Validity and reliability of a linear positional transducer across commonly practised resistance training exercises     

Harry F. Dorrell  Joseph M. Moore  Mark F. Smith  Thomas I. Gee 《Journal of sports sciences》2019,37(1):67-73

This study investigated the validity and reliability of the GymAware PowerTool (GPT). Thirteen resistance trained participants completed three visits, consisting of three repetitions of free-weight back squat, bench press, deadlift (80% one repetition maximum), and countermovement jump. Bar displacement, peak and mean velocity, peak and mean force, and jump height were calculated using the GPT, a three-dimensional motion capture system (Motion Analysis Corporation; 150 Hz), and a force plate (Kistler; 1500 Hz). Least products regression were used to compare agreeability between devices. A within-trial one-way ANOVA, typical error (TE; %), and smallest worthwhile change (SWC) were used to assess reliability. Regression analysis resulted in R² values of >0.85 for all variables excluding deadlift mean velocity (R² = 0.54–0.69). Significant differences were observed between visits 3-2 for bench press bar displacement (0.395 ± 0.055 m; 0.383 ± 0.053 m), and deadlift bar displacement (0.557 ± 0.034 m; 0.568 ± 0.034 m). No other significant differences were found. Low to moderate TE (0.6–8.8%) were found for all variables, with SWC ranging 1.7–7.4%. The data provides evidence that the GPT can be used to measure kinetic and kinematic outputs, however, care should be taken when monitoring deadlift performance.  相似文献   

浅谈气步枪比赛中的节奏     

谢国卿 《体育科研》2003,24(4):41-42

通过对上海市天山中学部分运动员参加上海市第十二届运动会气枪比赛前后经过的回顾和分析,认为气步枪比赛中存在的一个节奏现象是影响运动员技术水平和心理状态的重要因素,也就是最终影响成绩的重要因素.  相似文献   

双重缺氧训练与5 km武装越野能力的关系研究     

潘嗣勤 《军事体育进修学院学报》2004,23(1):79-81

依据人体能量代谢的系统论观点，通过运用阻氧嘴进行双重缺氧训练的研究。阐述了缺氧训练与发展有氧耐力、无氧耐力及其它身体素质之间的关系、论证了双重缺氧训练法的科学性、高效性和经济性。丰富和发展了长跑训练理论，  相似文献   

室内健身场所空气质量及路径健身器械生物性污染的调查与研究     

王跃 《中国体育科技》2004,40(5):35-37

为了解室内健身场所及路径健身器械环境卫生状况,采用公共场所卫生标准检验方法,对郑州市3家大型健身房内空气质量及社区路径健身器械生物性污染现状进行了检测。结果显示,3所健身房内的CO2浓度和细菌总数随着开馆时间延长而增高,与开馆前相比超标5.6%且差异有统计学意义;室内、室外健身器械均受到不同程度的生物性污染,其中社区路径健身器械细菌的检出率分别高于室内健身器械,且差异显著。健身房内空气质量、器械及社区路径健身器械均受到不同程度的污染,健身场所的环境卫生对健身人群的健康直接或间接构成了危害。建议加强公共健身场所的卫生管理工作,制定切实可行的清洁、消毒制度,做好经常性的卫生监督工作,给广大城市居民提供一个清洁卫生的健身环境。  相似文献   

篮球运动中连续起跳技术初探     

毕研嵩  仪名蕾 《山东体育科技》2004,26(1):13-14

篮球运动中制空权的掌握并不仅仅在于对空间高度的控制，还在于对高度控制的持续时间上，因而连续起跳就显得颇为重要；对篮球运动中连接起跳技术的结构、运用及影响因素进行了探讨，并设计了相应的训练方法。  相似文献   

Risk,affect, and policy support: public perception of air pollution in China     

Jialing Huang 《亚洲交流杂志》2018,28(3):281-297

Air pollution is a critical environmental problem that has spurred great public concern in China. This study examines how issue salience, environmental value, risk perception, and affective response influence information seeking, objective knowledge, and policy support related to this issue. The recent release of a controversial environmental documentary on Chinese social media, Under the Dome, also prompted us to explore the impact of exposure to this documentary on Chinese social media users’ information seeking and policy support related to air pollution. Results showed that risk perception and negative affect influenced information seeking and policy support both directly and indirectly. Also, exposure to the documentary moderated the effects of key variables on information seeking and policy support. However, contrary to our expectations, no significant relationship was found between information seeking and objective knowledge. Theoretical and practical implications of these findings were discussed.  相似文献   

Estimating fat-free mass in elite-level male rowers: a four-compartment model validation of laboratory and field methods     

Kristina L. Kendall  David H. Fukuda  Parker N. Hyde  Abbie E. Smith-Ryan  Jordon R. Moon  Jeffrey R. Stout 《Journal of sports sciences》2017,35(7):624-633

The purpose of this study was to investigate the accuracy of fat-free mass (FFM) estimates from two-compartment (2C) models including air displacement plethysmography (ADP), ultrasound (US), near-infrared interactance (NIR), and the Jackson and Pollock skinfold equation (SKF) against a criterion four-compartment (4C) model in elite male rowers. METHODS: Twenty-three elite-level male rowers (mean± SD; age 24.6 ± 2.2 years; stature: 191.4 ± 7.2 cm; mass: 87.2 ± 11.2 kg) participated in this investigation. All body composition assessments were performed on the same day in random order, except for hydrostatic weighing (HW), which was measured last. FFM was evaluated using a 4C model, which included total body water from bioimpedance spectroscopy, body volume from HW, and total body bone mineral via dual-energy X-ray absorptiometry. The major findings of the study were that the 2C models evaluated overestimated FFM and should be considered with caution for the assessment of FFM in elite male rowers. Future studies should use multiple-compartment models, with measurement of TBW and bone mineral content, for the estimation of FFM.  相似文献   

基于STAR-CCM+的汽车挡风玻璃除霜性能提升的仿真分析与研究     

胡忠文 《苏州市职业大学学报》2021,(1)

采用计算流体动力学的方法,利用STAR-CCM+软件对某一车型挡风玻璃除霜性能进行数值模拟分析。通过对出风口格栅进行调整,改变了暖风气流与挡风玻璃之间碰撞角的大小与碰撞点的位置,优化了挡风玻璃表面暖风气流的分布,提升了除霜性能,为汽车除霜风道的设计和改善车辆除霜性能提供了参考。  相似文献   

Kinematic analysis of the drag flick in field hockey     

Rony Ibrahim  Gert S. Faber  Jaap H. van Dieën 《Sports biomechanics / International Society of Biomechanics in Sports》2017,16(1):45-57

Attaining high speed of the stick head and consequently of the ball is essential for successful performance of the drag flick in field hockey, but the coordination pattern used to maximise stick head speed is unknown. The kinematics of the drag flick was studied in ten elite hockey players who performed twenty shots each towards a target located 1.5 m high. A 150 Hz active marker motion analysis system was used, alongside two force plates to detect foot touchdown. Angular velocity and contribution to stick endpoint speed of upper body joints were analysed. Repeated measures ANOVA was used to compare timing of onset and peak angular velocities between joints. Participants used a kinematic pattern that was close to a proximal-to-distal sequence. Trunk axial rotation and lateral rotation towards the target, right wrist flexion and left wrist extension were the main contributors to stick endpoint speed. Coaches should emphasise trunk rotations and wrist flexion and extension movements for maximising stick head speed. Given the high level of the participants in this study, the coordination of joints motions, as reported here, can serve as a guideline for drag flick training.  相似文献   

矿井多风机风压优化计算机调节系统设计     

王国臣  刘宪文 《鸡西大学学报》2001,(3)

经过对多风机通风网络分析,利用现有的VNETPC模拟程序,建立了多风机风压优化计算机调节系统.该系统允许计算机自动调整多风机风压,直到各用风地点获得最佳可接受的风量分配为止.  相似文献