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1.
The aim of this study was to determine the effects of 7 weeks of high- and low-velocity resistance training on strength and sprint running performance in nine male elite junior sprint runners (age 19.0+/-1.4 years, best 100 m times 10.89+/-0.21 s; mean +/- s). The athletes continued their sprint training throughout the study, but their resistance training programme was replaced by one in which the movement velocities of hip extension and flexion, knee extension and flexion and squat exercises varied according to the loads lifted (i.e. 30-50% and 70-90% of 1-RM in the high- and low-velocity training groups, respectively). There were no between-group differences in hip flexion or extension torque produced at 1.05, 4.74 or 8.42 rad x s(-1), 20 m acceleration or 20 m 'flying' running times, or 1-RM squat lift strength either before or after training. This was despite significant improvements in 20 m acceleration time (P < 0.01), squat strength (P < 0.05), isokinetic hip flexion torque at 4.74 rad x s(-1) and hip extension torque at 1.05 and 4.74 rad x s(-1) for the athletes as a whole over the training period. Although velocity-specific strength adaptations have been shown to occur rapidly in untrained and nonconcurrently training individuals, the present results suggest a lack of velocity-specific performance changes in elite concurrently training sprint runners performing a combination of traditional and semi-specific resistance training exercises.  相似文献   

2.
This study investigated the effect of low- and high-velocity resistance training on isokinetic peak torque and anaerobic power output. Eighteen male varsity oarsmen were blocked on peak knee extension torque at 3.14 rad s-1 and assigned to a high-velocity resistance training group (HVR), a low-velocity resistance training group (LVR) or a control group. Subjects trained four times a week for 5 weeks. Each training session included three circuits of 12 stations using variable-resistance hydraulic equipment. The HVR training significantly improved peak torque (P less than 0.05) in knee extension and flexion at 2.61, 3.14, 3.66 and 4.19 rad s-1. The LVR training produced significant improvements (P less than 0.05) in peak torque for knee extension and flexion at 0.52, 1.05, 1.57 and 2.61 rad s-1. High positive correlations were found between peak torque and anaerobic power outputs for all groups. However, no significant changes occurred in 15 s power output, average 90 s power output or peak blood lactate in either training group. These results indicate that velocity-specific strength training does not necessarily improve anaerobic power output in a different exercise mode despite the high positive correlation between isokinetic strength and anaerobic power output.  相似文献   

3.
跳远运动员髋关节振动力量训练效果的研究   总被引:1,自引:1,他引:0  
对10 名跳远专项二级运动员进行振动力量训练。研究表明:在刺激频率为30~35Hz,加速度25~30 m/s2 条件下,经过8 周系统的振动力量 训练,试验组髋关节的屈伸肌群与对照组屈肌肌群最大功增长都非常明显,表现出髋关节屈肌最大功比试验前有显著性地提高,试验组髋关节 屈伸肌最大功增长幅度比对照组屈伸肌最大功幅度大。试验组髋关节伸肌对照组屈伸肌峰力矩前4 周比后4 周增长幅度大,后4 周增长幅度有 所减缓,试验组后4 周髋关节屈伸肌峰力矩增长幅度比对照组高。髋关节伸肌相对峰力矩力量增长幅度比屈肌要大。  相似文献   

4.
Abstract

Sixty-two elite adolescent (age: 16.39 ± 1.62 yrs) female track and field athletes volunteered to be measured isokinetically for peak torque of the leg flexors and extensors. The sample included 16 throwers, 11 jumpers, 12 middle-distance runners (> 400 m), and 23 sprinters. A Cybex II isokinetic dynamometer was used to measure dominant leg strength at 180°/sec. One-way ANOVA revealed significant between group differences for absolute flexion and extension (Nm), extension/body weight (Nm/Kg), and extension/lean body weight (Nm/Kg). Scheffe post-hoc comparisons showed that, for absolute leg extension strength, throwers were stronger than middle-distance runners (by 54.4%), sprinters (35.6%), and jumpers (23.6%). For absolute leg flexion movements, throwers were stronger than middle distance runners (37.4%) and sprinters (32.1%). Jumpers had greater extension peak torque values than middle-distance runners relative to body weight (14.0%), and throwers were stronger than middle-distance runners for extension/lean body weight (14.9%)). No other comparisons were significant. However, when strength was expressed relative to body weight or lean body weight, there were few differences between events for flexion or extension. Given that absolute strength scores were correlated with body weight and lean body weight, peak torque/body weight or peak torque/lean body weight may be more sensitive than absolute values as indicators of underlying factors (such as training status or fiber type composition) responsible for the differences in muscular strength between groups.  相似文献   

5.
青少年男子短跑运动员膝关节等速肌力特征研究   总被引:14,自引:0,他引:14  
目的:通过对36名二级青少年男子短跑运动员双侧膝关节进行等速测试,探析青少年短跑运动员膝关节向心屈伸肌群的生物力学特性.为运动训练、科学选材及临床康复等提供理论依据。方法:利用Kinitech等速康复肌力测试系统对青少年男子短跑运动员膝关节屈伸肌群进行等速测试。结果:青少年男子短跑运动员双侧膝关节屈伸峰力矩随测试速度的增加呈递减趋势,且膝伸肌大于膝屈肌(P〈0.05),峰力矩屈伸比(V/E)随给定测试速度的增加呈递增趋势;最大功率随测试速度的增大而增加,同一测试速度下屈、伸肌群最大功率无明显差异,左、右侧相比也无显著性差异(600/s伸肌除外);屈伸肌群达峰力矩的角度(APT)表现为伸肌角度明显低于屈肌角度,随速度增加左右两侧膝关节达峰力矩的角度无显著差异:双侧膝关节屈伸肌群达峰力矩的时间(TPT)随测试速度的增加而减小,同一测试速度下伸肌达峰力矩的时间大于屈肌;右侧膝关节屈肌相对峰力矩(PT/BM)与下肢形态学指标表现出不同程度的正相关。结论:青少年男子短跑运动员膝关节峰力矩变化规律与成年人相一致,但左右侧膝关节屈伸肌群做功能力发展不平衡,屈伸肌群运动达峰力矩角度、达峰力矩的时间存在显著差异。  相似文献   

6.
目的:分析浙江师范大学投掷训练队优秀运动员腰背肌的生物力学特征,探讨投掷运动员的成绩与腰背屈伸肌群力量的关系,为投掷训练和易受伤部位的预防提供理论依据。方法:利用德国Isomed2000等速肌力测试系统进行核心力量等速肌力测试,测试严格按照Isomed2000等速测试系统使用手册的要求进行操作。结果:优秀投掷运动员腰背屈伸肌群等速向心收缩峰力矩随测试速度(30°/s~180°/s)的增加大体呈递减趋势,且随着角速度的增大,优秀投掷运动员的腰背屈伸肌群等速向心收缩峰力矩下降幅度(斜率K:伸-0.884小于屈-0.655)比普通人(K:伸-0.275小于屈-0.035)小,且优秀投掷运动员伸肌最大峰力矩的下降幅度要比屈肌小;在角速度为30°/s到120°/s时,最大功率随着给定角速度的增大而增大,在180°/s时又有所减小;腰背屈伸肌群峰力矩的角度在30°/s到180°/s时伸肌55.5°~58°大于屈肌的54.5°~56.25°,随着角速度的增大,大体呈上升趋势,在30°/s时峰力矩角度最小。  相似文献   

7.
This study examined whether avoiding or experiencing exercise-induced muscle damage (EIMD) influences strength gain after downhill walking training. Healthy young males performed treadmill downhill walking (gradient: ?28%, velocity: 5 km · h?1 and load: 10% of body mass) 1 session per week for four weeks using either a ramp-up protocol (n = 16), where exercise duration was gradually increased from 10 to 30, 50 and 70 min over four sessions, or a constant protocol (n = 14), where exercise duration was 40 min for all four sessions. Indirect markers of EIMD were measured throughout the training period. Maximal knee extension torque in eccentric (?1.05 rad·s?1), isometric and concentric (1.05 rad·s?1) conditions were measured at pre- and post-training. The ramp-up group showed no indications of EIMD throughout the training period (e.g., plasma creatine kinase (CK) activity: always <185 U · L?1) while EIMD was evident after the first session in the constant group (CK: peak 485 U · L?1). Both groups significantly increased maximal knee extension torque in all conditions with greater gains in eccentric (ramp-up: +19%, constant: +21%) than isometric (+16%, +15%) and concentric (+12%, +10%) strength without any significant group-difference. The current results suggest that EIMD can be avoided by the ramp-up protocol and is not a major determinant of training-induced strength gain.  相似文献   

8.
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。  相似文献   

9.
Resisted sprint training consists of performing overloaded sprints, which may produce greater effects than traditional sprint training. We compared a resisted sprint training with overload control versus an unresisted sprint training program on performance in soccer players. Eighteen elite athletes were randomly assigned to resisted (RST) or unresisted sprint training protocol (UR). Before and after a 6-week training period, sprinting ability, change of direction speed (COD), vertical jumps (SJ and CMJ), mean power (MP) and mean propulsive power (MPP) at distinct loads were assessed. Both groups improved sprinting ability at all distances evaluated (5m: UR = 8%, RST = 7%; 10m: UR = 5%, RST = 5%; 15m: UR = 4%, RST = 4%; 20m: UR = 3%, RST = 3%; 25m: UR = 2%, RST = 3%;), COD (UR = 6%; RST = 6%), SJ (UR = 15%; RST = 13%) and CMJ (UR = 15%; RST = 15%). Additionally, both groups increased MP and MPP at all loads evaluated. The between-group magnitude-based inference analysis demonstrated comparable improvement (“trivial” effect) in all variables tested. Finally, our findings support the effectiveness of a short-term training program involving squat jump exercise plus sprinting exercises to improve the performance of soccer players.  相似文献   

10.
Abstract

In soccer, strength, power and speed are very important because of the large number of power actions performed during the game. Therefore, the aim of this study was to examine the influence of periodised strength training for power performance more than 2 years. In this study, 134 elite youth soccer players were recruited from two youth training centres. The cohorts were arranged as follows: A (under 19 years), B (under 17 years) and C (under 15 years). The participants in each cohort were divided into two groups. One group (Strength training group [STG]) was subjected to regular soccer training in addition to strength training twice a week for 2 years. The other group (Control group [CG]) completed only the regular soccer training. The strength training was periodised with hypertrophy and intramuscular coordination blocks. For strength training, both the front squat and the back squat were performed once a week. The subjects were tested on the one-repetition maximum (1RM) of the front and back squat and a linear sprint over 30 m. There was significantly better performance from the STG on 1RM (p <0.001). In the sprint, the STG displayed significantly better improvements (p <0.05 to p <0.001) of up to 6%. The effects of strength training are reflected in the sprint performance. Therefore, it seems beneficial for youth to perform strength training to exploit the reserve capacity in sprint performances.  相似文献   

11.
This study aimed to compare the effect of 6 weeks of resistance training or combined resistance training and change of direction exercises on physical performance and motor skills in futsal players. Thirty-four futsal players were divided into full squat group (SG, n = 12), combined full squat and change of direction exercises group (S+CDG, n = 12) and control group (CG, n = 10). The resistance training for SG consisted of full squat with low load (~45–58% 1RM) and low volume (4–6 repetitions), whereas the S+CDG performed the same resistance training program combined with loaded change of direction. Sprint time in 10 and 20 m, change of direction test, countermovement vertical jump (CMJ) height, maximal strength and force–velocity relationship in full squat exercise, kicking speed ball (BSmean) and repeated sprint ability (RSAmean) were selected as testing variables. Both experimental groups showed significant improvements for CMJ, BSmean and all strength parameters. Only SG resulted in significant sprint gains, whereas S+CDG also achieved significant improvements in RSAmean. The CG remained unchanged after training period. No significant differences were found between both experimental groups. These findings suggest that only 12 sessions of either lightweight resistance training alone, lifting the load at maximal intended velocity or combined with change of direction exercises is enough to improve several physical and skills capacities critical to futsal performance in adult players.  相似文献   

12.
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。  相似文献   

13.
Abstract

The aim of the present study was to examine the relationships between muscle cross-sectional area (CSA) and muscular strength in terms of knee extension and flexion, hip extension and flexion, and hip abduction and adduction among well-trained soccer players. Fourteen university soccer players participated in the study, who had previously been divided into two groups based on ability (Group A: above-average ability; Group B: average ability). Maximal isokinetic and concentric muscular strength was measured in knee extension/flexion, hip extension/flexion and hip abduction/adduction using an isokinetic dynamometer at 1.57 and 4.19 rad·s?1 (3.14 rad·s?1) in both the dominant and non-dominant leg. The CSAs of the thigh, gluteus muscles and iliopsoas muscles were calculated based on magnetic resonance imaging. There was no significant difference between the two groups in muscle CSA and isokinetic strength. Although there were some statistically significant differences between the dominant and non-dominant leg in terms of CSA and strength (P<0.05–0.01), these were small and negligible. Apart from a non-significant relationship between the CSAs of the adductor muscles and hip adductor strength (r<0.26, n.s.), the CSA of the other muscle groups correlated with maximal isokinetic strength (r=0.38–0.64, P<0.05). These results suggest that no difference in muscle characteristics (in terms of muscle CSA and strength) was apparent among well-trained soccer players, even between the dominant and non-dominant leg. There is also a case that the anatomical function of a single (or group of) muscle(s) may not be reflected by the strength—CSA relationship depending on the movements (such as hip adduction-adductor muscle CSA). Thus, further studies are required to develop methods to assess neuromuscular function in relation to muscle morphology among soccer players.  相似文献   

14.
Abstract

We compared starters and non-starters for various isokinetic strength variables in elite women’s soccer players. A convenience sample of 10 starters (mean ± s; age = 20 ± 2 years; height = 170 ± 4 cm; body mass = 65 ± 5 kg) and 7 non-starters (age = 20 ± 1 years; height = 164 ± 3 cm; body mass = 63 ± 4 kg) performed maximal voluntary muscle actions of the leg extensors (concentric) and flexors (eccentric) on an isokinetic dynamometer in order to measure concentric peak torque for the leg extensors, eccentric peak torque for the leg flexors, and the functional hamstrings:quadriceps (H:Q) ratio at 1.047 rad · s-1 and 4.189 rad · s-1 concentric peak torque for the leg extensors was not different between starters and non-starters. However, it was greater at 1.047 rad · s-1 than at 4.189 rad · s-1 in both groups. Eccentric peak torque for the leg flexors was greater for the starters versus non-starters at 4.189 rad · s-1. Eccentric strength of the leg flexors at fast movement velocities may be used as an effective physiological profile and may discriminate between playing status in elite women’s soccer players.  相似文献   

15.
Abstract

In this study, we evaluated the peak torque, functional torque ratios, and torque curve profile of the shoulder rotators in overhead athletes with impingement symptoms so as to examine possible alterations in response to sports training and shoulder pain. Twenty-one overhead athletes with impingement symptoms were compared with 25 overhead athletes and 21 non-athletes, none of whom were symptomatic for impingement. The participants performed five maximal isokinetic concentric and eccentric contractions of medial and lateral shoulder rotations at 1.57 rad · s?1 and 3.14 rad · s?1. Isokinetic peak torque was used to calculate the eccentric lateral rotation-to-concentric medial rotation and the eccentric medial rotation-to-concentric lateral rotation ratios. An analysis of the torque curve profiles was also carried out. The eccentric lateral rotation-to-concentric medial rotation torque ratio of asymptomatic athletes was lower than that of non-athletes at both test velocities. The concentric medial rotation isokinetic peak torque of the asymptomatic athletes, at 3.14 rad · s?1, was greater than that of the non-athletes, and the peak appeared to occur earlier in the movement for athletes than non-athletes. These findings suggest that there may be adaptations to shoulder function in response to throwing practice. The eccentric medial rotation-to-concentric lateral rotation torque ratio was altered neither by the practice of university-level overhead sports nor impingement symptoms.  相似文献   

16.
An analysis system for barbell weightlifting exercises is proposed to record reliable performance and neuromuscular responses. The system consists of surface electromyography (sEMG) synchronized with electrogoniometry and a barbell position transducer. The purpose of this study was to establish the reliability of the three components of the system. Nine males (age 28.9 ± 4.8 years, mass 85.7 ± 15.1 kg) performed squat exercise at three loads on three separate trial days. A data acquisition and software system processed maximal knee angle (flexion), mean power for the concentric phase of squat exercise, and normalized root mean square of the vastus lateralis. Inter-trial coefficients of variation for each variable were calculated as 5.3%, 7.8%, and 7.5% respectively. In addition, knee joint motion and barbell displacement were significantly related to each other (bar displacement (m) = 1.39-0.0057 × knee angle (degress), with goodness-of-fit value, r2 = 0.817), suggesting knee goniometry alone can represent the kinematics of a multi-joint squat exercise. The proven reliability of the three components of this system allows for real-time monitoring of resistance exercise using the preferred training methods of athletes, which could be valuable in the understanding of the neuromuscular response of elite strength training methods.  相似文献   

17.
The aims of this study were to determine how custom-fit compression shorts affect athletic performance and to examine the mechanical properties of the shorts. Ten male and 10 female track athletes on a university's nationally competitive track team, specializing in sprint or jump events, participated in the study. Testing utilized the compression shorts with loose-fitting gym shorts as the control garment. Several significant effects were revealed for the custom-fit compressive garment. Although 60?m sprint time was not affected, hip flexion angle was reduced. Skin temperature increased more and at a faster rate during a warm-up protocol. Muscle oscillation was decreased during vertical jump landing. Countermovement vertical jump height increased when the participants were wearing the custom-fit compression garment. In materials testing, the elasticity of the compressive garment provides increased flexion and extension torque at the end range of extension and flexion, respectively, and may assist the hamstrings in controlling the leg at the end of the swing phase in sprinting. The compressive garment significantly reduced impact force by 27% compared with American football pants alone. Through various mechanisms, these findings may translate into an effect on athletic performance and a reduction in injuries.  相似文献   

18.
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.  相似文献   

19.
The purpose of this study was to assess the effect of periodized resistance training on accelerative sprint performance. Sixteen physically active men participated in a randomized controlled study. An experimental group (n = 10) completed an 8-week periodized resistance training intervention, while a control group (n = 6) did not train. Pre- and post-training measures of 20-m straight-line sprint time, including a 10-m split, maximum strength, and explosive strength, were recorded. Flight time, stance time, stride length, and stride frequency were quantified from digitized video recordings of the first three strides of the 20-m sprint. Resistance training resulted in significant increases in maximum strength (parallel back squat: 19%) and explosive strength (6-10%). However, both groups increased 0-10 m sprint times (experimental group = 6%; control group = 3%) while 10-20m times were reduced (experimental group = 7%; control group = 4%), highlighting the mechanical differences between the distinct sprint phases. The change during the 0-10m interval was accompanied by a reduction in stride frequency during the first three strides. Strength coaches should be aware that the potential benefits of increased muscular strength during short sprints are likely to be affected by mechanical specificity and that improvements in sprinting performance may not occur immediately after a period of resistance training.  相似文献   

20.
结合训练实践,运用ISOMED2000等速测试仪对我国男子散打主力队员膝、肘关节屈伸肌群肌力特征进行测试与分析。结论:不同等级散打运动员肘关节屈伸肌群等速向心、离心收缩、膝关节伸肌群等速离心收缩相对峰力矩值在60°/s、180°/s时具有显著性差异(P<0.05);膝关节屈伸肌群等速向心收缩、屈肌群离心收缩相对峰力矩值在各角速度下具有显著性差异(P<0.05);不同等级散打运动员肘、膝关节屈伸肌群等速向心收缩在300°/s、离心收缩在240°/s时达到力矩梯度最大值,且差异显著。说明基础力量、中快速力量及快速动作爆发力能较好地反映专项运动水平,相对峰力矩、力矩梯度数值越大,专项水平越高。  相似文献   

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