The effect of a resistance training programme on the grab,track and swing starts in swimming

The aim of this study was to establish the effectiveness of a resistance training programme, designed to improve vertical jumping ability, on the grab, swing and rear-weighted track starts in swimming. Twenty-three female non-competitive swimmers participated (age 19.9 +/- 2.4 years; mean +/- s). The diving techniques were practised weekly for 8 weeks. The participants were randomly assigned to a control group (n = 11) or a resistance-training group (n = 12), which trained three times a week for 9 weeks. The tests before and after the training programme involved performing each dive technique and six dry-land tests: two countermovement jumps (with and without arms), two isokinetic squats (bar speeds of 0.44 and 0.70 rad x s(-1)) and two overhead throws (with andwithout back extension). A repeated-measures multivariate analysis of variance was used to show that resistance training improved performance in the dry-land tests (P < 0.0001). No significant improvements due to training were found for any temporal, kinematic or kinetic variables within the grab or swing starts. Significant improvements (P < 0.05) were found for the track start for take-off velocity, take-off angle and horizontal impulse. The results suggest that the improved skill of vertical jumping was not transferred directly to the start, particularly in the grab technique. Non-significant trends towards improvement were observed within all starts for vertical force components, suggesting the need to practise the dives to retrain the changed neuromuscular properties.     

游泳运动对肥胖及肥胖抵抗型NAFLD大鼠干预效果的对比研究

探讨肥胖及肥胖抵抗大鼠NAFLD发病机制及运动干预对不同倾向模型的效果是否存在不同之处,为更好防治NAFLD提供实验数据.通过高脂饮食诱导建模,从中遴选出肥胖和肥胖抵抗型两种大鼠,通过肝组织病理切片确定建模是否成功.而后对大鼠施加5周的游泳运动,运动结束后,通过测定体脂、脂体比,血脂、肝指数、瘦素水平、空腹血糖及胰岛素水平等指标,观察运动对不同类型NAFLD的干预效果.结果发现,肥胖抵抗组体质量与正常组相比差异无显著性,但肥胖抵抗组与肥胖组同样存在能量代谢紊乱,肥胖组存在胰岛素抵抗和瘦素抵抗,肥胖抵抗组不显示有胰岛素抵抗,存在瘦素抵抗.游泳运动改善肥胖组NAFLD的效果较肥胖抵抗组更为显著.结果表明肥胖组NAFLD与肥胖抵抗组NAFLD发病机制并不相同,游泳运动对其干预效果也不相同.游泳运动使能耗增加,减少脂质沉积,能明显改善肥胖组的瘦素抵抗,恢复脂肪-胰岛素的负反馈调节机制,进而改善IR,促进NAFLD转归.游泳运动对肥胖抵抗组的改善机制可能不同于肥胖组,主要是通过调节瘦素的受体结合率,改善瘦素抵抗,促进NAFLD的转归.     

Nutrition for power sports: middle-distance running, track cycling, rowing, canoeing/kayaking, and swimming

Contemporary training for power sports involves diverse routines that place a wide array of physiological demands on the athlete. This requires a multi-faceted nutritional strategy to support both general training needs--tailored to specific training phases--as well as the acute demands of competition. Elite power sport athletes have high training intensities and volumes for most of the training season, so energy intake must be sufficient to support recovery and adaptation. Low pre-exercise muscle glycogen reduces high-intensity performance, so daily carbohydrate intake must be emphasized throughout training and competition phases. There is strong evidence to suggest that the timing, type, and amount of protein intake influence post-exercise recovery and adaptation. Most power sports feature demanding competition schedules, which require aggressive nutritional recovery strategies to optimize muscle glycogen resynthesis. Various power sports have different optimum body compositions and body weight requirements, but increasing the power-to-weight ratio during the championship season can lead to significant performance benefits for most athletes. Both intra- and extracellular buffering agents may enhance performance, but more research is needed to examine the potential long-term impact of buffering agents on training adaptation. Interactions between training, desired physiological adaptations, competition, and nutrition require an individual approach and should be continuously adjusted and adapted.     

游泳运动员前倾蹲踞式出发时间与技术指标的相关性研究

运用统计学方法找出影响前倾式蹲踞式出发时间的主要水上及水下技术指标。选取山东省优秀游泳女运动员10名,运用2台陆上摄像机、1台水下摄像机与1台测力起跳台同步定机拍摄15 m 完整出发技术动作周期,使用 Kwon3D 和 Biowave 进行运动学和动力学数据解析,使用统计学软件 SPSS 对26个指标进行了相关性分析,发现前倾式蹲踞式出发总时间受水下时间的影响;出发台上时间受后腿膝关节角度和蹬离时间的影响;出发腾空时间受起跳角和腾空高度的影响;水下时间受入水深度、水下打腿次数、入水角、水下水平初速度和滑行髋关节角度的影响;腾空时间影响入水距离和入水水平初速度;腾空阶段髋关节角度影响入水水平初速度;前脚水平蹬离最大力量影响入水水平初速度和水下水平初速度;起跳角和前后脚水平蹬离力量影响离台水平速度,离台水平速度影响腾空高度、入水角、入水距离。     

花样滑冰阿克塞尔跳的生物力学分析

花样滑冰运动员在比赛中,阿克塞尔跳是所有跳跃里最困难的一种,利用生物力学原理对阿克塞尔跳进行分析发现,垂直速度相对身体纵轴角动量以及相对身体纵轴转动惯量的控制,是滑冰跳跃中最重要的3个因素。     

拳击摆拳动作的生物力学分析与评价

从生物力学的角度,对拳击摆拳的动作效果进行分析与评价。分析摆拳的上肢摆动、躯干转动、下肢蹬伸的肌群工作特点。分析认为,摆拳效果与动作速度、动作方向、动作时间、动作幅度有直接关系。     

The effect of a fast bowling harness in cricket: an intervention study

The influence of a bowling harness, as a training aid, was assessed as a means of modifying bowling technique. Thirty-three 13-year-old bowlers received a standardized 15 min of bowling coaching twice a week for 8 weeks. They were randomly assigned to one of two groups. The 13 participants in the intervention group used the bowling harness throughout the coaching, while also receiving verbal and visual feedback. The 20 participants in the non-harness group received the same visual and verbal feedback. Three-dimensional videography (200 Hz) of each player's bowling action enabled the calculation of transverse plane shoulder alignment counter-rotation, separation angle, lateral flexion and hyperextension of the trunk before and after the intervention. The restriction applied by the harness produced a significant reduction ( P = 0.006) in separation angle and forced the bowler to adopt a position at back-foot impact that reduced the 'twist' in the spine. However, it had no effect on restricting other aspects of trunk movement during the critical phases of the bowling action. No significant long-term modifications to technique were found after the coaching intervention when players were assessed without the harness.     

The effect of a fast bowling harness in cricket: an intervention study

The influence of a bowling harness, as a training aid, was assessed as a means of modifying bowling technique. Thirty-three 13-year-old bowlers received a standardized 15 min of bowling coaching twice a week for 8 weeks. They were randomly assigned to one of two groups. The 13 participants in the intervention group used the bowling harness throughout the coaching, while also receiving verbal and visual feedback. The 20 participants in the non-harness group received the same visual and verbal feedback. Three-dimensional videography (200 Hz) of each player's bowling action enabled the calculation of transverse plane shoulder alignment counter-rotation, separation angle, lateral flexion and hyperextension of the trunk before and after the intervention. The restriction applied by the harness produced a significant reduction (P= 0.006) in separation angle and forced the bowler to adopt a position at back-foot impact that reduced the 'twist' in the spine. However, it had no effect on restricting other aspects of trunk movement during the critical phases of the bowling action. No significant long-term modifications to technique were found after the coaching intervention when players were assessed without the harness.     

Evaluation of an anti-doping intervention for adolescents: Findings from a school-based study

The present study investigated the effectiveness of a school-based intervention in promoting an anti-doping culture in adolescents. Participants were 218 high school students attending Health Education programs in Greek secondary education. Students completed a questionnaire including measures of attitudes towards nutritional supplement and doping use, social norms and norm salience, and values and harms of sport. The intervention consisted of 10 teaching units focusing on the health, moral, social and psychological aspects of nutritional supplement and doping use. The results showed that intervention group participants reported significantly weaker attitudes towards doping use, and increased norm salience. Health was ranked as the most important value of sport in both intervention and control groups, and doping use was ranked as the most important threat to the integrity of sport in the intervention group. The findings are discussed with respect to policy making and the role of school-based interventions in promoting an anti-doping culture in young people.     

成都市大众游泳消费市场调查与分析

游泳作为一项很好的大众健身运动,在成都市有着广泛的群众基础.研究成都市群众游泳消费活动现状,对于服务游泳健身、游泳场馆经营具有现实意叉.     

跳远踏跳教学阶段的生物力学分析

从生物力学的角度对跳远踏跳阶段的诸因素进行探讨，其中最主要的是：着板时制动点的稳定性，支撑腿踝膝关节的锁紧程度，摆动动作的效果以及蹬伸过程肌肉发力的顺序等因素，为科学制定教学计划提供了一定的理论依据。     

田径教学中同伴教育对预防运动损伤的干预实效

为探讨在田径教学中实施同伴教育对预防运动损伤的干预实效,选取本校2008级10个田径教学班共计240名学生为干预对象,针对运动损伤方面施以为期4个月同伴教育.结果显示,教育后学生得分高于教育前,差异有非常显著性意义(P<0.01);教育后损伤发生率低于教育前,差异有非常显著性意义(P<0.01);教育后中度和重度损伤发生率均显著低于教育前(P<0.05).实施同伴教育对预防运动损伤有显著效果.     

三种游泳教学法教学效果的检测与分析

选取暨南大学选修大学体育游泳课程的大学生游泳初学者30人为研究对象;随机分为3组,分别采用一般游泳教学法、原地式韵律呼吸游泳教学法和移动式韵律呼吸游泳教学法,每组10人,每周上课1次,共9周,游泳能力测试指标为换气次数和游泳距离。测试结果显示,移动式韵律呼吸游泳教学法,对于初学游泳者换气次数与游泳距离的帮助最具显著性,其次为原地式韵律呼吸游泳教学法,一般游泳教学法最差。因此,移动式韵律呼吸游泳教学法可有效地快速提高普通高校大学生游泳初学者的游泳能力。     

宁波大学游泳教学的现状调查与分析

游泳教学是体育教学的重要组成部分,是提高身体素质的一个有效手段。通过对我校98 级学生的问卷调查与分析,发现:由于种种原因学生掌握游泳技术的合格率极低,难以完成学校提出的任务。对此,从影响掌握游泳技术的因素着手,分析原因,提出措施与对策。     

中日竞技田径国家整体实力的比较研究

以2000年中日两国田径前20名选手为研究对象，从最好成绩、男女水平及集团优势等方面对我国与日本田径选手进行了比较分析，揭示了两国田径整体实力，探寻其劣势及优势，为我国田径项目的合理布局及制订战略步骤提供理论依据。     

田径竞赛新旧规则对比分析

通过对田径新旧规则常用部分的对比分析,目的在于帮助广大体育工作者加深对规则修改部分的理解、掌握;同时提出:教练员、运动员和裁判工作人员应主动适应规则的变化以及基层田径运动会灵活运用规则的建议.     

第29届奥运会游泳比赛评析

对第29届北京奥运会游泳比赛赛沉进行分析,以丰富的数据告剖析当今世界泳坛格局的变化以及我国竞技游泳水平的现状,结果表明：美澳两国实力强劲,共夺得18枚金牌,超过总金牌数32枚中的一半;奖牌榜上的国家数量在增加。竞争愈演愈烈;游泳项目共创28项奥运会纪录,其中21项创世界纪录;中国游泳队以1金3银2铜,6枚奖牌的成绩位列奖牌榜第3名,还有3人1队玻3项世界纪录,全队实际参赛的39人中,有25人提高了最好成绩,实现了近年来中国游泳队在国际大赛上取得的最佳成绩。     

Effect of swimming velocity on arm coordination in the front crawl: a dynamic analysis

We examined the preferred mode of arm coordination in 14 elite male front-crawl swimmers. Each swimmer performed eight successive swim trials in which target velocity increased from the swimmer's usual 3000-m velocity to his maximal velocity. Actual swim velocity, stroke rate, stroke length and the different arm stroke phases were then calculated from video analysis. Arm coordination was quantified by an index of coordination based on the lag time between the propulsive phases of each arm. The index expressed the three coordination modes in the front crawl: opposition, catch-up and superposition. First, in line with the dynamic approach to movement coordination, the index of coordination could be considered as an order parameter that qualitatively captured arm coordination. Second, two coordination modes were observed: a catch-up pattern (index of coordination= -8.43%) consisting of a lag time between the propulsive phases of each arm, and a relative opposition pattern (index of coordination= 0.89%) in which the propulsive phase of one arm ended when the propulsive phase of the other arm began. An abrupt change in the coordination pattern occurred at the critical velocity of 1.8 m. s(-1), which corresponded to the 100-m pace: the swimmers switched from catch-up to relative opposition. This change in coordination resulted in a reorganization of the arm phases: the duration of the entry and catch phase decreased, while the duration of the pull and push phases increased in relation to the whole stroke. Third, these changes were coupled to increased stroke rate and decreased stroke length, indicating that stroke rate, stroke length, the stroke rate/stroke length ratio, as well as velocity, could be considered as control parameters. The control parameters can be manipulated to facilitate the emergence of specific coordination modes, which is highly relevant to training and learning. By adjusting the control and order parameters within the context of a specific race distance, both coach and swimmer will be able to detect the best adapted pattern for a given race pace and follow how arm coordination changes over the course of training.     

Bilateral inter-arm coordination in freestyle swimming: Effect of skill level and swimming speed

The aim of this study was to examine the influence of level of skill and swimming speed on inter-limb coordination of freestyle swimming movements. Five elite (2 males, 3 females; age 18.9?±?1.0 years, height 1.71?±?0.04?m, body mass 62.1?±?7.0?kg) and seven novice (age 22.0?±?2.0 years, height 1.77?±?0.04?m, body mass 74.8?±?9.0?kg) swimmers swam a sprint and a self-paced 25?m freestyle trial. The swimming trials were recorded by four digital cameras operating at 50 Hz. The digitized frames underwent a three-dimensional direct linear transformation to yield the three-dimensional endpoint kinematic trajectories. The spatio-temporal relationship between the upper limbs was quantified by means of the peak amplitude and time lag of the cross-correlation function between the right and left arm's endpoint trajectories. A strong anti-phase coupling between the two arms, as confirmed by peak amplitudes greater than 0.8, was noted for both groups and swimming speeds. Significantly higher (P <?0.05) peak amplitudes were observed for the sprint compared with self-paced swimming. No significant differences in the strength of inter-limb coupling were noted between the elite and novice swimmers (P >?0.05). Time lags were very close to 0?ms and did not differ between groups or swimming speeds. We conclude that in freestyle swimming, the intrinsic anti-phase (180° phase difference) inter-limb relationship is strongly preserved despite the physically powerful environmental influence of the water and this “preferred” pattern is not affected by level of skill. In contrast, increasing movement speed results in stronger inter-limb coupling that is closer to the anti-phase inter-limb relationship.