首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   355篇
  免费   14篇
  国内免费   3篇
教育   34篇
科学研究   5篇
体育   253篇
综合类   80篇
  2021年   2篇
  2020年   7篇
  2019年   11篇
  2018年   6篇
  2017年   13篇
  2016年   7篇
  2015年   13篇
  2014年   15篇
  2013年   40篇
  2012年   13篇
  2011年   20篇
  2010年   15篇
  2009年   17篇
  2008年   18篇
  2007年   24篇
  2006年   19篇
  2005年   29篇
  2004年   15篇
  2003年   20篇
  2002年   16篇
  2001年   12篇
  2000年   16篇
  1999年   5篇
  1998年   4篇
  1997年   4篇
  1996年   4篇
  1994年   2篇
  1993年   1篇
  1992年   1篇
  1990年   1篇
  1989年   2篇
排序方式: 共有372条查询结果,搜索用时 29 毫秒
331.
Abstract

To develop a track version of the maximal anaerobic running test, 10 sprint runners and 12 distance runners performed the test on a treadmill and on a track. The treadmill test consisted of incremental 20-s runs with a 100-s recovery between the runs. On the track, 20-s runs were replaced by 150-m runs. To determine the blood lactate versus running velocity curve, fingertip blood samples were taken for analysis of blood lactate concentration at rest and after each run. For both the treadmill and track protocols, maximal running velocity (v max), the velocities associated with blood lactate concentrations of 10 mmol · l?1 ( v 10 mM) and 5 mmol · l?1 ( v 5 mM), and the peak blood lactate concentration were determined. The results of both protocols were compared with the seasonal best 400-m runs for the sprint runners and seasonal best 1000-m time-trials for the distance runners. Maximal running velocity was significantly higher on the track (7.57 ± 0.79 m · s?1) than on the treadmill (7.13 ± 0.75 m · s?1), and sprint runners had significantly higher v max, v 10 mM, and peak blood lactate concentration than distance runners (P<0.05). The Pearson product – moment correlation coefficients between the variables for the track and treadmill protocols were 0.96 (v max), 0.82 (v 10 mM), 0.70 (v 5 mM), and 0.78 (peak blood lactate concentration) (P<0.05). In sprint runners, the velocity of the seasonal best 400-m run correlated positively with v max in the treadmill (r = 0.90, P<0.001) and track protocols (r = 0.92, P<0.001). In distance runners, a positive correlation was observed between the velocity of the 1000-m time-trial and v max in the treadmill (r = 0.70, P<0.01) and track protocols (r = 0.63, P<0.05). It is apparent that the results from the track protocol are related to, and in agreement with, the results of the treadmill protocol. In conclusion, the track version of the maximal anaerobic running test is a valid means of measuring different determinants of sprint running performance.  相似文献   
332.
Abstract

The aim of this study was to investigate the effect of ingesting a carbohydrate-electrolyte solution, during the 90-min Loughborough Intermittent Shuttle Test, on soccer skill performance. Seventeen male soccer players ingested either a 6.4% carbohydrate-electrolyte solution or placebo solution equivalent to 8 ml · kg?1 body mass before exercise and 3 ml · kg?1 body mass after every 15 min of exercise, in a double-blind randomized cross-over design, with the trials separated by 7 days. The evening before the main trial, the participants performed glycogen-reducing exercise on a cycle ergometer (80 min at 70%[Vdot]O2max) and were then fed a low-carbohydrate meal. After a 12-h overnight fast, they performed The Loughborough Soccer Passing Test before and after every 15 min of exercise. Analysis of the combined skill test data showed a significant time effect (P = 0.001) with differences between 0–45 and 75–90 min (P < 0.05). There was a 3% reduction in skill performance from before to after exercise in the carbohydrate-electrolyte trial, whereas in the placebo trial the decrease was 14% (P = 0.07). In conclusion, skill performance during the simulated soccer activity appeared to deteriorate in the last 15–30 min of exercise. However, providing 52 g · h?1 carbohydrate during exercise showed a tendency to better maintain soccer skill performance than a taste-matched placebo.  相似文献   
333.
Abstract

The purpose of the study was to determine whether there are differences in kinematics between sprint and distance front crawl specialists when swimming at a distance pace using a six beat kick. Seven sprint and eight distance male specialists performed one maximum 400 m swim through a 6.75 m3 calibrated space recorded by six gen-locked cameras. The following variables were calculated: average swim velocity, stroke length, stroke frequency, upper limb and foot displacement, elbow angle, the shoulder and hip roll angle, duration of the stroke phases and time corresponding to particular events within the stroke cycle relative to hand entry. Differences between the groups were assessed by an independent t-test and effect size (d) calculations for each variable. The groups only differed significantly with respect to the average swim velocity, with the distance swimmers maintaining a greater velocity throughout the 400 m. However, effect sizes were moderate for elbow angle range during the pull phase (d = 0.78) and the total hip roll magnitude (d = 0.76). There was little evidence to suggest that sprint and distance swimmers using a six beat kick pattern differ in technique when swimming at a distance pace and therefore coaches should not encourage the development of different techniques between these groups.  相似文献   
334.
Abstract

Few studies have focused on the effect of posture during sprint start. The aim of this study was to measure the effect of the modification of horizontal distance between the blocks during sprint start on three dimensional (3D) joint angular velocity. Nine trained sprinters started using three different starting positions (bunched, medium and elongated). They were equipped with 63 passive reflective markers, and an opto-electronic Motion Analysis® system was used to collect the 3D marker trajectories. During the pushing phase on the blocks, norm of the joint angular velocity (NJAV), 3D Euler angular velocity (EAV) and pushing time on the blocks were calculated. The results demonstrated that the decrease of the block spacing induces an opposite effect on the angular velocity of joints of the lower and the upper limbs. The NJAV of the upper limbs is greater in the bunched start, whereas the NJAV of the lower limbs is smaller. The modifications of NJAV were due to a combination of the movement of the joints in the different degrees of freedom. The medium start seems to be the best compromise because it leads, in a short pushing time, to a combination of optimal joint velocities for upper and lower segments.  相似文献   
335.
Abstract

We examined performance, heart rate response and construct validity of the Yo-Yo IR2 test by testing 111 elite and 92 sub-elite soccer players from Norway and Denmark. VO2max, Yo-Yo IR1 and repeated sprint tests (RSA) (n = 51) and match-analyses (n = 39) were also performed. Yo-Yo IR2 and Yo-Yo IR1 performance was 41 and 25% better (P < 0.01) for elite than sub-elite players, respectively, and heart rate after 2 and 4 min of the Yo-Yo IR2 test was 20 and 15 bpm (9 and 6% HRmax), respectively, lower (P < 0.01) for elite players. RSA performance and VO2max was not different between competitive levels (P > 0.05). For top-teams, Yo-Yo IR2 performance (28%) and sprinting distance (25%) during match were greater (P < 0.05) than for bottom-teams. For elite and sub-elite players, Yo-Yo IR2 performance was correlated (P < 0.05) with Yo-Yo IR1 performance (r = 0.74 and 0.76) and mean RSA time (r = ?0.74 and ?0.34). We conclude that the Yo-Yo IR2 test has a high discriminant and concurrent validity, as it discriminates between players of different within- and between-league competitive levels and is correlated to other frequently used intermittent elite soccer tests.  相似文献   
336.
Abstract

The aim of this study was to assess the validity (Study 1) and reliability (Study 2) of a novel intermittent running test (Carminatti's test) for physiological assessment of soccer players. In Study 1, 28 players performed Carminatti's test, a repeated sprint ability test, and an intermittent treadmill test. In Study 2, 24 players performed Carminatti's test twice within 72 h to determine test–retest reliability. Carminatti's test required the participants to complete repeated bouts of 5 × 12 s shuttle running at progressively faster speeds until volitional exhaustion. The 12 s bouts were separated by 6 s recovery periods, making each stage 90 s in duration. The initial running distance was set at 15 m and was increased by 1 m at each stage (90 s). The repeated sprint ability test required the participants to perform 7 × 34.2 m maximal effort sprints separated by 25 s recovery. During the intermittent treadmill test, the initial velocity of 9.0 km · h?1 was increased by 1.2 km · h?1 every 3 min until volitional exhaustion. No significant difference (P > 0.05) was observed between Carminatti's test peak running velocity and speed at VO2max (v-VO2max). Peak running velocity in Carminatti's test was strongly correlated with v-VO2max (r = 0.74, P < 0.01), and highly associated with velocity at the onset of blood lactate accumulation (r = 0.63, P < 0.01). Mean sprint time was strongly associated with peak running velocity in Carminatti's test (r = ?0.71, P < 0.01). The intraclass correlation was 0.94 with a coefficient of variation of 1.4%. In conclusion, Carminatti's test appears to be avalid and reliable measure of physical fitness and of the ability to perform intermittent high-intensity exercise in soccer players.  相似文献   
337.
Abstract

The angiotensin converting enzyme (ACE) polymorphism is the most studied genetic marker in the field of human performance. There is a continuing debate in the literature regarding the possible association of ACE genotypes and elite athletic status. In fact, despite recent studies having identified no significant associations in athletes from mixed sporting disciplines, other researchers suggest that the insertion (I) variant may be associated with elite endurance performance, and the deletion (D) variant can be over-represented among elite sprinters. The purpose of the present study was to determine, for the first time, the association between the ACE genotypes and sprint athlete status among elite Italian gymnasts. To test this hypothesis, we assessed 33 elite Italian gymnasts (17 males, 16 females) and a control group of 53 (31 males, 22 females) unrelated sedentary individuals. DNA was extracted from each participant using a buccal swab and the ACE I/D polymorphism was determined using PCR while different amplified fragments were detected by electrophoresis using agarose gel and ethidium bromide staining. The ACE genotypes and allele frequencies among gymnasts (DD, ID, II=0.39, 0.48, 0.12, respectively; D allele=0.64) were not significantly different from those of Italian sedentary controls (DD, ID, II=0.39, 0.45, 0.15, respectively; D allele=0.62). However, the frequencies of our control group were similar to those observed in a sample of Italian sedentary individuals, and different to those of the general Caucasian population reported by other authors. Furthermore, the frequencies of our control group did not differ from those reported in other association studies involving elite sprint athletes. Our results suggest a lack of association between the ACE I/D polymorphism and elite gymnastics performance in Italians.  相似文献   
338.
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   
339.
胡垚 《体育科技文献通报》2012,20(8):46+93-46,93
世界体育竞技水平不断发展的今天,短跑技术更新和短跑技术的发展是提高短跑运动成绩的重要因素。在现代短跑运动技术中的“后扒式”着地技术和“屈蹬式”短跑技术已成为现代短跑技术中的重要技术特征;“髋动力”学说;这三种主要的短跑技术在现代短跑技术中起着举足轻重的作用。  相似文献   
340.
通过对我国短距离速度滑冰项目长期的观察和调研,对目前我国短距离速度滑冰项目专项训练方法的现状进行了总结,认为专项体能训练方面长期存在着绝对速度练习多,对速度耐力训练没有给予更多的关注,速度训练与耐力训练脱节;专项技术训练长时间在低强度下进行,当速度变快或机体疲劳时,就很难保持技术,动作变形较严重等问题。提出在有氧训练中融入技术、力量的内容和要求,使耐力与技术、耐力与力量有机结合;强化力量训练的协调性、系统性和全面性,更加注重运动员力量训练的技术是否正确、神经肌肉是否充分调动、肌肉的发力特点是否更具有协调性和专项性;注重负荷的监控,科学控制训练的进程等改进与发展建议。为构建具有我国特色的专项训练方法和手段提供理论支撑,为提高速滑运动员竞技能力提供科技保障。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号