对高校女子手球与女子足球运动员无氧阈及其主观感觉的探讨

本研究通过功率自行车进行渐增负荷运动 ,测定了 2 1名高校优秀女子手球及足球运动员最大吸氧量 (VO2 max)、无氧阈 (AT)及无氧阈时主观感觉 (RPE- AT)。结果表明女子大学生手球与足球运动员相比 ,虽然运动项目不同 ,但是最大吸氧量、无氧阈及其时的主观感觉却无明显的差异。研究认为这两种不同的运动项目不影响大学生运动员的最大吸氧量、无氧阈及无氧阈时主观感觉 ,同时这些指标可作为评定高校优秀女子运动员有氧耐力的指标     

Characteristics of high-level youth soccer players: variation by playing position

The present study aimed to investigate positional differences in 744 high-level soccer players, aged 8 to 18 years. Players were assigned to six age groups (U9–U19) and divided into four playing positions (goalkeeper (GK), defender (DEF), midfielder (MF) and attacker (ATT)). MANOVA and effect sizes were used to examine anthropometrical and functional characteristics between all positions in all age groups. The main findings of the study were that GKs and DEFs were the tallest and heaviest compared with MFs and ATTs in all age groups. Further, between U9–U15, no significant differences in functional characteristics were found, except for dribbling skill, which MFs performed the best. In the U17–U19 age groups, ATTs seemed to be the most explosive (with GKs), the fastest and the more agile field players. These results suggest that inherent physical capacities (i.e., speed, power, agility) might select players in or reject players from an attacking position, which is still possible from U15–U17. Apparently, players with excellent dribbling skills at younger age are more likely to be selected to play as a MF, although, one might conclude that the typical physical characteristics for different positions at senior level are not yet fully developed among young soccer players between 8 and 14 years.     

The effect of heavy resistance exercise on repeated sprint performance in youth athletes

This investigation assessed whether prior heavy resistance exercise would improve the repeated sprint performance of 16 trained youth soccer players (Age 17.05 ± 0.65 years; height 182.6 ± 8.9 cm; body mass 77.8 ± 8.2 kg). In session 1, individual 1 repetition max was measured utilising a squat movement. In sessions 2 and 3, participants performed a running-based repeated anaerobic sprint test with and without prior heavy resistance exercise of 91% of their 1 repetition max. Times were recorded for each of the 6 sprints performed in the repeated sprint test and summed to provide total time. T-tests compared the two exercise conditions via differences in corresponding sprint times and total time. Analysis revealed significantly reduced total time with use of heavy resistance exercise (33.48 (±1.27) vs. 33.59 (±1.27); P = 0.01). Sprints 1 (P = 0.05) and 2 (P = 0.02) were also faster in the heavy resistance exercise condition (5.09 (±0.16) vs. 5.11 (±0.16) and 5.36 (±0.24) vs. 5.45 (±0.26) seconds respectively) although no other differences were shown. Findings demonstrate improved sprint times of trained adolescent soccer players after heavy resistance exercise although benefits appear not as sustained as in adult participants.     

Effects of sodium phosphate and caffeine loading on repeated-sprint ability

The effects of sodium phosphate and caffeine supplementation were assessed on repeated-sprint ability. Using a randomised, double-blind, Latin-square design, 12 female, team-sport players participated in four trials: (1) sodium phosphate and caffeine, (2) sodium phosphate and placebo (for caffeine), (3) caffeine and placebo (for sodium phosphate) and (4) placebo (for sodium phosphate and caffeine), with ~21 days separating each trial. After each trial, participants performed a simulated team-game circuit (4 × 15 min quarters) with 6 × 20-m repeated-sprints performed once before (Set 1), at half-time (Set 2), and after end (Set 3). Total sprint times were faster after sodium phosphate and caffeine supplementation compared with placebo (Set 1: P = 0.003; Set 2: d = ?0.51; Set 3: P < 0.001; overall: P = 0.020), caffeine (Set 3: P = 0.004; overall: P = 0.033) and sodium phosphate (Set 3: d = ?0.67). Furthermore, total sprint times were faster after sodium phosphate supplementation compared with placebo (Set 1: d = ?0.52; Set 3: d = ?0.58). Best sprint results were faster after sodium phosphate and caffeine supplementation compared with placebo (Set 3: P = 0.007, d = ?0.90) and caffeine (Set 3: P = 0.024, d = ?0.73). Best sprint times were also faster after sodium phosphate supplementation compared with placebo (d = ?0.54 to ?0.61 for all sets). Sodium phosphate and combined sodium phosphate and caffeine loading improved repeated-sprint ability.     

MATLAB辅助核反应堆工程专业的教学探索

MATLAB仿真软件是一套功能强大的数值计算和可视化软件,广泛应用于数值计算、系统的建模、分析和设计中。简要介绍了核反应堆工程专业的课程特点,通过实例重点阐述了MATLAB在课程中的具体应用。实践证明,利用MATLAB辅助教学,有助于学生理解和掌握比较抽象的问题,有效提高教学效果与教学质量。     

2010年冬奥会前国家短道速滑队女子运动员无氧运动能力检测及特征的辩证分析

通过Short-term anaerobic,Intermediate-term anaerobic test,120 sec maximal test 3种无氧运动能力的测试方法,对国家短道速滑队备战2010年冬奥会的7名主力运动员的无氧运动能力进行测试分析。探讨优秀短道速滑运动员在备战奥运会前无氧运动能力的状态、特点以及规律,揭示了短道速滑运动员原发性、保持性和持续性无氧运动能力之间的基本关联;研究结果表明,我国女子短道速滑队运动员原发性和保持性无氧运动能力优于韩国女队,持续性无氧运动能力与韩国女队有很大差距,建议在未来的训练中把握三种无氧运动能力之间的动态关系,以持续性无氧运动能力为主,运用多种训练方法以及不同的滑跑速度和强度点分级进行训练将对专项无氧能力的提高具有重要的指导作用。     

国内篮球运动员无氧耐力测试方法的不足——忽视篮球运动专项特征

篮球运动员的体能测试是体能训练科学化的重要步骤,选择符合篮球专项特征的测试方法是进行有效体能测试的前提。综述了国内外关于篮球项目特征及无氧耐力场地测试方法的相关研究。结果发现,我国所选用的关于篮球运动员的无氧耐力测试的方法及计量指标尚存在不足,忽略了结合专项特征带有间歇性质的反复冲刺能力的测试(repeated sprint test)和反复跳跃测试。在此基础上,介绍了同类项群运动员反复冲刺能力和跳跃的测试方法,并总结其设计原理。     

8周跑台运动对大鼠血清LDH、LA、CK影响的研究

以Wistar雄性大鼠为研究对象,探讨不同运动方式对同龄大鼠代谢终产物乳酸（lactic acid）和血清乳酸脱氢酶（lactate dehydrogenase,LDH）、肌酸激酶（creatine kinase,CK）的影响。结果：经过8周的跑台运动训练后,与对照组相比,无氧、有氧训练组大鼠血乳酸水平出现非常显著性差异（P〈0.01）,无氧组的LDH活性值显著升高（P〈0.01）,而有氧组没有显著性差异;无氧训练组组内第8周与静息值相比出现非常显著性差异（P〈0.01）,而有氧训练组组内LDH活性始终无明显变化。经过8周的训练,无氧组大鼠血清中肌酸激酶的活性有了很大提高（P〈0.01）,组间组内均具有显著性差异;有氧组肌酸激酶的活性也有了一定的提高,但较无氧组变化较小;对照组几乎无明显变化。结论：经过8周的跑台训练后,两种训练方式均有效提高了大鼠的血乳酸水平。不同方式的跑台运动训练后,大鼠血清乳酸脱氢酶的活性变化出现在无氧组中,显示无氧组的运动强度更能刺激大鼠血清LDH水平。两个训练组大鼠血清CK值,横向组间比较和纵向组内对比均出现显著性变化,表明大鼠血清CK值对运动负荷量比较敏感;无氧组横向组间比较和纵向组内对比,均比有氧组有更显著的变化,表明大鼠血清CK值能够反映运动负荷强度的变化。     

辽宁女子皮艇运动员体成分研究

采用文献资料法、统计分析法和实验法,分析了辽宁女子皮艇队员一段时间体成分的变化特点,并结合有氧无氧能力指标进行分析,结果表明:与高水平运动员相比,女皮现阶段体脂水平较高,应注意改善体成分。     

不同训练方式对足球运动员体内血清酶和尿素氮的影响

对12名二级男子足球运动员进行三种不同类型的运动训练,分别测定运动后及恢复期间血清酶和尿素氮.探讨各指标在不同训练方式、不同恢复期间的变化情况,从而为科学训练提供客观依据.