优秀自由泳运动员分段时间的特征研究

对近4届世界游泳锦标赛上高水平(决赛和半决赛)自由泳运动员的运动成绩进行分析,其中男、女各224人共历时7年.通过各分段时间与最终成绩的相关分析,以及历届不同水平、性别的优秀运动员在各个项目上的分段时间进行研究.结果发现,在任何项目上,不论水平高低,自由泳运动员都呈现较为类似的时间分配模式,其中在短距离项目上,水平越高的运动员前后半程的分段时间差越小并趋于均衡;在中距离项目上,男子运动员后半程保持速度的能力优于女子,历届世锦赛的获胜者在每个分段上处于领先位置,尤其在途中的游速上;同时长距离项目上水平较高的运动员在途中的分段时间有明显的下降趋势(加速)且变化较小,而水平稍差的运动员有明显的上升趋势(减速).建议教练员和运动员在保持总分段时间分配特征的前提下,通过技术优化和力量训练来提高分段成绩,进一步提高比赛成绩.     

高水平游泳运动员临界速度变化对中长距离自由泳成绩变化影响研究

目的:检验采用比赛数据计算高水平游泳运动员临界速度的可行性和有效性,探索高水平游泳运动员临界速度同比变化对中长距离自由泳成绩同比变化的影响,建立临界速度同比变化对高水平游泳运动员长距离自由泳成绩同比变化概率的预测回归模型。方法:收集2011-2018年中长距离自由泳项目(200～1 500 m)世界游泳排名Top100的信息,采用距离-时间模型计算临界速度,用线性回归评估临界速度与中长距离游泳项目成绩的关系,使用逻辑回归(logistics)评价临界速度同比变化对成绩同比变化的影响。结果:临界速度可以分别解释200 m、400 m、800 m和1 500 m自由泳成绩变化的76.8%、87.2%、90.7%和99.5%。当临界速度同比提高时,长距离项目(800 m和1 500 m)成绩同比提高是成绩同比下降的30倍。当临界速度同比提高/下降1%～6%时,长距离项目(800 m和1 500 m)成绩同比提高/下降的发生概率约为80%～100%。结论:采用比赛参数(比赛成绩和比赛距离)计算临界速度是可行和有效的;临界速度同比变化百分比(提高/下降)能预测成绩同比变化,是解释长距离自由泳成绩...     

中外优秀1500米自由泳运动员游程分析

本文通过对2008年美国、中国、澳大利亚三国游泳冠军赛1500米自由泳决赛运动员成绩进行分析,在揭示优秀1500米自由泳运动员体力分配特点的同时,找出中外运动员在该项目的差异并分析其原因所在,以此为我国1500米自由泳训练提供一定参考。     

Potentiation of sprint cycling performance: the effects of a high-inertia ergometer warm-up

ABSTRACT

Participant and protocol factors affect post-activation potentiation response. Performance enhancement is more consistent in highly-trained participants following multiple sets of a biomechanically similar conditioning activity. Providing optimal conditions, 6 international-level sprint cyclists executed multiple sets of short maximal conditioning contractions on a high-inertia ergometer before metered sprint performance. Three trial conditions were completed on separate days after a standardised warm-up: dynamic (DYN: 4 × 4 crank-cycles), isometric (ISO: 4 × 5-sec maximal voluntary contraction (MVC)), and control (CON: rest). Performance was measured from standing start to maximum velocity on an inertial-load ergometer at baseline (Pre), 4 (Post4), 8 (Post8) and 16 (Post16) min post-conditioning. Performance and biomechanical measures were assessed across 4 sprint segments, with magnitude-based inferences used to assess the likelihood that any affect was beneficial. Performance time only improved in DYN Post4, a 3.9% reduction during the first crank cycle (92% likely). On the ascending limb of the power-cadence relationship, peak torque and average power increased by 6.2% (94% likely) and 4.0% (87% likely), respectively. In ISOPost16, optimal cadence increased (82% likely) and average power improved over the descending limb (76% likely). DYN and ISO potentiated extremities of the torque-cadence relationship at distinct recovery times post-conditioning. This study suggests merit in including a high-inertia warm-up for sprint cycling.     

The categorisation of swimming start performance with reference to force generation on the main block and footrest components of the Omega OSB11 start blocks

Abstract

Work presented in this paper provides a methodology for categorising swimming start performance based on peak force production on the main block and footrest components of the Omega OSB11 starting block. A total of 46 elite British swimmers were tested, producing over 1000 start trials. Overwater cameras were synchronised to a specifically designed start block that allowed the measurement of force production via two sets of four, tri-axis, force transducers; one set in the main block and one in the footrest. Data were then analysed, segregating trials for gender. Each start was categorised, with respect to the peak force production in horizontal and vertical components, into one of nine categories. Three performance indicators, i.e. block time, take-off velocity and distance of entry, were used to assess whether differences in performance could be correlated with these categories. Results from these data suggest that swimmers generating higher than average peak forces were more likely to produce a better overall start performance than those who produced forces lower than the average, for this population of athletes.     

Muscle morphology of the vastus lateralis is strongly related to ergometer performance,sprint capacity and endurance capacity in Olympic rowers

Rowers need to combine high sprint and endurance capacities. Muscle morphology largely explains muscle power generating capacity, however, little is known on how muscle morphology relates to rowing performance measures. The aim was to determine how muscle morphology of the vastus lateralis relates to rowing ergometer performance, sprint and endurance capacity of Olympic rowers. Eighteen rowers (12♂, 6♀, who competed at 2016 Olympics) performed an incremental rowing test to obtain maximal oxygen consumption, reflecting endurance capacity. Sprint capacity was assessed by Wingate cycling peak power. M. vastus lateralis morphology (volume, physiological cross-sectional area, fascicle length and pennation angle) was derived from 3-dimensional ultrasound imaging. Thirteen rowers (7♂, 6♀) completed a 2000-m rowing ergometer time trial. Muscle volume largely explained variance in 2000-m rowing performance (R² = 0.85), maximal oxygen consumption (R² = 0.65), and Wingate peak power (R² = 0.82). When normalized for differences in body size, maximal oxygen consumption and Wingate peak power were negatively related in males (r = ?0.94). Fascicle length, not physiological cross-sectional area, attributed to normalized peak power. In conclusion, vastus lateralis volume largely explains variance in rowing ergometer performance, sprint and endurance capacity. For a high normalized sprint capacity, athletes may benefit from long fascicles rather than a large physiological cross-sectional area.