排序方式： 共有109条查询结果，搜索用时 15 毫秒
101.
Gary McEwan Rosemary Arthur Shaun M Phillips Neil V Gibson 《European Journal of Sport Science》2018,18(8):1058-1067
This study (1) compared the physiological responses and performance during a high-intensity interval training (HIIT) session incorporating externally regulated (ER) and self-selected (SS) recovery periods and (2) examined the psychophysiological cues underpinning SS recovery durations. Following an incremental maximal exercise test to determine maximal aerobic speed (MAS), 14 recreationally active males completed 2 HIIT sessions on a non-motorised treadmill. Participants performed 12?×?30?s running intervals at a target intensity of 105% MAS interspersed with 30?s (ER) or SS recovery periods. During SS, participants were instructed to provide themselves with sufficient recovery to complete all 12 efforts at the required intensity. A semi-structured interview was undertaken following the completion of SS. Mean recovery duration was longer during SS (51?±?15?s) compared to ER (30?±?0?s; p?d?=?1.46?±?0.46). Between-interval heart rate recovery was higher (SS: 19?±?9?b?min?1; ER: 8?±?5?b?min?1; p?d?=?1.43?±?0.43) and absolute time ≥90% maximal heart rate (HRmax) was lower (SS: 335?±?193?s; ER: 433?±?147?s; p?=?.075; d?=?0.52?±?0.39) during SS compared to ER. Relative time ≥105% MAS was greater during SS (90?±?6%) compared to ER (74?±?20%; p?d?=?0.87?±?0.40). Different sources of afferent information underpinned decision-making during SS. The extended durations of recovery during SS resulted in a reduced time ≥90% HRmax but enhanced time ≥105% MAS, compared with ER exercise. Differences in the afferent cue utilisation of participants likely explain the large levels of inter-individual variability observed. 相似文献
102.
网球运动中疲劳与恢复的探讨 总被引：4，自引：0，他引：4
本文论述了网球运动中疲劳的特点和产生疲劳的一些综合表现形式，阐明了网球运动中疲劳产生的机制，提出了预防和消除疲劳的一些途径和方法。 相似文献
103.
肱二头肌等长收缩时表面肌电积分的动态变化 总被引：1，自引：0，他引：1
通过对持续等长性收缩的肱二头肌的表面肌电积分的观察，研究了肱二头肌在运动开始到肌肉疲劳的整个运动过程中，肌肉生物电动态变化特征。 相似文献
104.
吴新林 《乐山师范学院学报》2013,28(5):46-48
本试验研究旨在通过CFF测量和主观评价来探讨视频显示装置(VDT)的大小对视疲劳的影响。客观手段为测量不同试验条件下受试者在实验前后的CFF差值,主观手段为Borg疲劳量表、不适部位评价和主观偏好评价,并辅以行为观察。试验结果表明:VDT尺寸大小对视疲劳具有一定的影响;男女对不同视频大小条件的适应情况存在性别差异;尺寸大小对VDT作业的坐姿行为具有一定的影响。 相似文献
105.
A significant temperature raise within hydrogen vehicle cylinder during the fast filling process will be observed, while the strength and fatigue life of the cylinder will dramatically decrease at high temperature. In order to evaluate the strength and fatigue of composite hydrogen storage vessel, a 70-MPa fatigue test system using hydrogen medium was set up. Experimental study on the fatigue of composite hydrogen storage vessels under real hydrogen environment was performed. The experimental results show that the ultimate strength and fatigue life both decreased obviously compared with the values under hydraulic fatigue test. Furthermore, fatigue property, failure behavior, and safe hydrogen charging/discharging working mode of onboard hydrogen storage vessels were obtained through the fatigue tests. 相似文献
106.
Devi CHANDRA ;Judha PURBOLAKSONO ;Yusoff NUKMAN ;Haw-ling LIEW ;Singh RAMESH ;Mohsen-abdel HASSAN 《浙江大学学报(A卷英文版)》2014,15(11):873-882
研究目的：在相同的反复张力下,研究V形切口圆条表面裂纹的疲劳扩展规律。研究方法：1.构建V形切口圆条模型（图1）,基于线性二次元将模型表面离散成一个个网格点（图2）;2.以AZ-6A-T5镁合金为例,利用J积分计算应力强度因数,利用NASGRO裂纹增长率模拟裂纹的疲劳扩展;3.通过研究不同的裂纹纵横比和对应的应力强度因数之间的相关性来研究裂纹的扩展。重要结论：1.在裂纹扩展时裂纹纵横比的初始值对断裂形状的发展有重要影响;2.裂纹纵横比对疲劳负荷寿命的作用比缺口半径更加明显;3.当裂纹前缘演变成一条直线形时可观察到不稳定的裂纹扩展;4.裂纹深度一定时,断裂纵横比越小,疲劳负荷寿命越短;5.当裂纹纵横比为0.6-0.7时,出现了不稳定的裂纹扩展。 相似文献
107.
《运动与健康科学(英文)》2014,3(2):122-130
PurposeTo observe the relative change in foot-strike pattern, pressure characteristics, surface electromyography (sEMG) recordings, and stride characteristics in forefoot strike runners wearing both minimalist and traditional shoes during a 50-km run.MethodsFour experienced minimalist runners were enrolled in this study. Each runner ran a 50-km simulated run in both minimalist shoes and traditional shoes. Pressure data, sEMG recordings, and limited 3D motion capture data were collected during the initial 0.8 km and final 0.8 km for each trial.ResultsThree runners in the traditional shoe type condition and one runner in the minimalist shoe type condition demonstrated a more posterior initial contact area (midfoot strike (MFS) pattern) after the 50-km run, which was supported by increased activity of the tibialis anterior in the pre-contact phase (as per root mean square (RMS) values). In addition, in both pre- and post-run conditions, there were increased peak pressures in the minimalist shoe type, specifically in the medial forefoot. Muscle fatigue as defined by a decreased median frequency observed in isometric, constant force contractions did not correspond with our hypothesis in relation to the observed foot strike change pattern. Finally, step rate increased and step length decreased after the 50-km run in both shoe type conditions.ConclusionMore runners adopted a more posterior initial contact area after the 50-km run in the traditional shoe type than in the minimalist shoe type. The runners who adopted a more posterior initial contact area were more closely associated with an increased median frequency of the medial gastrocnemius, which suggests there may be a change in motor unit recruitment pattern during long-distance, sustained velocity running. The increased peak pressures observed in the medial forefoot in the minimalist shoe type may predispose to metatarsal stress fractures in the setting of improper training. 相似文献
108.
目前,已有大量实验表明,左旋肉碱、泛酸、支链氨基酸、辅酶Q10等营养素对于运动疲劳有延缓作用,作为强有力的运动营养补剂已经被广泛运用到体育锻炼和抗运动性疲劳当中。该文采用文献资料法对运动性疲劳的变化特征进行综述,并且针对不同机制合理使用补给做出阐释和说明,旨在为运动训练水平的提升和大众健身能力的提高提供科学、有效的参考。 相似文献
109.
陶瓷轴承研究状况与发展前景 总被引：4，自引：0，他引：4
系统阐述了陶瓷轴承的发展历史和研究状况 ,分析了氮化硅陶瓷轴承的性能及其存在问题 ,指出陶瓷轴承的发展趋势和研究方向 ,为陶瓷轴承的深入研究和开发提供参考依据 . 相似文献