不同专项运动训练对男大学生运动员骨密度的影响

目的探讨不同专项运动训练对男大学生运动员身体各部位骨密度(BMD)的影响。方法对网球专项、足球专项训练的男性大学生运动员各15名,无正规运动训练同龄大学生15名(对照组)进行BMD测试,测试部位分别为:左右前臂各区域、左右侧股骨各区域骨密度值。结果 2组训练组各部位BMD与对照组比较,均有升高的趋势,且大部分区域具有显著性差异;网球专项组与足球专项组比较,左右前臂有升高的趋势,其中一部分区域BMD有显著性差异,左右侧股骨BMD差异不明显。结论不同专项运动对不同部位的骨密度值影响有差异,运动训练能有效地提高男大学生机体的BMD及身体素质。     

不同运动方式对生长期大鼠骨密度和生物力学指标的影响

目的:建立跳跃运动模型,比较游泳和跳跃两种不同的运动方式对生长期大鼠骨发育的影响,以期为骨健康寻找合理的运动方式.方法:通过自制大鼠跳跃运动模型.以18只4周龄SD大鼠为实验对象,分为对照组、游泳组和跳跃组.8周后,测量所有大鼠的骨密度和骨生物力学指标.结果:游泳组大鼠1～4腰椎BMD比对照组显著性升高,第五腰椎生物力学指标也比对照组显著性升高,股骨BMD生物力学性能与对照组相比没有显著性差异;跳跃组大鼠1～4腰椎和股骨BMD与对照组相比有显著的升高,第五腰椎和股骨的生物力学指标也比对照组显著性升高.结论:游泳运动对生长期大鼠腰椎发育有明显作用,而对股骨作用不明显;跳跃运动对生长期大鼠腰椎和股骨的发育都有明显的促进作用.     

不同运动方式对生长期大鼠骨密度和组织形态计量学指标的影响

目的:比较游泳和跳跃两种不同的运动方式对生长期大鼠骨发育的影响,以期为骨健康寻找合理的运动方式.方法:通过自制大鼠跳跃运动模型,以18只雄性4周龄SD大鼠为实验对象,分为对照组、游泳组和跳跃组.8周后,测量所有大鼠的骨密度、骨组织形态计量学指标.结果:游泳组大鼠1～4腰椎BMD比对照组显著性升高,股骨BMD与对照组相比没有显著性差异,胫骨组织形态计量学指标与对照组相比也没有显著性差异;跳跃组大鼠1～4腰椎和股骨BMD与对照组相比都有显著性升高,胫骨组织形态计量学指标也明显优于对照组.结论:游泳运动对生长期大鼠腰椎发育有明显作用,而对股骨和胫骨作用不明显;跳跃运动对生长期大鼠腰椎、股骨和胫骨的发育都有明显的促进作用.     

男性青少年血清IGF-1浓度与下肢骨骼、肌肉形态、机能发育的关系

探讨男性青少年生长发育过程中血清IGF-1水平与下肢骨骼和肌肉形态、机能发育的关系以及运动训练对青少年生长发育及血IGF-1分泌规律的影响。对68名青春发育期男性青少年的身高、体重、下肢长、小腿长以及小腿三头肌肌腹和肌腱长度等身体形态学指标及反映下肢跳跃能力的指标进行测试、同步检测了血清IGF-1浓度。结果发现,样本男性青少年的血清IGF-1浓度在9-12岁以前升高不明显,12-13岁骤然升高,15岁达到最高峰后,缓慢下降;样本男性青少年在青春发育前期运动训练组与非运动训练组和青春发育后期运动训练组与非运动训练组血清IGF-1浓度无显著性差异。提示运动训练并未影响血清IGF-1的分泌规律。除体脂外,样本所有的生长发育指标均与IGF-1有正相关关系。垂直跳高度,连续跳高度在运动训练组与非运动训练组之间均存在显著性差异,并与血IGF-1水平呈正相关。     

运动对中等职业学校学生骨密度的影响

采用文献法资料法和实验法调查119名中等职业学校学生（以下简称中职生）（16～18岁）的骨密度（bone mineral density，BMD）和参加运动的情况。结果显示男性运动组与不运动组BMD值有显著差异性。女性中职生运动组有使骨密度增加的趋势。运动时间长、运动频率高的组别BMD也高。男性每日运动时间大于1h组与小于1h组的BMD值具有显著性差异。结论：运动对BMD有积极影响，运动频率大于3次／周及每日运动时间超过1h对BMD的影响最为明显。     

国家高水平体育后备人才基地选材测试指标体系对青少年运动员运动项目定位的应用性探索

目的：通过构建运动项目定位模型，探索“国家高水平体育后备人才基地”选材测试指标体系对青少年运动员的运动项目定位的效果，进一步获得有助于人才识别的选材特征指标。方法：以近五年（2015—2019年）上海市两所市级体育运动学校的11~18岁青少年运动员（男性663名、女性662名）为研究对象，每两岁为一组，采用标准式判别分析探索基地选材测试体系对运动员所从事运动项目的正确定位能力，步进式判别分析更进一步筛选出在运动项目定位中相对重要的特征指标，皆由留一法进行交叉验证。结果：通过标准判别分析，基地选材测试体系对男性青少年运动员初始案例进行分类的正确率为11~12岁的77.0%，13~14岁的51.2%，15~16岁的60.6%，以及17~18岁的77.4%，经交叉验证后的正确分类率分别降为48.0%、36.5%、40.4%和63.2%；对女性青少年运动员初始案例进行分类的正确率为11~12岁的61.7%、13~14岁的54.0%、15~16岁的61.1%和17~18岁的90.1%，交叉验证后的正确分类率分别降为31.6%、32.5%、37.3%和71.8%。通过步进式判别分析，有助于项目正确定位的特征指标有男运动员11~12岁的肩宽和小腿长A，13~14岁的下肢长B、大腿围、肺活量和背力，15~16岁的下肢长B、小腿围、大腿围和背力，以及17~18岁的身高、胸围和背力；女运动员的项目定位特征指标为11~12岁的小腿长A和肺活量，13~14岁的体重、指距、下肢长B和背力，15~16岁的下肢长B、背力和皮褶厚度和，以及17~18岁的身高、体重、小腿围、皮褶厚度和与背力。结论：基地选材测试指标体系对青少年运动员的运动项目定位表现出中到高的有效性，会受到年龄和项目的影响。下肢长B和背力指标在青春中后期表现出较强的运动项目区分能力，小腿长A指标则在青春前期表现出区分优势，可作为运动项目定位时的特征指标。     

我国青少年男子足球运动员特征性运动自信心发展特点的研究

运用文献资料调研、专家访谈、心理测量和数理统计等方法，对我国358名青少年男子足球运动员特征性运动自信心的发展特点进行了全面研究。结果表明：17～20岁高年龄组运动员的特征性运动自信心水平好于12～16岁的低年龄组运动员，且有非常显著性差异；优秀组运动员的特征性运动自信心水平好于一般组，且差异非常显著；场上不同位置的青少年男子足球运动员特征性运动自信心水平没有差异；运动员在少年时期，随着年龄的增长，他们的特征性运动自信心发展变化不大。但在少年向成年过渡这个时期，随着年龄的增长，运动员的特征性运动自信心发展变化较大，且呈逐渐增强趋势；我国青少年男子足球运动员特征性运动自信心的影响因素主要由心理优势、竞技能力、社会榜样、战略与思维决策、价值观、裁判影响、经济务件和文化水平等因子组成。     

振动训练对35～49岁和50～65岁女性骨密度与平衡能力的影响

目的:探讨全身振动训练对女性骨密度和平衡能力的影响。方法:采用随机对照研究,将入选的27名受试者按是否绝经分为未绝经组(35~49岁)和绝经组(50~65岁),组内随机分为振动训练组和对照组。振动训练组进行频率35Hz,振幅2mm,3次/周,10min/次,共8周全身振动干预。8周后,观察两组L2-L4骨密度、股骨颈骨密度、下肢肌力、膝关节活动度和平衡能力变化。结果:1训练组腰椎L2-L4BMD和股骨颈BMD都有不同程度的提高,提高幅度在0.83%~3.83%,其中50~65岁组股骨颈BMD提升最为明显;而对照组则均有不同程度的下降。两个部位BMD,35~49岁组高于50~65岁组,且存在显著性差异。2训练组下肢肌力、膝关节活动度和抗骨折能力均有不同程度提升,其中下肢肌力提高最为明显,35~49岁组下肢肌力提升36%,50~65岁组提升16%,存在显著性差异。3训练组前庭系统、本体感觉和综合平衡能力显著提高,对照组则存在不同程度的下降。结论:1全身振动干预,对抗女性骨量流失具有显著疗效,可以提高腰椎与股骨的BMD。且对股骨BMD的改善更为显著。2适宜的振动刺激不仅适用于改善骨量丢失的绝经后妇女,同样适用于骨量正常的健康年轻女性。3全身振动训练能有效提高女性下肢肌力,改善膝关节活动度,提升股骨颈抗骨折能力。且对年轻女性的刺激效果更为明显。4全身振动训练对改善女性前庭系统效果显著,进而提升综合平衡能力。     

运动训练对女子青少年体脂分布的影响

采用皮褶测定、指标计算、测定脂肪组织在体内的分布指数等方法，对２４０名初潮前后女子专项运动员和非专项运动员脂肪分布状况以及运动、性成熟对身体成分的影响进行了研究。结果表明，１３～２０岁女青少年运动员初潮后身高、体脂％和脂肪重量明显大于非运动员组，而体重、主脂体重则明显低于非运动员组；运动员组的脂肪分布主要在外周和下肢，而非运动员组中枢和外周、上肢和下肢的脂肪分布基本相近。     

我国青少年女子羽毛球运动员专项运动能力综合评估方法研究

为构建我国青少年女子羽毛球运动员专项运动能力评估方法体系，以我国羽毛球传统强队的青少年女子羽毛球运动员为测试对象，采用文献资料法、问卷调查法、测试法及数理统计法，对运动员的专项运动能力评价指标进行了研究。研究认为，青少年女子羽毛球运动员专项运动能力评价指标包括：第一是快速伸缩复合能力，其中上肢测试指标以45 s(20 kg)卧推，下肢测试指标为立定跳远；第二是多方向变向加速能力，测试指标为持拍四角跑；第三和第四分别是能量系统发展的基础耐力和速度耐力，测试指标分别为1 500次双摇跳绳和400 m×5组间歇跑；第五是核心区力量发展，测试指标为45 s悬垂举腿；第六是上肢专项动作整合能力，测试指标为1 min对墙击球为主。研究结果可以为我国青少年女子羽毛球运动员专项运动能力评估、训练和运动员的选材提供了科学依据。     

上海市10～18岁女青少年运动员生长发育与15 s无氧功特点及相关性分析

目的：探讨女青少年运动员生长发育与15S无氧功特点及其相关关系．对象和方法：以650名上海市10-18岁女运动员为对象,分别测试身高、体重、体脂率、肌肉量、瘦体重和立定跳远．并采集15S无氧功率自行车的最大功率、平均功率、最大转速、最大转速出现时间等指标,分析其特点及相关性、结果：上海市女青少年运动员身高及体重在10-13岁、最大和平均功率在㈤～15岁增长最快,15岁后趋于稳定,瘦体重、体重和肌肉与功率的相关性依次降低、结论：对女青少年运动员速度力量的训练要在15岁之前,评价女青少年运动员磷酸原代谢能力时最好使用瘦体重相对功率。     

Power training in elite young soccer players: Effects of using loads above or below the optimum power zone

ABSTRACT

This study aimed to examine the effects of two jump squat (JS) training programs involving different loading ranges in under-20 soccer players during a preseason period. Twenty-three elite young soccer players performed sprint speed (at 5-, 10-, and 20-m), change-of-direction (COD) speed, JS peak-power (PP), and countermovement jump (CMJ) tests pre and post four weeks of training. Athletes were pair-matched in two groups according to their optimum power loads (OPL) as follows: lower than OPL (LOPL; athletes who trained at a load 20% lower than the OPL) and higher than OPL (HOPL; athletes who trained at a load 20% higher than the OPL). Magnitude-based inferences were used to compare pre- and post-training measures. Meaningful increases in the PP JS were observed for both groups. Likely and possible improvements were observed in the 5- and 10-m sprint velocity in the LOPL group. Meanwhile, possible and likely improvements were observed in the CMJ, 5- and 10-m sprint velocity, and COD speed in the HOPL group. Overall, both training schemes induced positive changes in athletic performance. Soccer coaches and sport scientists can implement the JS OPL-based training schemes presented here, either separately or combined, to improve the physical performance of youth soccer players.     

负重深蹲与保加利亚蹲对冰球运动员专项移动能力影响的实验研究

目的：探讨负重深蹲练习与保加利亚蹲练习两种不同的下肢力量训练方式对冰球运动员专项移动能力的影响,并比较两种训练方式对提升冰球运动员滑行能力的差异。方法：将18名U16冰球运动员随机分为保加利亚蹲组和负重深蹲组,对其训练前后冰上30米滑行、冰上重复冲刺、8字滑行以及陆地30米跑、立定三级跳、侧跨跳、Y-Balance成绩变化进行测试。结果：两种下肢力量训练方式均可提高冰球运动员的冰上滑行能力、下肢爆发力及下肢平衡能力。在冰上滑行能力方面,保加利亚蹲组冰上重复冲刺能力提高优于负重深蹲组,具有显著性差异,冰上8字滑行速度两组间不存在显著性差异;在下肢爆发力方面,保加利亚蹲组30米冲刺跑成绩显著优于负重深蹲组。在下肢Y-Balance测试方面,两组不具有显著性差异。结论：保加利亚蹲与负重深蹲练习均可以显著提高男子U16冰球运动员的直线加速滑行能力,前者在提高重复冲刺能力方面显著优于手者,两种练习均可以提升男子U16冰球运动员的下肢爆发力与平衡能力。     

轻负荷半蹲起下肢力增加速率与各种肌肉收缩运动表现的关系

目的:探讨各种轻负荷条件下半蹲起力-时间曲线特征和力增加速率与各种肌肉收缩运动表现的相关性;分析轻负荷抗阻练习与等长、等动及纵跳动作的下肢发力特征间的内在生物力学联系。方法:募集日本筑波大学9名男子运动员,在测力台上进行不同负荷的半蹲起(Half-squat,HS)以获取地面反作用数据(GRF),进而计算出力增加速率(RFD)。进行最大负荷(>1RM)的静力收缩以测得最大力量(Fmax),进行各种纵跳练习(SJ、CMJ、RJ)以测得跳跃能力参数;采用多关节等速测力系统测取不同角速度下的膝伸展峰力矩(Peak torque,PT);采用Pearson相关系数反映不同负荷半蹲起RFD值与最大力量、跳跃能力和等速膝伸展峰力矩间的相关关系。结果:1)轻负荷半蹲起动作的平均发力时间在0.2 s以内,RFD值在0~60 ms区间内相近或相等;2)20 kg、40 kg和60 kg半蹲起RFD值与Fmax之间无相关关系(P>0.05),60 kg半蹲起RFD值与300°/s条件下的膝伸展PT存在显著性正相关(P<0.01);3)CMJ-JH和RJ-JH显著高于SJ-JH(P<0.01),而RJ的RFD值显著大于SJ和CMJ(P<0.01);4)40 kg半蹲起RFD值与SJ-JH、CMJ-JH之间存在显著性正相关(P<0.05);5)RFD与Fpeak和T-Fpeak之间分别存在显著性正相关和负相关(P<0.05),但Fpeak和T-Fpeak之间未存在相关关系(P>0.05)。结论:轻负荷半蹲起可以作为短跑、游泳等项目运动员起动力量训练手段,以减少起跑和起跳入水的反应时,强化起点技术;在20~60 kg负荷范围内,RFD值在短时间内保持相对恒定;轻负荷半蹲起在保持高输出功率的同时,具有更加高速的发力特征,可作为提高优秀运动员纵跳能力的有效练习手段。     

Bone mineral density and body composition in elite female golf and netball players

Abstract

The aim of this study was to compare bone density and body composition measurements in women participating in elite-level netball and golf, two sports with contrasting loading characteristics. Bone mineral density (BMD) and body composition were measured using dual-energy X-ray absorptiometry (DXA) in 14 state-level netball players (20.8±3.4 years), 11 single-digit handicap golf players (22.4±2.1 years) and a control group (n=18) not training for sport (22.6±3.6 years). Trunk extensor endurance and grip strength were also measured using the Sorensen test and hand-grip dynamometry respectively. Netball players had significantly higher total body, lumbar spine and hip BMD than the golf players (P<0.001) and control subjects (P<0.001). The golf players had higher BMD than the control subjects only in the lumbar spine (P<0.05). The netball players were significantly taller than the golf players and control group (P<0.01) and had a higher body mass than the control group (P<0.001). After adjustment for body height and mass, the BMD values in the netball players remained significantly higher than the control subjects at all sites (P<0.01), while the golf players had significantly higher lumbar spine BMD than the controls (P<0.05). Elite-level netball participation is associated with increased total body, hip and lumbar spine BMD, while this response was only evident in the lumbar spine in elite golf players. The contrasting loading characteristics of these sports may be reflected in the site-specific differences in BMD when compared to non-athletic control subjects.     

Effects of intermittent sprint and plyometric training on endurance running performance

PurposeThe purpose of this study was to compare the effects of intermittent sprint training and plyometric training on endurance running performance.MethodsFourteen moderately trained male endurance runners were allocated into either the intermittent sprint training group (n = 7) or the plyometric training group (n = 7). The preliminary tests required subjects to perform a treadmill graded exercise test, a countermovement jump test for peak power measurement, and a 10-km time trial. Training included 12 sessions of either intermittent sprint or plyometric training carried out twice per week. On completion of the intervention, post-tests were conducted.ResultsBoth groups showed significant reduction in weekly training mileage from pre-intervention during the intervention period. There were significant improvements in the 10-km time trial performance and peak power. There was also significant improvement in relative peak power for both groups. The 10-km time trial performance and relative peak power showed a moderate inverse correlation.ConclusionThese findings showed that both intermittent sprint and plyometric training resulted in improved 10-km running performance despite reduction in training mileage. The improvement in running performance was accompanied by an improvement in peak power and showed an inverse relationship with relative peak power.     

Vertical Jump and Leg Power Norms for Young Adults

Medical students and their spouses (N= 724) served as participants to create norm-referenced vertical jump values for active, healthy people ages 21–30. All tests were conducted and measured by thesameindividual during a campus fitness evaluation using a Vertec^TM apparatus.Jumpheightwas measured to the nearest 0.5 in.Meanjump height was similar throughout this age range within each gender. Mean jump scores, for men were 21–25 years = 22.2±3.5; 26–30 years = 21.9±3.3; and for women were 21–25 years = 14.1±2.5; 26–30 years = 14.0±2.4. From jump data, power and peak power were calculated. In this group of active individuals in their 20s, no decline in vertical jump success or power outputwas found between 21–25 and 26–30 year old groups.A table of norm-referenced values, based on percentiles,was developed that will be useful in comparing normal, active individuals in this age group to select individuals for whom leg power is an important performance measure.     

运动速度知觉信息对提高篮球长传球技术准确性的实验研究

以运动心理学有关运动知觉的基础理论为研究理论构架,采用自然实验法,从运动速度知觉训练与篮球长传球技术结合角度出发,探讨运动速度知觉训练对篮球长传球技术训练的作用。结果表明,实验组的进步幅度明显大于对照组,遮蔽练习法对提高运动速度知觉与传球的准确性有非常显著的效果。     

Height, mass and skeletal maturity of elite Portuguese soccer players aged 11-16 years

Height, mass and skeletal maturity (Fels method) were assessed in 135 elite youth soccer players aged 10.7-16.5 years (only two boys were < 11.0 years). Sample sizes, years of training and current weekly training volume by two-year age groups were: 11-12 years (n = 63), 2.6 +/- 1.0 years and 4.1 +/- 1.7 h; 13-14 years (n = 29), 3.1 +/- 1.6 years and 4.5 +/- 1.7 h; 15-16 years (n = 43), 4.7 +/- 2.4 years and 6.1 +/- 2.0 h. The oldest age group included members of the national youth team. Heights and masses were compared to US reference values, and skeletal age and chronological age were contrasted. The players were also classified as late, average ('on time') and early maturers on the basis of differences between skeletal and chronological age, with the average category including boys with skeletal ages within +/- 1 year of chronological age. The mean heights and masses of 11- to 12-year-old soccer players equalled the US reference values, while those of players aged 13-14 and 15-16 years were slightly above the reference values. The mean skeletal age approximated mean chronological age in players aged 11-12 years (12.4 +/- 1.3 and 12.3 +/- 0.5 years, respectively), while mean skeletal age was in advance of mean chronological age in the two older groups (14.3 +/- 1.2 and 13.6 +/- 0.7 years, respectively, in 13- to 14-year-olds; 16.7 +/- 1.0 and 15.8 +/- 0.4 years, respectively, in 15- to 16-year-olds). Seven boys in the oldest age group were already skeletally mature and were not included when calculating differences between skeletal and chronological age. The proportion of late maturing boys in this sample of elite soccer players decreased with increasing chronological age. Among 11- to 12-year-old players, the percentages of late and early maturing boys were equal at 21% (n = 13). Among 13- to 14-year-old players, the percentages of late and early maturing boys were 7% (n = 2) and 38% (n = 11) respectively, while among players aged 15-16 years the percentages of late and early maturing boys were 2% (n = 1) and 65% (n = 28) respectively. The results of this comparative analysis suggest that the sport of soccer systematically excludes late maturing boys and favours average and early maturing boys as chronological age and sport specialization increase. It is also possible that late maturing boys selectively drop-out of soccer as age and sport specialization increase.