Visual function,performance, and processing of basketball players vs. sedentary individuals     

Jesús Vera  Raimundo Jimnez  David Crdenas  Beatriz Redondo  Jos Antonio García 《运动与健康科学(英文)》2020,9(6):587-594

BackgroundAthletes tend to have better visuo-motor performance than do sedentary individuals. However, several basic visual-function and perceptual parameters remain unexplored to date. In this study, we investigated whether differences exist in visual function, performance, and processing between basketball players and individuals without a sport-involvement background.MethodsA total of 33 healthy men with no visual impairment or pathology were divided into 2 groups, depending on the involvement in sport (semi-professional basketball players and sedentary individuals). We tested their baseline heart-rate variability in the resting position apart from subjective questionnaires to determine their physical fitness level, and we checked their visual function, performance, and processing through an extended battery of optometric tests.ResultsThe 2 groups differed in resting heart-rate variability parameters (p < 0.001), confirming their dissimilarities in regular time practising sports per week. The basketball players showed a closer breakpoint and recovery nearpoint of convergence, a higher fusional-vergence rate, better discriminability halos, and better eye–hand coordination (all p values < 0.05).ConclusionThese results show evidence that athletes, basketball players in this case, exhibit better performance in several visual abilities in comparison to a group of individuals without sporting backgrounds, suggesting an improvement due to the systematic involvement of those skills during basketball practice.  相似文献   

Health-related fitness knowledge growth in middle school years: Individual- and school-level correlates     

Xihe Zhu  Justin A. Haegele  Haichun Sun 《运动与健康科学(英文)》2020,9(6):664-669

BackgroundHealth-related fitness knowledge (HRFK) has been an essential concept for many health and physical education programs. There has been limited understanding and longitudinal investigation on HRFK growth. This longitudinal study examined HRFK growth and its individual- and school-level correlates in middle school years under 1 curriculum condition: Five for Life.MethodsParticipants were 12,044 students from 47 middle schools. Data were collected at both individual/participant and school/institution levels. Individual-level variables included gender, grade, and HRFK test scores. School-level variables included percentage of students receiving free and reduced meals (FARM), student-to-faculty ratio for physical education, and school academic performance (SAP). We used hierarchical linear modeling to examine HRFK 3-year growth in relation to individual- and school-level correlates.ResultsThe average HRFK score at 6th grade for females was 42.81% ± 1.32%. The predicted HRFK growth was 17.06% ± 1.02% per year, holding other factors constant. A 1-standard deviation increase in FARM correlated with a 14.68%-point decrease in predicted test score (p = 0.02). A 1-standard deviation increase in SAP was associated with an 11.90%-point increase in HRFK score. Males had a significantly lower growth rate than females during the middle school years (0.78%/year, p = 0.02).ConclusionThe result showed that both individual- and school-level variables such as gender, FARM, and SAP influenced HRFK growth. Educators should heed gender differences in growth curves and recognize the correlates of school-level variables.  相似文献   

4周下肢间歇负压干预对优秀赛艇运动员心率变异性和儿茶酚胺的影响     

董徽徽  高炳宏 《上海体育学院学报》2020,(4):78-83

目的探讨下肢间歇负压干预对赛艇运动员心率变异性(HRV)相关指标和儿茶酚胺的影响。方法将国家赛艇队的14名运动员分为试验组和对照组,试验组运动员每周用间歇负压干预5 d,持续4周,对照组无其他干预方式。试验期间均对2组运动员进行HRV相关指标和儿茶酚胺的测试。结果试验前2组运动员各指标均无统计学差异。开始干预后2组的变化如下:①在时域指标中,试验组正常窦性R-R间期标准差(SDNN)在第3周时高于对照组(P<0.05)。②在频域指标中,试验组高频(HF)值在第2周和第3周时高于对照组(P<0.05),而其高频与低频比(LF/HF)在第1、3和4周时低于对照组(P<0.05)。③2组儿茶酚胺组内、组间比较均无统计学差异,但试验组儿茶酚胺下降程度比对照组高。结论4周的间歇负压干预对运动员自主神经系统功能的恢复有明显促进作用,对儿茶酚胺的分泌也具有抑制趋势;这有利于降低运动员心脏负荷,促进运动后的生理恢复。  相似文献   

The application of inertial measurement units and functional principal component analysis to evaluate movement in the forward 3½ pike somersault springboard dive     

Cherie Walker  John Warmenhoven  Peter J. Sinclair 《Sports biomechanics / International Society of Biomechanics in Sports》2019,18(2):146-162

Based on technological and analytical advances, the capability to more accurately and finitely examine biomechanical and skill characteristics of movement has improved. The purpose of this study was to use Inertial Measurement Units (IMUs) and Functional Principal Components Analysis (fPCA) to examine the role of movement variability (assessed via angular velocity), on 2 divers (1 international level; 1 national) performing the forward 3½ pike somersault dive. Analysis of angular velocity curves during ive-flight identified 5 fPCs, accounting for 96.5% of movement variability. The national diver’s scatter plots and standard deviation of fPC scores illustrated larger magnitudes of angular velocity variability across dive flight. For fPC1 and fPC3, magnitudes of SD variability were 282.6 and 201.5, respectively. The international diver illustrated more consistent angular velocity profiles, with clustering of fPCs scores (e.g., fPC1 & 3 = SD’s of 75.2 & 68.0). To account for lower variability in the international diver, the ability to better coordinate movement sequences and functionally utilise feedback in response to initiation of the somersault position is highlighted. Overall, findings highlight how both IMUs and fPCA can more holistically and finitely examine the biomechanical and skill characteristics of movement sequences with the capability to inform athlete development.  相似文献   

我国高尔夫球奥运选手与世界优秀选手一号木数据对比分析     

赵紫龙 《河北体育学院学报》2020,34(6):85-90

采用文献资料法、实地考察法、数理统计法和对比分析法，对我国奥运选手和世界优秀选手的一号木数据进行分析。发现，在实地考察的球洞中，世界优秀选手全四轮均使用一号木开球，而我国男子选手则是一号木、三号木交替开球，可能是由于对自身一号木开球技术不够自信；我国男子选手的一号木平均开球距离、上球道率较世界优秀选手均差距较大；我国女子选手的一号木平均开球距离与世界优秀选手较为接近，但上球道率有待提高。建议，男子选手加强开球距离和上球道率的训练，女子选手加强上球道率的训练；冯珊珊进一步提升开球距离；在比赛前要对场地进行多次熟悉，找到合适的开球策略。  相似文献   

Muscle force characteristics of male and female collegiate cross-country runners during overground running     

C. Nathan Vannatta  Thomas G. Almonroeder  Thomas W. Kernozek  Stacey Meardon 《Journal of sports sciences》2020,38(5):542-551

ABSTRACT

Males and females demonstrate unique running mechanics that may contribute to sex-related differences in common running related injuries. Understanding differences in muscle forces during running may inform intervention approaches, such as gait retraining addressing muscle force distribution. The purpose of this study was to compare muscle force characteristics and inter-trial variability between males and females during running. Twenty female and 14 male collegiate cross-country runners were examined. Three-dimensional kinetic and kinematic data were collected during overground running and used to estimate muscle forces via musculoskeletal modelling. Principle components analysis was used to capture the primary sources of variance from the muscle force waveforms. The magnitude of the forces for the hamstrings, gastrocnemius, and soleus muscles were higher across the majority of stance in male runners regardless of footstrike pattern. Males also demonstrated greater inter-trial variability in the timing of the peak gluteus maximus force and the magnitude of local peaks in the gastrocnemius force waveform. Male and female collegiate cross-country runners appear to employ unique lower extremity muscle force characteristics during overground running.  相似文献   

Initial Validity and Reliability of the Portuguese Borg Rating of Perceived Exertion 6-20 Scale     

Luana L. Cabral  Fábio Y. Nakamura  Joice M. F. Stefanello  Luiz C. V. Pessoa  Bruno P. C. Smirmaul  Gleber Pereira 《Measurement in physical education and exercise science》2020,24(2):103-114

ABSTRACT

The aims of this study were to perform the cross-cultural adaptation of the Borg Rating of Perceived Exertion (RPE) 6–20 Scale to Brazilian Portuguese language and to start testing its validity and reliability. After performing the cross-cultural adaptation of the Scale, concurrent and discriminative validity, and reliability were determined on a treadmill in young (18–30 years) and older adult women (60–75 years). Considering young and older adult women, RPE presented high and moderate positive correlation with heart rate and high and low positive correlation with oxygen consumption, respectively. Older adult women presented RPE (11 ± 2) significantly higher than young ones (8 ± 1) exercising at the same absolute intensity. Intraclass coefficient correlation was excellent for RPE to young and older adult women. The Scale presented concurrent validity only to young adult women, whereas it presented discriminative validity between such groups of women. Moreover, the scale is reliable to young and older adult women.  相似文献   

新疆和田地区碘缓释器评估报告     

谷云有  贾茜  李素梅 《中国科技信息》2007,(3):29-32

目的对新疆和田地区碘缓释器的使用进行系统评估;方法采用现场调查和实验室检测相结合的方法进行。结果土盐水使用碘缓释器组的水碘含量为23.1±49.0(mg/kg),明显高于土盐水未使用碘缓释器组的0.06±0.05(mg/kg);土盐水使用加碘器组尿碘中位数育龄妇女为125.3μg/L,儿童为134.5μg/L,均低于碘盐组但明显高于土盐水未使用碘缓释器组。有33.9%的育龄妇女和31.7%的儿童尿碘水平在100μg/L以下,25.4%的育龄妇女和29.3%的学龄儿童尿碘水平在300μg/L以上;土盐水使用加碘器组目标人群的甲状腺肿大率育龄妇女和学龄儿童分别为19.1和19.0%,,明显低于土盐水未使用碘缓释器组并接近碘盐组水平;土盐水使用加碘器组IDD知识知晓率在育龄妇女和儿童分别为72.9%和72.7%明显高于土盐水未使用碘缓释器组并接近碘盐组的水平。结论在和田地区使用碘缓释器作为预防和控制碘缺乏病的临时性替代措施是有效的。  相似文献   

在供应链管理环境下"走出去"企业的汇率风险决策分析   总被引：3，自引：0，他引：3  

马林  钟昌标 《中国软科学》2004,(7):93-96

"走出去"企业的经营面临越来越多的风险,汇率风险就是其中之一。在"走出去"企业的供应链管理中,实施怎样的供应链风险管理策略以降低供应链风险对企业整个供应链的影响,是我国众多"走出去"的企业亟待解决的一个重要问题。将汇率风险纳入企业供应链的决策模型中加以考虑,提高企业供应链的稳定性和运作效率是"走出去"企业供应链管理的关键。本文建立了基于汇率风险的企业供应链决策模型,并进行实证,为"走出去"企业的供应链管理决策提供参考。  相似文献   

中医治疗不孕的研究进展     

张云 《大众科技》2016,(5):96-97

随着"全面二胎"政策的开放,群众对不孕的关注不断提高。生活节奏的加快,不孕的患者也越来越多。中医药在治疗不孕症方面有着丰富的经验,且疗效优于西药,给患者带来的经济和精神压力较小,能有效增加患者的妊娠率,安全可靠。  相似文献