BACKGROUND In pediatric and adolescent athletes,there is a lack of understanding about the impact of factors such as race on the structural or cardiovascular adaptations in response to exercise which may unnecessarily...BACKGROUND In pediatric and adolescent athletes,there is a lack of understanding about the impact of factors such as race on the structural or cardiovascular adaptations in response to exercise which may unnecessarily disqualify athletes from the competitive sport.We hypothesized that race has an impact on cardiac adaptions in non-adult athletes.AIM To explore the racial disparity in electrocardiographic(ECG)and echocardiographic(ECHO)parameters in healthy adolescent athletes.METHODS A comprehensive electronic systematic literature search using MEDLINE database was performed from inception to September 20,2024.Inclusion criteria included randomized or observational cohort studies that recruited adolescent competitive athletes in any sport discipline and compared between the Black and White races with an age range of 12-18 years.RESULTS Of 723 records that were identified by the literature search,seven studies(n=5036)were included.The mean age was 13.0-18.0 years old with male predominance.Black athletes had significantly longer PR interval[mean difference(MD)=17.49 millisecond,95% CI:11.70-23.29]and shorter QRS complex duration(MD=-7.35 millisecond,95% CI:-9.17 to-5.53)and corrected QT interval(MD=-4.95 millisecond,95% CI:-7.69 to-2.22)than the White athletes.Black athletes were approximately four times more likely to have first-degree atrioventricular(AV)block,inverted T wave,ST-segment elevation,and left atrium(LA)enlargement than their White counterparts.In terms of ECHO parameters,Black athletes had significantly greater septal wall thickness(MD=0.85 mm,95% CI:0.62-1.07),posterior wall thickness(MD=1.07 mm,95% CI:0.36-1.78),relative wall thickness(MD=0.03,95%CI:0.001-0.06),maximal wall thickness(MD=1.05 mm,95%CI:0.28-1.83),and LA diameter(MD=1.64 mm,95%CI:0.16-3.12).CONCLUSION Race has an impact on the ECG and ECHO parameters that reflect cardiac adaptations in adolescent athletes.Black athletes tend to have an increased prevalence of distinct ECG changes such as first-degree AV block and T-wave inversions compared with their White counterparts.Despite having thicker septal and posterior walls,the overall prevalence of left ventricular hypertrophy did not differ between the races.展开更多
This study aimed to investigate the energy supply of athletes,who had a mild form of coronavirus infection(COVID-19)under cycling ergometric load(CEL)to substantiate the timing of recovery,as well as to determine the ...This study aimed to investigate the energy supply of athletes,who had a mild form of coronavirus infection(COVID-19)under cycling ergometric load(CEL)to substantiate the timing of recovery,as well as to determine the volume and intensity of physical activity.Eighty-seven athletes aged from 18 to 28 years old,involved in cyclic sports,were examined.Group I consisted of 52 athletes with COVID-19,and group Ⅱ consisted of 37 healthy self-isolating athletes.In addition to the comprehensive examination,the tested athletes underwent special examinations:the study of diagnostic material using methods of nucleic acid amplification,spirography and spiroergometry,electrocardiography(ECG),and CEL.The results of athletes from both groups did not differ significantly(p>0.5)in the 1^(st),2^(nd),and 3^(rd) examinations.The second examination revealed a discrepancy between functional reserves and the load performed,as evidenced by the difference in the recovery rate of most indicators,the results of the third examination in the long-term period(6 months)showed that the athletes of the first group did not have any violations of the parameters of the respiratory function(RF)and cardiovascular system at rest,after performing CEL,as well as in the recovery period.The results suggest that the full resumption of training loads and participation in competitions are possible only with the complete normalization of the functional state of the cardiorespiratory system.The most informative indicators are:minute ventilation(V E),heart rate(HR),oxygen pulse(OP),and coefficient of oxygen utilization(COU).展开更多
Background:Iron facilitates key biological functions underpinning sports performance,and up to 60%of female athletes experience iron deficiency.However,the effects of iron deficiency on sports performance in female at...Background:Iron facilitates key biological functions underpinning sports performance,and up to 60%of female athletes experience iron deficiency.However,the effects of iron deficiency on sports performance in female athletes is unclear,as are the degree of benefits of iron supplementation(FeSup).This study characterizes the effects of iron deficiency and FeSup on sports performance in high-level female athletes.Methods:Searches of the electronic databases MEDLINE,SPORTDiscus,Web of Science,Scopus,and CINAHL were performed in July 2023.Studies were included that evaluated the effects of iron deficiency or FeSup on sports performance in high-level(maximal oxygen uptake(VO2max)>45 mL/kg/min,or trained>5 h/week)iron deficient(ID)(serum ferritin(sFer)<40 mg/L)female athletes.Studies were assessed using a modified Downs and Black Quality Assessment Checklist.Results:A total of 23 studies comprising 669 athletes(age range:13-47 years)across 16 sports were included in the review.Iron deficiency negatively affects endurance performance by 3%-4%.However,endurance performance improved by 2%-20%when ID athletes were treated with 100 mg/day of elemental iron for up to 56 days via oral supplementation,or bi-daily via parenteral administration over 8-10 days.ID nonanemic athletes with low sFer stores may be predisposed to reduced maximal aerobic capacity.However,maximal aerobic capacity improved by 6%-15%following 16 mg/day-100 mg/day of elemental iron for 36-126 days.Isokinetic strength and anaerobic power performance may be impeded(-23%to+4%)among ID athletes,but the effect of FeSup on anaerobic power varied markedly(-5%to+9%)following 100 mg/day of elemental iron over 42-56 days,or 100 mg of elemental iron bi-daily over 8-10 days.The quality of studies was moderate(77%),ranging from low(57%)to high(100%).Moststudies(n=18)contained group sizes-20 athletes,thus limiting the likelihood of detecting significant effects(statistical power>0.80).Conclusion:High-level ID female athletes experience a negative impact on endurance performance,which can be improved by supplementing with»100 mg of elemental iron per day or bi-daily.The decrements in other performance parameters characterizing a range of sports coincide with the severity of iron deficiency.展开更多
Background:Psychological stress from academic and athletic demands adversely affects college athletes’mental health,the underlying mechanisms of this relationship remain insufficiently understood.Therefore,this study...Background:Psychological stress from academic and athletic demands adversely affects college athletes’mental health,the underlying mechanisms of this relationship remain insufficiently understood.Therefore,this study focuses on the Chinese college athletes and explores the relationship among mindfulness,stress coping,burnout,and mental health.Methods:The study used a sample of 500 student athletes from five higher sports colleges in China,collected data on various variables using standardized psychometric instruments,and analyzed the path relationships and mediating effects among the variables using structural equation modeling(SEM)and bootstrap methods.Results:Mindfulness significantly improved stress coping ability(β=0.721,p<0.001),and stress coping significantly improved mental health(β=0.606,p=0.027)and reduced burnout levels(β=−0.225,p<0.001).Burnout had a significant negative impact on mental health(β=−0.113,p=0.015).Mediation effect analysis revealed that stress coping played a mediating role between mindfulness and mental health(β=0.797,p<0.001),while the mediating effect of burnout was not statistically significant.When stress coping and burnout were considered simultaneously,they mediated the relationship between mindfulness and mental health(β=0.033,95%CI:[0.004,0.104],p=0.026).Conclusions:Mindfulness indirectly affects the mental health of college athletes by enhancing stress coping ability.The findings highlight the importance of integrating mindfulness training and stress coping strategies in sports training.Future studies should consider differences among sports to clarify the relationships between mindfulness,stress coping,burnout,and mental health.展开更多
Background:A greater prevalence of arrhythmias has been described in endurance athletes,but it remains unclear whether this risk persists after detraining.We aimed to evaluate the prevalence of arrhythmias and their r...Background:A greater prevalence of arrhythmias has been described in endurance athletes,but it remains unclear whether this risk persists after detraining.We aimed to evaluate the prevalence of arrhythmias and their relationship with cardiac remodeling in lifelong and retired master endurance athletes compared to non-athletic controls.Methods:We performed a cross-sectional analysis of observational studies that used echocardiography and cardiac magnetic resonance to detail cardiac structure and function,and Holter monitors to identify atrial and ventricular arrhythmias in 185 endurance athletes and 81 non-athletic controls aged≥40 years.Athletes were categorized as active lifelong(n=144)or retired(n=41)based on hours per week of high-intensity endurance exercise within 5 years of enrollment and validated by percentage of predicted maximal oxygen consumption(VO_(2max)).Athletes with overt cardiomyopathies,channelopathies,pre-excitation,and/or myocardial infarction were excluded.Results:Lifelong athletes(median age=55 years(interquartile range(IQR):46-62),79%male)were significantly fitter than retired athletes(median age=66 years(IQR:58-71),95%male)and controls(median age=53 years(IQR:48-60),96%male),respectively(predicted VO_(2max):131%±18%vs.99%±14%vs.98%±15%,p<0.001).Compared to controls,athletes in our cohort had a higher prevalence of atrial fibrillation((AF):32%vs.0%,p<0.001)and non-sustained ventricular tachycardia((NSVT):9%vs.1%,p=0.007).There was no difference in prevalence of any arrhythmia between lifelong and retired athletes.Lifelong athletes had larger ventricular volumes than retired athletes,who had ventricular volumes similar to controls(left ventricular end-diastolic volume indexed to body surface area(LVEDVi):101±20 m L/m^(2)vs.86±16 mL/m^(2)vs.94±18 mL/m^(2),p<0.001;right ventricular end-diastolic volume indexed to body surface area(RVEDVi):117±23 mL/m^(2)vs.101±19 mL/m^(2)vs.100±19 mL/m^(2),p<0.001).Athletes had more scar(40%vs.18%,p=0.002)and larger left atria(median volume=45m L/m^(2)(IQR:38-52)vs.31 mL/m^(2)(IQR:25-38),p<0.001)than controls,with no difference in atrial volumes and non-ischaemic scar between the athlete groups.Conclusion:Master endurance athletes have a higher prevalence of AF and NSVT than non-athletic controls.Whereas ventricular remodeling tends to reverse with detraining,the propensity to arrhythmias persists regardless of whether they are actively exercising or retired.展开更多
Background: Biological maturation refers to the progressive process through which individuals transition toward an adult state during growth and development. To address the challenges posed by differences in biologica...Background: Biological maturation refers to the progressive process through which individuals transition toward an adult state during growth and development. To address the challenges posed by differences in biological maturity and the limitations of existing testing methods, particularly in adolescent sports contexts, there is a pressing need for a non-invasive method that is convenient, accurate, and broadly applicable to monitor the biological maturity of adolescent athletes comprehensively. In response to this need, a maturity assessment method based on the smartphone application Maturo has been developed. This study evaluates the accuracy and validity of the Maturo software, an automated tool for estimating biological age and related maturation metrics.Methods: A sample of 103 actively training teenage athletes aged 9-17 years. The sample included 76 males(age = 11.74 ± 1.55 years, mean ±SD) and 27 females(age = 13.95 ± 1.40 years), all without medical conditions that might impact growth or development.Results: Compared to traditional expert evaluations, the intraclass correlation coefficients(ICCs) and Pearson correlation coefficients demonstrated reliable positive correlations and significant agreement between the Maturo software and expert methods across multiple metrics, such as biological age(ICC = 0.965, R = 0.97), corrected biological age(ICC = 0.973, R = 0.99), predicted adult height(ICC = 0.991, R = 0.99), and percentage of adult height achieved(ICC = 0.955, R = 0.97). The Bland-Altman plots provided additional evidence of the validity of the Maturo software estimations, showing low systematic error in most measures. The linear regression analysis produced excellent adjusted R2values: 0.95for biological age and 0.99 for anticipated adult height. The Maturo approach demonstrated a high level of dependability in classifying teenagers into groups based on their maturity status and timing. The κ coefficients of 0.93 for maturity status and 0.82 for maturity timing indicate a nearly perfect agreement with the expert technique.Conclusion: While the Maturo software's non-invasive nature, cost-effectiveness, and ease of use could make it a potential tool for regular monitoring of growth and maturation in young athletes, its promising results in assessing maturation should be interpreted with caution due to limitations such as sample size and demographic constraints. Further longitude research with larger and more diverse populations is needed to validate these preliminary findings and strengthen the evidence for its broader applicability.展开更多
1|Goalie Phenomenon The goalie phenomenon describes a group of health issues that may become apparent in children who prefer playing as goalkeepers.This preference might not only be about the excitement of the role bu...1|Goalie Phenomenon The goalie phenomenon describes a group of health issues that may become apparent in children who prefer playing as goalkeepers.This preference might not only be about the excitement of the role but also as a coping mechanism for underlying health issues that make continuous running and high physical exertion challenging.The term highlights how certain positions in sports can sometimes obscure or reveal hidden health conditions,particularly among young athletes[1–3].To our knowledge,this is the first paper to formally introduce the term“Goalie phenomenon”in the literature exploring exerciseinduced asthma and sports role preferences in children.展开更多
Purpose Athletes have presented a deficiency in relative energy in recent years,which calls for appropriate nutritional guid-ance based on the estimated energy requirement(EER)-the target amount of daily energy intake...Purpose Athletes have presented a deficiency in relative energy in recent years,which calls for appropriate nutritional guid-ance based on the estimated energy requirement(EER)-the target amount of daily energy intake(EI).The calculation of EER requires longitudinal physical activity level(PAL)data,which has received insufficient attention.Therefore,this study aimed to clarify the changes in PAL by training periodization using the doubly labeled water(DLW)method,combined with the current status of EI by competition characteristics.Methods The participants comprised four male sprint athletes and five male endurance athletes at the national level.The experimental periods were normal training(NT)and tapering training(TT)periods.PAL was measured using the DLW method,and EI was measured by the dietary record method.Results PAL of the sprint athletes in the NT periods was significantly higher than in TT periods.EI had no significant differ-ences between the two periods.PAL and EI of the endurance athletes had no significant differences beteen the two periods.Conclusions These findings indicated that in sprint athletes,different PAL was observed between the two periods,with the TT period suggesting a lower value than the NT period.In endurance athletes,it had similar PAL values between the two periods.This suggests that the degree of influence of the training period on PAL may vary depending on the athletic events.Furthermore,the EI was not adjusted for changes in PAL,and the participants observed the status of energy-deficient regardless of discipline or training period.展开更多
High-intensity interval training(HIIT),a highly efficient and distinctive exercise format,has sparked growing academic interest in sports performance training.This article synthesizes theoretical and applied evidence ...High-intensity interval training(HIIT),a highly efficient and distinctive exercise format,has sparked growing academic interest in sports performance training.This article synthesizes theoretical and applied evidence to analyze mechanisms of HIIT in neuromuscular activation,hormonal responses,muscle fiber adaptation,and metabolic pathway effects.It focuses on its effectiveness in enhancing explosive power,maximum strength,and strength endurance,while also examining the integration of HIIT with traditional resistance training,periodized programming,and personalized prescription.Scientific implementation of HIIT can effectively diversify or even replace conventional strength training,not only offering positive directional changes for strength development but also introducing innovative approaches to sports performance training practices.展开更多
Purpose This study aimed to describe athlete workload over the course of a four-year collegiate lacrosse career.Methods Workload was evaluated each day of training and games using global positioning system microtechno...Purpose This study aimed to describe athlete workload over the course of a four-year collegiate lacrosse career.Methods Workload was evaluated each day of training and games using global positioning system microtechnology.Total workload for each athlete was calculated for each season of each year for total distance,high-intensity distance,accelerations,decelerations,and sprints.Data were tabulated as absolute and relative workloads with absolute workload representing an individual athlete and relative workload representing that athlete’s percentage of team mean workload.Results The workload of the entire lacrosse team was collected over four years containing the full career of six athletes.Across the five workload variables analyzed,athletes either maintained a workload near team mean workload or demonstrated an increase in workload towards the end of their careers.Conclusion As careers progressed,the variation in athlete workload decreased,and athletes approached the team’s average workload.Microtechnology may be useful in monitoring athlete workload over the course of a career.展开更多
BACKGROUND Fixed esotropia in high myopia,characterized by irreversible inward ocular deviation and abduction limitation,presents unique therapeutic challenges for athletes requiring precise binocular coordination.The...BACKGROUND Fixed esotropia in high myopia,characterized by irreversible inward ocular deviation and abduction limitation,presents unique therapeutic challenges for athletes requiring precise binocular coordination.The combination of Yokoyama surgery and medial rectus muscle recession has been proposed as an advanced technique addresses both myopia-induced globe displacement and muscular imbalance offering potential advantages over conventional strabismus surgery in this population.AIM To investigate the effects of the modified Yokoyama surgery coupled with medial rectus muscle recession in restoring ocular motility and correcting esotropia among athletes with high myopia and fixed esotropia.METHODS A retrospective study analyzed 30 highly myopia athletes(57 eyes)with fixed esotropia treated at our hospital from January 2022 to April 2024.The participants were allocated into two groups based on the surgical method:The traditional group(n=15,29 eyes)received conventional strabismus surgery,and the combined group(n=15,28 eyes)underwent modified Yokoyama surgery in combination with medial rectus muscle recession.Eye movement improvement,esotropia alleviation,and complications were compared preoperatively and at 1,3,and 6 months post-treatment.RESULTS Both surgical groups exhibited similar baseline scores(traditional:-4.04±0.38 vs combined:-4.12±0.45,P>0.05),showing severe preoperative limitations in ocular motility.Following the intervention,the combined group achieved significantly better outcomes at both 1 month(combined:-2.25±0.28 vs traditional:-2.67±0.32)and 3 months(combined:-1.48±0.28 vs traditional:-1.76±0.43),with statistically significant improvements(P<0.05).However,by 6 months,no significant difference was observed between the two groups(combined:-0.93±0.13;traditional:-1.03±0.18;P>0.05).Prior to treatment,all patients in both groups exhibited a compensatory head posture(CHP).Following treatment,the incidence of CHP decreased to 6.67%in the combined group and 20.00%in the traditional group,both reductions being significant compared to pretreatment levels(P<0.05).Nevertheless,the difference in CHP incidence between the two groups after treatment was not significant(P>0.05).The rates of improvement in esotropia showed an increasing trend in both groups at 1 month(46.43%vs 34.48%),3 months(78.57%vs 51.728%),and 6 months(100.00%vs 89.66%)post-treatment.Notably,the combined group had a significantly higher improvement rate than the traditional group at the 3-month follow-up(P<0.05).No significant difference was observed in the esotropia improvement rates between the two groups at 1 and 6 months post-treatment(P>0.05).The combined group experienced slightly lower but not significant(combined group:0.00%vs traditional:3.45%)as opposed to the traditional group(3.45%;P>0.05).CONCLUSION The combination of modified Yokoyama surgery and medial rectus muscle recession provides effective and safe approach to improving in eye movement and esotropia in athletes with high myopia and fixed esotropia,offering reliable clinical benefits.展开更多
In order to help athletes optimize their performances in competitions while prevent overtraining and the risk of overuse injuries,it is important to develop science-based strategies for optimally designing training pr...In order to help athletes optimize their performances in competitions while prevent overtraining and the risk of overuse injuries,it is important to develop science-based strategies for optimally designing training programs.The purpose of the present study is to develop a novel method by the combined use of optimal control theory and a training-performance model for designing optimal training programs,with the hope of helping athletes achieve the best performance exactly on the competition day while properly manage training load during the training course for preventing overtraining.The training-performance model used in the proposed optimal control framework is a conceptual extension of the Banister impulse-response model that describes the dynamics of performance,training load(served as the control variable),fitness(the overall positive effects on performance),and fatigue(the overall negative effects on performance).The objective functional of the proposed optimal control framework is to maximize the fitness and minimize the fatigue on the competition day with the goal of maximizing the performance on the competition day while minimizing the cumulative training load during the training course.The Forward-Backward Sweep Method is used to solve the proposed optimal control framework to obtain the optimal solutions of performance,training load,fitness,and fatigue.The simulation results show that the performance on the competition day is higher while the cumulative training load during the training course is lower with using optimal control theory than those without,successfully showing the feasibility and benefits of using the proposed optimal control framework to design optimal training programs for helping athletes achieve the best performance exactly on the competition day while properly manage training load during the training course for preventing overtraining.The present feasibility study lays the foundation of the combined use of optimal control theory and training-performance models to design personalized optimal training programs in real applications in athletic training and sports science for helping athletes achieve the best performances in competitions while prevent overtraining and the risk of overuse injuries.展开更多
AIM：To compare visual efficiency,specifically accommodation,vergence,and oculomotor functions among athletes and non-athletes.METHODS：A cross-sectional study on sports vision screening was used to evaluate the visua...AIM：To compare visual efficiency,specifically accommodation,vergence,and oculomotor functions among athletes and non-athletes.METHODS：A cross-sectional study on sports vision screening was used to evaluate the visual skills of 214elementary students（107 athletes,107 non-athletes）,aged between 13 and 16y.The visual screening assessed visual parameters such as ocular motor alignment,accommodation,and vergence functions.RESULTS：Mean visual parameters were compared between age-group matched athletes（mean age14.82±0.98y）and non-athletes（mean age 15.00±1.04y）.The refractive errors of all participants were corrected to maximal attainable best corrected visual acuity of log MAR0.0.Accommodation function assessment evaluated amplitude of accommodation and accommodation facility.Vergence functions measured the near point of convergence,vergence facility,and distance fusional vergence at break and recovery point.Ocular motor alignment was not statistically significant between both groups.Athletes had a statistically significant amplitude of accommodation for both the right eye（t=2.30,P=0.02）and the left eye（t=1.99,P=0.05）.Conversely,non-athletes had better accommodation facility（t=-2.54,P=0.01）and nearpoint of convergence（t=4.39,P〈0.001）when compared to athletes.Vergence facility was found to be better among athletes（t=2.47,P=0.01）.Nevertheless,non-athletes were significantly better for both distance negative and positive fusional vergence.CONCLUSION：Although the findings are still inconclusive as to whether athletes had superior visual skills as compared to non-athletes,it remains important to identify and elucidate the key visual skills needed by athletes in order for them to achieve higher performance in their sports.展开更多
Purpose:The purpose of present study was to investigate the impact of sport experience on response inhibition and response re-engagement in expert badminton athletes during the stop-signal task and change-signal task....Purpose:The purpose of present study was to investigate the impact of sport experience on response inhibition and response re-engagement in expert badminton athletes during the stop-signal task and change-signal task.Methods:A total of 19 badminton athletes and 20 nonathletes performed both the stop-signal task and change-signal task.Reaction times(RTs)and event-related potentials were recorded and analyzed.Results:Behavioral results indicated that badminton athletes responded faster than nonathletes to go stimuli and to change signals,with faster change RTs and change-signal RTs,which take into consideration the variable stimulus onset time mean.During successful change trials in the change-signal task,the amplitudes of the event-related potential components N2 and P3 were smaller for badminton athletes than for nonathletes.Moreover,change-signal RTs and N2 amplitudes as well as change RTs and P3 amplitudes were significantly correlated in badminton athletes.A significant correlation was also found between the amplitude of the event-related potential component N1 and response accuracy to change signals in badminton athletes.Conclusion:Moderation of brain cortical activity in badminton athletes was more associated with their ability to rapidly inhibit a planned movement and re-engage with a new movement compared with nonathletes.The superior inhibitory control and more efficient neural mechanisms in badminton athletes compared with nonathletes might be a result of badminton athletes’ professional training experience.展开更多
In order to investigate the feasibility of serum creatine kinase （CK） and blood urea nitrogen （BUN） in monitoring pre-competition training of badminton athletes, the pre-competition training load of 20 badminton a...In order to investigate the feasibility of serum creatine kinase （CK） and blood urea nitrogen （BUN） in monitoring pre-competition training of badminton athletes, the pre-competition training load of 20 badminton athletes was studied, and serum CK and BUN were determined before, immediate and next morning after training. The results showed that after intensive training for one week, serum CK levels were significantly increased by 57.53 mmol/L （P〈0.05）. After regulation of the training intensity, average serum CK levels were increased by 21.79 mmol/L （P〈0.05）. BUN contents were increased by 0.83 mmol/L on average with the difference being not significant （P〉0.05）. After intermittent training, there was significant difference in the average increased levels of serum CK in athletes （P〈0.05）. There was significant difference before and after regulation of training （P〈0.05）. The increased levels of BUN were 0.78 mmol/L without significant difference （P〉0.05）. It was concluded that serum CK was one of the biochemical indicators monitoring the training load sensitivity of badminton athletes, but BUN was of little value in monitoring the training load. Both serum CK and BUN recovered slowly after one-week intensive training and intermittent training, suggesting the metabolic mechanism of human body in training needs further study.展开更多
AIM:To analyze stress fractures in athletes based on experience from our sports medicine clinic.METHODS:We investigated the association between stress fractures and age,sex,sports level,sports activity,and skeletal si...AIM:To analyze stress fractures in athletes based on experience from our sports medicine clinic.METHODS:We investigated the association between stress fractures and age,sex,sports level,sports activity,and skeletal site in athletes seen at our sports medicine clinic between September 1991 and April 2009.Stress fractures of the pars interarticularis were excluded from this analysis.RESULTS:During this period(18 years and 8 mo),14276 patients(9215 males and 5061 females)consulted our clinic because of sports-related injuries,and 263 patients(1.8%)[171 males(1.9%)and 92 females(1.8%)]sustained stress fractures.The average age of the patients with stress fractures was 20.2 years(range 10-46 years);112 patients(42.6%)were 15-19 years of age and 90(34.2%)were 20-24 years of age.Altogether,90 patients(34.2%)were active at a high recreational level and 173(65.8%)at a competitive level.The highest proportion of stress fractures was seen in basketball athletes(21.3%),followed by baseball(13.7%),track and field(11.4%),rowing(9.5%),soccer(8.4%),aerobics(5.3%),and classical ballet(4.9%).The most common sites of stress fractures in these patients were the tibia(44.1%),followed by the rib(14.1%),metatarsal bone(12.9%),ulnar olecranon(8.7%)and pelvis(8.4%).The sites of the stress fractures varied from sport to sport.The ulnar olecranon was the most common stress fracture site in baseball players,and the rib was the most common in rowers.Basketball and classical ballet athletes predominantly sustained stress fractures of the tibia and metatarsal bone.Track and field and soccer athletes predominantly sustained stress fractures of the tibia and pubic bone.Aerobics athletes predominantly sustained stress fractures of the tibia.Middle and long distance female runners who sustained multiple stress fractures had the female athlete triad.CONCLUSION:The results of this analysis showed that stress fractures were seen in high-level young athletes,with similar proportions for males and females,and that particular sports were associated with specific sites for stress fractures.Middle and long distance female runners who suffered from multiple stress fractures had the female athlete triad.展开更多
Background:Team-sport players have a particularly high injury risk.Although female sex is considered a risk factor,it is still unknown whether female and male team-sport players,in fact,differ in their injury rates.We...Background:Team-sport players have a particularly high injury risk.Although female sex is considered a risk factor,it is still unknown whether female and male team-sport players,in fact,differ in their injury rates.We aimed to compare injury rates between female and male players by systematically reviewing and meta-analyzing injury surveillance studies of both sexes in order to evaluate sex-specific differences in team-sport injuries.Methods:Studies that prospectively collected injury data for high-level female and male players(age≥16 years)in basketball,field hockey,football(soccer),handball,rugby(union and sevens),and volleyball were included.Two reviewers(AZ and ALR)independently assessed study quality and extracted data for overall,match,training,and severe injuries(>28 days’time loss)as well as data regarding injury locations and types.Incidence rate ratios(IRRs)were pooled in a meta-analysis,and meta-regression analysis was performed when 10 or more studies were available.Results:Of 20 studies,9 studies reported injury data from football,3 studies from rugby,3 studies from handball,1 study from basketball,1 study from field hockey,2 studies from volleyball,and 1 study from basketball and field hockey.For overall injuries,the pooled IRR=0.86(95%confidence interval(95%CI):0.76-0.98)indicated significantly more injuries in male than in female players.For injury location,the pooled IRR showed higher injury rates in male athletes than in female athletes for upper extremity,hip/groin,thigh,ande foot injuries.Female players had a significantly higher rate of anterior cruciate ligament injuries(IRR=2.15,95%CI:1.27-3.62)than male players.No significant sex-specific differences in IRR were found for match,training,severe injuries,concussions,or ankle sprains.Conclusion:Our meta-analysis provides evidence for sex-specific differences in the injury rates in team sports.Further epidemiological studies including both sexes in sports other than football are needed in order to strengthen the evidence.展开更多
Purpose： The present study aimed to examine the effect of static stretching （SS） and a sport-specific dynamic stretching （DS） session at two specific post-stretch time intervals in highly trained female athletes ...Purpose： The present study aimed to examine the effect of static stretching （SS） and a sport-specific dynamic stretching （DS） session at two specific post-stretch time intervals in highly trained female athletes （age 19.90 ± 1.60 years; height 1.80 ±0.06 m; mass 76.87 ± 9.95 kg） on kinetic parameters of peak force, time-to-takeoff, and rate of force development. Methods： The data were collected over 3 days （randomized within subject design with control session）. Following each stretch session （SS vs. DS vs. control） of equal duration （7 min total： 30 s per targeted muscle group） participants performed countermovement jumping on a force platform at 1 and 15 rain after stretching. Results： The DS session significantly improved upon kinetic variables of rate of force development, peak force, and time-to-takeoffrelative to SS at 1 min after stretching. No significant effect was found at 15 min. Conclusion： Together these findings suggest that when training and competing to jump quickly and maximally the female athlete should incorporate DS instead of SS as part of their pre-competition warm-up, but conduct performance within 15 min of their warm-up to elicit maximal gains展开更多
Jones type fifth metatarsal fracture is a common occurrence among athletes at all levels.These fractures may occur due to several mechanisms,but inversions and twisting injuries are considered some of the leading caus...Jones type fifth metatarsal fracture is a common occurrence among athletes at all levels.These fractures may occur due to several mechanisms,but inversions and twisting injuries are considered some of the leading causes in sports.However,while Jones fracture incidences are frequent in the sporting world,there is still a lack of consensus on how such fractures should be effectively managed.There are numerous treatment options for patients with fifth metatarsal Jones fractures.The role of nonoperative treatment remains controversial,with concerns about delayed union and nonunion.Surgical stabilization of metatarsal Jones fractures is therefore often recommended for athletes,as it is often associated with a low number of complications and a higher rate of union than nonoperative management.This review will focus on literature regarding the prevalence of Jones type fifth metatarsal fracture,alongside the efficacy of both conservative and surgical treatment within this population.展开更多
文摘The Milan-Cortina Winter Olympics,in Italy,concluded on February 22,after 17 days of competitions that witnessed broad participation and historic breakthroughs.China-which fielded 126 athletes in 91 events across 15 disciplines--sent its largest-ever delegation to an overseas Winter Olympics.
文摘BACKGROUND In pediatric and adolescent athletes,there is a lack of understanding about the impact of factors such as race on the structural or cardiovascular adaptations in response to exercise which may unnecessarily disqualify athletes from the competitive sport.We hypothesized that race has an impact on cardiac adaptions in non-adult athletes.AIM To explore the racial disparity in electrocardiographic(ECG)and echocardiographic(ECHO)parameters in healthy adolescent athletes.METHODS A comprehensive electronic systematic literature search using MEDLINE database was performed from inception to September 20,2024.Inclusion criteria included randomized or observational cohort studies that recruited adolescent competitive athletes in any sport discipline and compared between the Black and White races with an age range of 12-18 years.RESULTS Of 723 records that were identified by the literature search,seven studies(n=5036)were included.The mean age was 13.0-18.0 years old with male predominance.Black athletes had significantly longer PR interval[mean difference(MD)=17.49 millisecond,95% CI:11.70-23.29]and shorter QRS complex duration(MD=-7.35 millisecond,95% CI:-9.17 to-5.53)and corrected QT interval(MD=-4.95 millisecond,95% CI:-7.69 to-2.22)than the White athletes.Black athletes were approximately four times more likely to have first-degree atrioventricular(AV)block,inverted T wave,ST-segment elevation,and left atrium(LA)enlargement than their White counterparts.In terms of ECHO parameters,Black athletes had significantly greater septal wall thickness(MD=0.85 mm,95% CI:0.62-1.07),posterior wall thickness(MD=1.07 mm,95% CI:0.36-1.78),relative wall thickness(MD=0.03,95%CI:0.001-0.06),maximal wall thickness(MD=1.05 mm,95%CI:0.28-1.83),and LA diameter(MD=1.64 mm,95%CI:0.16-3.12).CONCLUSION Race has an impact on the ECG and ECHO parameters that reflect cardiac adaptations in adolescent athletes.Black athletes tend to have an increased prevalence of distinct ECG changes such as first-degree AV block and T-wave inversions compared with their White counterparts.Despite having thicker septal and posterior walls,the overall prevalence of left ventricular hypertrophy did not differ between the races.
文摘This study aimed to investigate the energy supply of athletes,who had a mild form of coronavirus infection(COVID-19)under cycling ergometric load(CEL)to substantiate the timing of recovery,as well as to determine the volume and intensity of physical activity.Eighty-seven athletes aged from 18 to 28 years old,involved in cyclic sports,were examined.Group I consisted of 52 athletes with COVID-19,and group Ⅱ consisted of 37 healthy self-isolating athletes.In addition to the comprehensive examination,the tested athletes underwent special examinations:the study of diagnostic material using methods of nucleic acid amplification,spirography and spiroergometry,electrocardiography(ECG),and CEL.The results of athletes from both groups did not differ significantly(p>0.5)in the 1^(st),2^(nd),and 3^(rd) examinations.The second examination revealed a discrepancy between functional reserves and the load performed,as evidenced by the difference in the recovery rate of most indicators,the results of the third examination in the long-term period(6 months)showed that the athletes of the first group did not have any violations of the parameters of the respiratory function(RF)and cardiovascular system at rest,after performing CEL,as well as in the recovery period.The results suggest that the full resumption of training loads and participation in competitions are possible only with the complete normalization of the functional state of the cardiorespiratory system.The most informative indicators are:minute ventilation(V E),heart rate(HR),oxygen pulse(OP),and coefficient of oxygen utilization(COU).
文摘Background:Iron facilitates key biological functions underpinning sports performance,and up to 60%of female athletes experience iron deficiency.However,the effects of iron deficiency on sports performance in female athletes is unclear,as are the degree of benefits of iron supplementation(FeSup).This study characterizes the effects of iron deficiency and FeSup on sports performance in high-level female athletes.Methods:Searches of the electronic databases MEDLINE,SPORTDiscus,Web of Science,Scopus,and CINAHL were performed in July 2023.Studies were included that evaluated the effects of iron deficiency or FeSup on sports performance in high-level(maximal oxygen uptake(VO2max)>45 mL/kg/min,or trained>5 h/week)iron deficient(ID)(serum ferritin(sFer)<40 mg/L)female athletes.Studies were assessed using a modified Downs and Black Quality Assessment Checklist.Results:A total of 23 studies comprising 669 athletes(age range:13-47 years)across 16 sports were included in the review.Iron deficiency negatively affects endurance performance by 3%-4%.However,endurance performance improved by 2%-20%when ID athletes were treated with 100 mg/day of elemental iron for up to 56 days via oral supplementation,or bi-daily via parenteral administration over 8-10 days.ID nonanemic athletes with low sFer stores may be predisposed to reduced maximal aerobic capacity.However,maximal aerobic capacity improved by 6%-15%following 16 mg/day-100 mg/day of elemental iron for 36-126 days.Isokinetic strength and anaerobic power performance may be impeded(-23%to+4%)among ID athletes,but the effect of FeSup on anaerobic power varied markedly(-5%to+9%)following 100 mg/day of elemental iron over 42-56 days,or 100 mg of elemental iron bi-daily over 8-10 days.The quality of studies was moderate(77%),ranging from low(57%)to high(100%).Moststudies(n=18)contained group sizes-20 athletes,thus limiting the likelihood of detecting significant effects(statistical power>0.80).Conclusion:High-level ID female athletes experience a negative impact on endurance performance,which can be improved by supplementing with»100 mg of elemental iron per day or bi-daily.The decrements in other performance parameters characterizing a range of sports coincide with the severity of iron deficiency.
文摘Background:Psychological stress from academic and athletic demands adversely affects college athletes’mental health,the underlying mechanisms of this relationship remain insufficiently understood.Therefore,this study focuses on the Chinese college athletes and explores the relationship among mindfulness,stress coping,burnout,and mental health.Methods:The study used a sample of 500 student athletes from five higher sports colleges in China,collected data on various variables using standardized psychometric instruments,and analyzed the path relationships and mediating effects among the variables using structural equation modeling(SEM)and bootstrap methods.Results:Mindfulness significantly improved stress coping ability(β=0.721,p<0.001),and stress coping significantly improved mental health(β=0.606,p=0.027)and reduced burnout levels(β=−0.225,p<0.001).Burnout had a significant negative impact on mental health(β=−0.113,p=0.015).Mediation effect analysis revealed that stress coping played a mediating role between mindfulness and mental health(β=0.797,p<0.001),while the mediating effect of burnout was not statistically significant.When stress coping and burnout were considered simultaneously,they mediated the relationship between mindfulness and mental health(β=0.033,95%CI:[0.004,0.104],p=0.026).Conclusions:Mindfulness indirectly affects the mental health of college athletes by enhancing stress coping ability.The findings highlight the importance of integrating mindfulness training and stress coping strategies in sports training.Future studies should consider differences among sports to clarify the relationships between mindfulness,stress coping,burnout,and mental health.
基金funded by the National Health and Medical Research Council of Australia(Grant No.APP1130353)supported by a Royal Australian College of Physicians Research Entry Scholarship(Grant No.2023RES00039)+4 种基金The National Health and Medical Research Council Postgraduate Scholarship(Grant No.2031119)a Heart Foundation PhD Scholarship(Grant No.107659)supported through an Australian Government Research Training Program Scholarshipsupported as a postdoctoral clinical researcher by the Fund for Scientific Research Flanderssupported by a National Health and Medical Research Council of Australia Investigator Grant(Grant No.APP 2027105)。
文摘Background:A greater prevalence of arrhythmias has been described in endurance athletes,but it remains unclear whether this risk persists after detraining.We aimed to evaluate the prevalence of arrhythmias and their relationship with cardiac remodeling in lifelong and retired master endurance athletes compared to non-athletic controls.Methods:We performed a cross-sectional analysis of observational studies that used echocardiography and cardiac magnetic resonance to detail cardiac structure and function,and Holter monitors to identify atrial and ventricular arrhythmias in 185 endurance athletes and 81 non-athletic controls aged≥40 years.Athletes were categorized as active lifelong(n=144)or retired(n=41)based on hours per week of high-intensity endurance exercise within 5 years of enrollment and validated by percentage of predicted maximal oxygen consumption(VO_(2max)).Athletes with overt cardiomyopathies,channelopathies,pre-excitation,and/or myocardial infarction were excluded.Results:Lifelong athletes(median age=55 years(interquartile range(IQR):46-62),79%male)were significantly fitter than retired athletes(median age=66 years(IQR:58-71),95%male)and controls(median age=53 years(IQR:48-60),96%male),respectively(predicted VO_(2max):131%±18%vs.99%±14%vs.98%±15%,p<0.001).Compared to controls,athletes in our cohort had a higher prevalence of atrial fibrillation((AF):32%vs.0%,p<0.001)and non-sustained ventricular tachycardia((NSVT):9%vs.1%,p=0.007).There was no difference in prevalence of any arrhythmia between lifelong and retired athletes.Lifelong athletes had larger ventricular volumes than retired athletes,who had ventricular volumes similar to controls(left ventricular end-diastolic volume indexed to body surface area(LVEDVi):101±20 m L/m^(2)vs.86±16 mL/m^(2)vs.94±18 mL/m^(2),p<0.001;right ventricular end-diastolic volume indexed to body surface area(RVEDVi):117±23 mL/m^(2)vs.101±19 mL/m^(2)vs.100±19 mL/m^(2),p<0.001).Athletes had more scar(40%vs.18%,p=0.002)and larger left atria(median volume=45m L/m^(2)(IQR:38-52)vs.31 mL/m^(2)(IQR:25-38),p<0.001)than controls,with no difference in atrial volumes and non-ischaemic scar between the athlete groups.Conclusion:Master endurance athletes have a higher prevalence of AF and NSVT than non-athletic controls.Whereas ventricular remodeling tends to reverse with detraining,the propensity to arrhythmias persists regardless of whether they are actively exercising or retired.
文摘Background: Biological maturation refers to the progressive process through which individuals transition toward an adult state during growth and development. To address the challenges posed by differences in biological maturity and the limitations of existing testing methods, particularly in adolescent sports contexts, there is a pressing need for a non-invasive method that is convenient, accurate, and broadly applicable to monitor the biological maturity of adolescent athletes comprehensively. In response to this need, a maturity assessment method based on the smartphone application Maturo has been developed. This study evaluates the accuracy and validity of the Maturo software, an automated tool for estimating biological age and related maturation metrics.Methods: A sample of 103 actively training teenage athletes aged 9-17 years. The sample included 76 males(age = 11.74 ± 1.55 years, mean ±SD) and 27 females(age = 13.95 ± 1.40 years), all without medical conditions that might impact growth or development.Results: Compared to traditional expert evaluations, the intraclass correlation coefficients(ICCs) and Pearson correlation coefficients demonstrated reliable positive correlations and significant agreement between the Maturo software and expert methods across multiple metrics, such as biological age(ICC = 0.965, R = 0.97), corrected biological age(ICC = 0.973, R = 0.99), predicted adult height(ICC = 0.991, R = 0.99), and percentage of adult height achieved(ICC = 0.955, R = 0.97). The Bland-Altman plots provided additional evidence of the validity of the Maturo software estimations, showing low systematic error in most measures. The linear regression analysis produced excellent adjusted R2values: 0.95for biological age and 0.99 for anticipated adult height. The Maturo approach demonstrated a high level of dependability in classifying teenagers into groups based on their maturity status and timing. The κ coefficients of 0.93 for maturity status and 0.82 for maturity timing indicate a nearly perfect agreement with the expert technique.Conclusion: While the Maturo software's non-invasive nature, cost-effectiveness, and ease of use could make it a potential tool for regular monitoring of growth and maturation in young athletes, its promising results in assessing maturation should be interpreted with caution due to limitations such as sample size and demographic constraints. Further longitude research with larger and more diverse populations is needed to validate these preliminary findings and strengthen the evidence for its broader applicability.
文摘1|Goalie Phenomenon The goalie phenomenon describes a group of health issues that may become apparent in children who prefer playing as goalkeepers.This preference might not only be about the excitement of the role but also as a coping mechanism for underlying health issues that make continuous running and high physical exertion challenging.The term highlights how certain positions in sports can sometimes obscure or reveal hidden health conditions,particularly among young athletes[1–3].To our knowledge,this is the first paper to formally introduce the term“Goalie phenomenon”in the literature exploring exerciseinduced asthma and sports role preferences in children.
基金supported by the Japan Society for the Promotion of Science,Grant Numbers JP 24700723,JP 17K13209.
文摘Purpose Athletes have presented a deficiency in relative energy in recent years,which calls for appropriate nutritional guid-ance based on the estimated energy requirement(EER)-the target amount of daily energy intake(EI).The calculation of EER requires longitudinal physical activity level(PAL)data,which has received insufficient attention.Therefore,this study aimed to clarify the changes in PAL by training periodization using the doubly labeled water(DLW)method,combined with the current status of EI by competition characteristics.Methods The participants comprised four male sprint athletes and five male endurance athletes at the national level.The experimental periods were normal training(NT)and tapering training(TT)periods.PAL was measured using the DLW method,and EI was measured by the dietary record method.Results PAL of the sprint athletes in the NT periods was significantly higher than in TT periods.EI had no significant differ-ences between the two periods.PAL and EI of the endurance athletes had no significant differences beteen the two periods.Conclusions These findings indicated that in sprint athletes,different PAL was observed between the two periods,with the TT period suggesting a lower value than the NT period.In endurance athletes,it had similar PAL values between the two periods.This suggests that the degree of influence of the training period on PAL may vary depending on the athletic events.Furthermore,the EI was not adjusted for changes in PAL,and the participants observed the status of energy-deficient regardless of discipline or training period.
文摘High-intensity interval training(HIIT),a highly efficient and distinctive exercise format,has sparked growing academic interest in sports performance training.This article synthesizes theoretical and applied evidence to analyze mechanisms of HIIT in neuromuscular activation,hormonal responses,muscle fiber adaptation,and metabolic pathway effects.It focuses on its effectiveness in enhancing explosive power,maximum strength,and strength endurance,while also examining the integration of HIIT with traditional resistance training,periodized programming,and personalized prescription.Scientific implementation of HIIT can effectively diversify or even replace conventional strength training,not only offering positive directional changes for strength development but also introducing innovative approaches to sports performance training practices.
文摘Purpose This study aimed to describe athlete workload over the course of a four-year collegiate lacrosse career.Methods Workload was evaluated each day of training and games using global positioning system microtechnology.Total workload for each athlete was calculated for each season of each year for total distance,high-intensity distance,accelerations,decelerations,and sprints.Data were tabulated as absolute and relative workloads with absolute workload representing an individual athlete and relative workload representing that athlete’s percentage of team mean workload.Results The workload of the entire lacrosse team was collected over four years containing the full career of six athletes.Across the five workload variables analyzed,athletes either maintained a workload near team mean workload or demonstrated an increase in workload towards the end of their careers.Conclusion As careers progressed,the variation in athlete workload decreased,and athletes approached the team’s average workload.Microtechnology may be useful in monitoring athlete workload over the course of a career.
文摘BACKGROUND Fixed esotropia in high myopia,characterized by irreversible inward ocular deviation and abduction limitation,presents unique therapeutic challenges for athletes requiring precise binocular coordination.The combination of Yokoyama surgery and medial rectus muscle recession has been proposed as an advanced technique addresses both myopia-induced globe displacement and muscular imbalance offering potential advantages over conventional strabismus surgery in this population.AIM To investigate the effects of the modified Yokoyama surgery coupled with medial rectus muscle recession in restoring ocular motility and correcting esotropia among athletes with high myopia and fixed esotropia.METHODS A retrospective study analyzed 30 highly myopia athletes(57 eyes)with fixed esotropia treated at our hospital from January 2022 to April 2024.The participants were allocated into two groups based on the surgical method:The traditional group(n=15,29 eyes)received conventional strabismus surgery,and the combined group(n=15,28 eyes)underwent modified Yokoyama surgery in combination with medial rectus muscle recession.Eye movement improvement,esotropia alleviation,and complications were compared preoperatively and at 1,3,and 6 months post-treatment.RESULTS Both surgical groups exhibited similar baseline scores(traditional:-4.04±0.38 vs combined:-4.12±0.45,P>0.05),showing severe preoperative limitations in ocular motility.Following the intervention,the combined group achieved significantly better outcomes at both 1 month(combined:-2.25±0.28 vs traditional:-2.67±0.32)and 3 months(combined:-1.48±0.28 vs traditional:-1.76±0.43),with statistically significant improvements(P<0.05).However,by 6 months,no significant difference was observed between the two groups(combined:-0.93±0.13;traditional:-1.03±0.18;P>0.05).Prior to treatment,all patients in both groups exhibited a compensatory head posture(CHP).Following treatment,the incidence of CHP decreased to 6.67%in the combined group and 20.00%in the traditional group,both reductions being significant compared to pretreatment levels(P<0.05).Nevertheless,the difference in CHP incidence between the two groups after treatment was not significant(P>0.05).The rates of improvement in esotropia showed an increasing trend in both groups at 1 month(46.43%vs 34.48%),3 months(78.57%vs 51.728%),and 6 months(100.00%vs 89.66%)post-treatment.Notably,the combined group had a significantly higher improvement rate than the traditional group at the 3-month follow-up(P<0.05).No significant difference was observed in the esotropia improvement rates between the two groups at 1 and 6 months post-treatment(P>0.05).The combined group experienced slightly lower but not significant(combined group:0.00%vs traditional:3.45%)as opposed to the traditional group(3.45%;P>0.05).CONCLUSION The combination of modified Yokoyama surgery and medial rectus muscle recession provides effective and safe approach to improving in eye movement and esotropia in athletes with high myopia and fixed esotropia,offering reliable clinical benefits.
基金funded by the National Science and Technology Council,grant number NSTC 113-2221-E-002-136-.
文摘In order to help athletes optimize their performances in competitions while prevent overtraining and the risk of overuse injuries,it is important to develop science-based strategies for optimally designing training programs.The purpose of the present study is to develop a novel method by the combined use of optimal control theory and a training-performance model for designing optimal training programs,with the hope of helping athletes achieve the best performance exactly on the competition day while properly manage training load during the training course for preventing overtraining.The training-performance model used in the proposed optimal control framework is a conceptual extension of the Banister impulse-response model that describes the dynamics of performance,training load(served as the control variable),fitness(the overall positive effects on performance),and fatigue(the overall negative effects on performance).The objective functional of the proposed optimal control framework is to maximize the fitness and minimize the fatigue on the competition day with the goal of maximizing the performance on the competition day while minimizing the cumulative training load during the training course.The Forward-Backward Sweep Method is used to solve the proposed optimal control framework to obtain the optimal solutions of performance,training load,fitness,and fatigue.The simulation results show that the performance on the competition day is higher while the cumulative training load during the training course is lower with using optimal control theory than those without,successfully showing the feasibility and benefits of using the proposed optimal control framework to design optimal training programs for helping athletes achieve the best performance exactly on the competition day while properly manage training load during the training course for preventing overtraining.The present feasibility study lays the foundation of the combined use of optimal control theory and training-performance models to design personalized optimal training programs in real applications in athletic training and sports science for helping athletes achieve the best performances in competitions while prevent overtraining and the risk of overuse injuries.
基金Supported by the Ministry of Higher Education Malaysia Sports Grant[No.KPT.N.660-7 Jld 7(3)]UKM Research Code NN-2013-069
文摘AIM：To compare visual efficiency,specifically accommodation,vergence,and oculomotor functions among athletes and non-athletes.METHODS：A cross-sectional study on sports vision screening was used to evaluate the visual skills of 214elementary students（107 athletes,107 non-athletes）,aged between 13 and 16y.The visual screening assessed visual parameters such as ocular motor alignment,accommodation,and vergence functions.RESULTS：Mean visual parameters were compared between age-group matched athletes（mean age14.82±0.98y）and non-athletes（mean age 15.00±1.04y）.The refractive errors of all participants were corrected to maximal attainable best corrected visual acuity of log MAR0.0.Accommodation function assessment evaluated amplitude of accommodation and accommodation facility.Vergence functions measured the near point of convergence,vergence facility,and distance fusional vergence at break and recovery point.Ocular motor alignment was not statistically significant between both groups.Athletes had a statistically significant amplitude of accommodation for both the right eye（t=2.30,P=0.02）and the left eye（t=1.99,P=0.05）.Conversely,non-athletes had better accommodation facility（t=-2.54,P=0.01）and nearpoint of convergence（t=4.39,P〈0.001）when compared to athletes.Vergence facility was found to be better among athletes（t=2.47,P=0.01）.Nevertheless,non-athletes were significantly better for both distance negative and positive fusional vergence.CONCLUSION：Although the findings are still inconclusive as to whether athletes had superior visual skills as compared to non-athletes,it remains important to identify and elucidate the key visual skills needed by athletes in order for them to achieve higher performance in their sports.
基金the Natural Science Foundation of China (31571151,31700985)the Scientific and Technological Commission of Shanghai(17080503100)
文摘Purpose:The purpose of present study was to investigate the impact of sport experience on response inhibition and response re-engagement in expert badminton athletes during the stop-signal task and change-signal task.Methods:A total of 19 badminton athletes and 20 nonathletes performed both the stop-signal task and change-signal task.Reaction times(RTs)and event-related potentials were recorded and analyzed.Results:Behavioral results indicated that badminton athletes responded faster than nonathletes to go stimuli and to change signals,with faster change RTs and change-signal RTs,which take into consideration the variable stimulus onset time mean.During successful change trials in the change-signal task,the amplitudes of the event-related potential components N2 and P3 were smaller for badminton athletes than for nonathletes.Moreover,change-signal RTs and N2 amplitudes as well as change RTs and P3 amplitudes were significantly correlated in badminton athletes.A significant correlation was also found between the amplitude of the event-related potential component N1 and response accuracy to change signals in badminton athletes.Conclusion:Moderation of brain cortical activity in badminton athletes was more associated with their ability to rapidly inhibit a planned movement and re-engage with a new movement compared with nonathletes.The superior inhibitory control and more efficient neural mechanisms in badminton athletes compared with nonathletes might be a result of badminton athletes’ professional training experience.
文摘In order to investigate the feasibility of serum creatine kinase （CK） and blood urea nitrogen （BUN） in monitoring pre-competition training of badminton athletes, the pre-competition training load of 20 badminton athletes was studied, and serum CK and BUN were determined before, immediate and next morning after training. The results showed that after intensive training for one week, serum CK levels were significantly increased by 57.53 mmol/L （P〈0.05）. After regulation of the training intensity, average serum CK levels were increased by 21.79 mmol/L （P〈0.05）. BUN contents were increased by 0.83 mmol/L on average with the difference being not significant （P〉0.05）. After intermittent training, there was significant difference in the average increased levels of serum CK in athletes （P〈0.05）. There was significant difference before and after regulation of training （P〈0.05）. The increased levels of BUN were 0.78 mmol/L without significant difference （P〉0.05）. It was concluded that serum CK was one of the biochemical indicators monitoring the training load sensitivity of badminton athletes, but BUN was of little value in monitoring the training load. Both serum CK and BUN recovered slowly after one-week intensive training and intermittent training, suggesting the metabolic mechanism of human body in training needs further study.
文摘AIM:To analyze stress fractures in athletes based on experience from our sports medicine clinic.METHODS:We investigated the association between stress fractures and age,sex,sports level,sports activity,and skeletal site in athletes seen at our sports medicine clinic between September 1991 and April 2009.Stress fractures of the pars interarticularis were excluded from this analysis.RESULTS:During this period(18 years and 8 mo),14276 patients(9215 males and 5061 females)consulted our clinic because of sports-related injuries,and 263 patients(1.8%)[171 males(1.9%)and 92 females(1.8%)]sustained stress fractures.The average age of the patients with stress fractures was 20.2 years(range 10-46 years);112 patients(42.6%)were 15-19 years of age and 90(34.2%)were 20-24 years of age.Altogether,90 patients(34.2%)were active at a high recreational level and 173(65.8%)at a competitive level.The highest proportion of stress fractures was seen in basketball athletes(21.3%),followed by baseball(13.7%),track and field(11.4%),rowing(9.5%),soccer(8.4%),aerobics(5.3%),and classical ballet(4.9%).The most common sites of stress fractures in these patients were the tibia(44.1%),followed by the rib(14.1%),metatarsal bone(12.9%),ulnar olecranon(8.7%)and pelvis(8.4%).The sites of the stress fractures varied from sport to sport.The ulnar olecranon was the most common stress fracture site in baseball players,and the rib was the most common in rowers.Basketball and classical ballet athletes predominantly sustained stress fractures of the tibia and metatarsal bone.Track and field and soccer athletes predominantly sustained stress fractures of the tibia and pubic bone.Aerobics athletes predominantly sustained stress fractures of the tibia.Middle and long distance female runners who sustained multiple stress fractures had the female athlete triad.CONCLUSION:The results of this analysis showed that stress fractures were seen in high-level young athletes,with similar proportions for males and females,and that particular sports were associated with specific sites for stress fractures.Middle and long distance female runners who suffered from multiple stress fractures had the female athlete triad.
文摘Background:Team-sport players have a particularly high injury risk.Although female sex is considered a risk factor,it is still unknown whether female and male team-sport players,in fact,differ in their injury rates.We aimed to compare injury rates between female and male players by systematically reviewing and meta-analyzing injury surveillance studies of both sexes in order to evaluate sex-specific differences in team-sport injuries.Methods:Studies that prospectively collected injury data for high-level female and male players(age≥16 years)in basketball,field hockey,football(soccer),handball,rugby(union and sevens),and volleyball were included.Two reviewers(AZ and ALR)independently assessed study quality and extracted data for overall,match,training,and severe injuries(>28 days’time loss)as well as data regarding injury locations and types.Incidence rate ratios(IRRs)were pooled in a meta-analysis,and meta-regression analysis was performed when 10 or more studies were available.Results:Of 20 studies,9 studies reported injury data from football,3 studies from rugby,3 studies from handball,1 study from basketball,1 study from field hockey,2 studies from volleyball,and 1 study from basketball and field hockey.For overall injuries,the pooled IRR=0.86(95%confidence interval(95%CI):0.76-0.98)indicated significantly more injuries in male than in female players.For injury location,the pooled IRR showed higher injury rates in male athletes than in female athletes for upper extremity,hip/groin,thigh,ande foot injuries.Female players had a significantly higher rate of anterior cruciate ligament injuries(IRR=2.15,95%CI:1.27-3.62)than male players.No significant sex-specific differences in IRR were found for match,training,severe injuries,concussions,or ankle sprains.Conclusion:Our meta-analysis provides evidence for sex-specific differences in the injury rates in team sports.Further epidemiological studies including both sexes in sports other than football are needed in order to strengthen the evidence.
文摘Purpose： The present study aimed to examine the effect of static stretching （SS） and a sport-specific dynamic stretching （DS） session at two specific post-stretch time intervals in highly trained female athletes （age 19.90 ± 1.60 years; height 1.80 ±0.06 m; mass 76.87 ± 9.95 kg） on kinetic parameters of peak force, time-to-takeoff, and rate of force development. Methods： The data were collected over 3 days （randomized within subject design with control session）. Following each stretch session （SS vs. DS vs. control） of equal duration （7 min total： 30 s per targeted muscle group） participants performed countermovement jumping on a force platform at 1 and 15 rain after stretching. Results： The DS session significantly improved upon kinetic variables of rate of force development, peak force, and time-to-takeoffrelative to SS at 1 min after stretching. No significant effect was found at 15 min. Conclusion： Together these findings suggest that when training and competing to jump quickly and maximally the female athlete should incorporate DS instead of SS as part of their pre-competition warm-up, but conduct performance within 15 min of their warm-up to elicit maximal gains
文摘Jones type fifth metatarsal fracture is a common occurrence among athletes at all levels.These fractures may occur due to several mechanisms,but inversions and twisting injuries are considered some of the leading causes in sports.However,while Jones fracture incidences are frequent in the sporting world,there is still a lack of consensus on how such fractures should be effectively managed.There are numerous treatment options for patients with fifth metatarsal Jones fractures.The role of nonoperative treatment remains controversial,with concerns about delayed union and nonunion.Surgical stabilization of metatarsal Jones fractures is therefore often recommended for athletes,as it is often associated with a low number of complications and a higher rate of union than nonoperative management.This review will focus on literature regarding the prevalence of Jones type fifth metatarsal fracture,alongside the efficacy of both conservative and surgical treatment within this population.
