如何加大器械出手速度的思考——以掷标枪为例

掷标枪是田径运动中技术比较复杂的项目之一,出手速度是影响其成绩的重要因素之一,以右手持枪为例来分析如何提高标枪的出手速度。     

国内外优秀男子跳远运动员部分技术指标差异性分析

对国内外优秀跳远运动员和世界顶级跳远运动员的助跑速度利用率、短程和全程助跑跳远成绩差、K值三项指标进行对比分析,发现我国优秀男子跳远运动员助跑速度利用率明显高于世界顶级选手,但技术评定等级低于世界顶级选手,主要原因是起跳环节存在差距。不同运动员最佳的助跑速度利用率存在差别,高助跑速度利用率需要有与之相对应的起跳能力和跑跳结合能力。     

Physical Activity Practices in Elementary Schools and Associations With Physical Education Staffing and Training

Purpose: Authorities recommend that schools provide a variety of opportunities for students to obtain physical activity (PA) before, during, and after school. This study assessed the prevalence of several school PA practices—including measures of quantity and quality of physical education (PE)—in elementary schools and examined the associations of PA practices with school resources (PE staffing, training, and facilities). Method: Surveys were obtained from respondents in nationally representative samples of elementary schools from 2009–2010 to 2011–2012 (1,831 schools). Results: Few schools (20.8%) provided students with PE class every day, but most (76.3%) had an appropriate PE student-to-teacher ratio ( ≤ 25:1). Many schools (74.0%) offered 20 min of recess daily, but fewer than half offered organized opportunities for PA before or after school (e.g., sports). After controlling for demographics and school size, having a full-time PE teacher and requiring PE teachers to obtain PE-related continuing education (CE) were associated with PE practices such as offering ≥ 150 min of PE per week (for 3rd-grade students) and testing PE knowledge, skills, and fitness. Required CE was also associated with a higher likelihood of offering PA during the school day (i.e., activity breaks and PA outside of PE class) and before or after the school day (i.e., afterschool PA programs). Conclusion: Few schools offer a broad array of PA programming. However, PE staffing and CE are positively associated with many PA practices including those outside of PE, possibly indicating that PE staff serve a crucial role in promoting a whole-school PA-supportive environment.     

Effects of official youth taekwondo competitions on jump and strength performance

Abstract

The aim of this study was to investigate differences in athletes’ (7 females, 10 males) motor performances (countermovement jump and handgrip) before and after official youth (13–14 years) taekwondo matches. Exercise load was evaluated by means of the heart rate responses during the match. Independent of round and gender, during the competitions mean heart rate was 187 beats·min^?1 (s=11). During the match, the frequency of heart rate responses above 85% of an individual's maximum heart rate was 77% (s=27). Jump performances showed differences for gender (P=0.044; ES = 0.47) and its interaction with session (P=0.045; ES = 0.49). Female athletes’ post-match countermovement performances were no different from their pre-match performances (pre and post: 22 cm, s=2), whereas male athletes post-match performances (28 cm, s=6) were better than their pre-match performances (25 cm, s=6). Handgrip performances related to the body mass of the athletes showed main effects for session (P=0.017; ES = 0.20) and for gender (P=0.026; ES = 0.47), with no significant interaction. Male athletes showed higher handgrip values (5.8 N·kg^?1, s=0.6) than their female counterparts (5.1 N·kg^?1, s=0.7). For absolute grip strength performances, values were higher pre-match (290.3 N, s=61.4) than post-match (272.4 N, s = 58.3). The heart rate responses indicate that official youth taekwondo competition imposes a high load on athletes. In particular, post-match decreases in isometric grip strength suggest that coaches should better prepare their very young athletes to prevent reductions in muscle force during fighting. Considering that lower limb power remained unaffected or increased depending on gender, further research in this area is strongly recommended.     

男子跳远运动员膝关节肌等速向心收缩的肌力研究

利用cybex-770等速测试与康复系统,对17名一级男子跳远运动员起跳腿的膝关节进行了等速向心收缩测试。所测试的指标包括相对峰力矩、相对总功、相对平均功率、峰力矩屈伸比等,对这些指标进行综合分析,并且结合跳远运动项目下肢肌最大力量和爆发力的项目特点,为优秀运动员有针对性的力量训练提供参考依据。     

2003～2005年世锦赛暨奥运会远跳项目冠军运动员的比赛安排

l前言田径远跳项目包括男女跳远和三级跳远，在这几个项日上我国运动员在世界大赛上都曾取得过辉煌成绩。但近10多年来，除女子三级跳远外，其余三个项目成绩、大赛名次与以往情况大相径庭。本文试图通过对2《X)3年世锦赛、2(X科年奥运会、2(x)5年世锦赛男女跳远、三级跳远第一     

内蒙古地区20一69岁人群BMI特征分析研究

目的：分析内蒙古20-69岁人群BMI特点,采用百分数法评价BMI,寻找超重与肥胖的触发年龄。方法：对5880人数据进行BMI数据分析和曲线拟合分析。结果：①内蒙古20—69岁人群总体、男性、女性BMI分别为24．2±3．48、24．6±3．49、23．8±3．41。总体BMI高于全国平均水平,男性高于女性,超重和肥胖...     

女子排球比赛中大力跳发球与飘球运用对比分析研究

通过对2004年和2008年两届奥运会上女排比赛中大力跳发球与飘球运用的对比分析,为女子排球比赛发球技术的运用提出参考性建议。     

浙江省城市学龄前儿童下肢力量发展特点

对浙江省25所幼儿园3～6岁的5 267名学前儿童进行立定跳远和10m连续跳测试,观察浙江省学龄前儿童的下肢力量发展情况,旨在为评价学前儿童下肢的活动能力及其发展趋势以及探寻运动素质发展敏感期提供参考依据。结果发现3～6岁幼儿的立定跳及连续跳成绩随年龄的增长而显著增加。性别因素对两个指标的测试成绩有明显的影响,但对两次测试的变化率没有影响。分析得出浙江省城市3～6岁男童立定跳能力显著强于同年龄段女童,在3岁时增长速率最大;连续跳成绩男女组在相同年龄段几乎没有差异,结合立定跳成绩分析显示,女童的下肢协调性优于同年龄段男童。     

不同等级跳高运动员膝关节肌群离心收缩时肌力特征研究

分析比较不同级别男子跳高运动员膝关节屈伸肌群离心收缩时峰力矩特点及差异。在首都体育学院生物力学实验室,采用德国ISOMED2000等速测试仪,对8名一级男子跳高运动员和8名二级男子跳高运动员膝关节肌群进行等速离心收缩测试,测试角速度60°/s、120°/s、240°/s,指标包括峰值力矩、相对峰力矩(峰值力矩/体重)、峰值力矩屈伸比。研究结果:(1)一级跳高运动员起跳腿膝关节屈、伸肌峰力矩较二级跳高运动员有显著性差异(P<0.05);(2)平均功率随给定运动角速度的增大而增大(P<0.01);(3)离心收缩峰力矩随给定运动速度的增加无显著变化;(4)离心收缩膝关节屈伸肌群峰力矩比值为0.60～0.63之间。结论:跳高运动员膝关节肌群等速测试结果的差异是造成一、二级跳高运动员成绩差异的原因之一。