Rambaud O, Rahmani A, Moyen B, Bourdin M.
Biomechanics and Impact Mechanics Laboratory, Claude Bernard University Lyon 1, Lyon-South Teaching Hospital, Oullins, France. [email]orambaud@univ-lyon1.fr[/email]
The purpose of this study was to investigate the influence of upper-limb inertia on the force-velocity relationship and maximal power during concentric bench press exercise. Reference peak force values (Fpeakp) measured with a force plate positioned below the bench were compared to those measured simultaneously with a kinematic device fixed on the barbell by taking (Fpeakt) or not taking (Fpeakb) upper-limb inertia into account. Thirteen men (27.8 +/- 4.1 years, 184.6 +/- 5.5 cm, 99.5 +/- 18.6 kg) performed all-out concentric bench press exercise against 8 loads ranging between 7 and 74 kg. The results showed that for each load, Fpeakb was significantly less than Fpeakp (P < 0.0001), whereas no significant difference was found between Fpeakp and Fpeakt. The values of maximal force (F0), maximal velocity (V0), optimal velocity (Vopt), and maximal power (Pmax), extrapolated from the force- and power-velocity relationships determined with the kinematic device, were significantly underestimated when upper-limb inertia was ignored. The results underline the importance of taking account of the total inertia of the moving system to ensure precise evaluation of upper-limb muscular characteristics in all-out concentric bench press exercise with a kinematic device. A major application of this study would be to develop precise upper-limb muscular characteristic evaluation in laboratory and field conditions by using a simple and cheap kinematic device. The biomechanical and perceptual influence of chain resistance on the performance of the olympic clean.
Berning JM, Coker CA, Briggs D.
Department of Physical Education, Recreation, and Dance, New Mexico State University, Las Cruces, New Mexico, USA. [email]jberning@nmsu.edu[/email]
Proponents of chain training suggest that using chains hung from the ends of barbells rather than using conventional barbells alone enhances strength, power, and neuromuscular adaptations. The purpose of this study was to determine whether a conventional barbell with chains compared to a conventional barbell without chains would affect the performance of an Olympic Clean. The subjects were also asked regarding their perception of how chains affected their lifting. Four male and 3 female competitive weightlifters who used chains as part of their training participated in the study. The testing protocol compared the subjects' lifting 80% and 85% of their 1 repetition maximum (1RM) using conventional barbells and their lifting 80% and 85% of their 1RM using chains (75% conventional barbells + 5% chains and 80% conventional barbells + 5% chains, respectively). Video analysis evaluated the bar's vertical displacement and velocity and the rate of force production. Vertical ground reaction forces for the first-pull, unweighting, and second-pull phases of the lift were evaluated by using a force plate. After testing, the subjects completed a 2-item questionnaire asking individual perception of the effects of the chains. The results showed no significant difference for condition for any of the variables examined. In contrast, all subjects perceived that the chains required a greater effort. In conclusion, the results indicated that the addition of chains provided no greater value over lifting conventional barbells alone in the performance of the Olympic Clean, although the subjects perceived the chains to have a positive effect. The effect of strength training on three-kilometer performance in recreational women endurance runners.
Kelly CM, Burnett AF, Newton MJ.
School of Exercise, Biomedical, and Health Sciences, Edith Cowan University, Perth, Western Australia, Australia.
In this study, we investigated whether a heavy strength training program, as an additive to an endurance running program, would cause significant improvements in 3-km run time in a group of recreationally fit women when compared with endurance-only (EO) training. Sixteen women aged between 18 and 27 years of age were randomly assigned to either an EO group (n = 9) or a concurrent strength and endurance (CSE) group (n = 7). A 10-week training program for both groups consisted of an endurance running program performed three afternoons per week. The CSE group also participated in strength training on the morning of each running session. Testing was conducted pre and post training in a 3-km time trial and measured VO2peak, running economy, muscular strength (1 repetition maximum), and body composition and girth. There was a trend (P = 0.07) toward greater improvement in 3-km performance time for the CSE group (106.7 +/- 91.4 seconds) when compared with the EO group (77.3 +/- 93.0 seconds). Further, the CSE group showed an increase in strength levels when compared with the EO group. The CSE group showed significant increases (P </= 0.05) in the parallel squat and hamstring curl, and a significant increase (P </= 0.05) was also found in upper body strength for the bench press (11.9% increase) when compared with the EO group. There were no significant differences between the two groups for VO2peak, running economy, body composition, or girth measurements. This study found no negative or compatibility problems when heavy strength training was added to an endurance running program, and a nonsignificant increase in improvement for 3-km times was evident. Does a short period of lower limb strength training improve performance in field-based tests of running and agility in young professional soccer players?
Jullien H, Bisch C, Largouët N, Manouvrier C, Carling CJ, Amiard V.
Laboratoire de Recherches, E.P.S. et Conduites motrices, Adaptations et Réadaptations, Faculté des Sciences du Sport, Université de Picardie Jules Verne, Amiens, Cedex, France. [email]hugues.jullien@ca-u-picardie.fr[/email]
The present study assessed the effects of specific leg strength training (as part of a broader exercise program) on running speed and agility in young professional soccer players. Twenty-six male players (ages 17 to 19 years) were divided into 3 groups. The reference group (Re) performed individual technical work only, the coordination group (Co) performed a circuit designed to promote agility, coordination, and balance control (together with some technical work) and the Squat group (Sq) underwent 3 series of 3 squat repetitions (at 90% of the individual maximum value) and a sprint, before competition of the agility circuit and some technical work. These specific training programs were performed 5 times a week for 3 weeks. Before the experimental session and at the end of each week, all players were assessed using 4 types of tests, (agility, a shuttle test with changes of direction, and 2 sprints over 10 and 7.32 meters, respectively), with completion time being the only performance parameter recorded. Our results indicate that in the short sprints or shuttle sprint with changes in direction, lower limb strengthening did not improve performance. Performance improved in all 3 groups in the agility test but more so in the reference and coordination groups. It appears that soccer-specific training composed of exercise circuits specifically adapted to the different types of effort actually used in match play can enhance agility and coordination. Does performance of hang power clean differentiate performance of jumping, sprinting, and changing of direction?
Hori N, Newton RU, Andrews WA, Kawamori N, McGuigan MR, Nosaka K.
School of Exercise, Biomedical and Health Sciences, Edith Cowan University, Joondalup, Western Australia, Australia. [email]ghori@wais.org.au[/email]
The primary purpose of this study was to investigate whether the athlete who has high performance in hang power clean, a common weightlifting exercise, has high performances in sprinting, jumping, and changing of direction (COD). As the secondary purpose, relationships between hang power clean performance, maximum strength, power and performance of jumping, sprinting, and COD also were investigated. Twenty-nine semiprofessional Australian Rules football players (age, height, and body mass [mean +/- SD]: 21.3 +/- 2.7 years, 1.8 +/- 0.1 m, and 83.6 +/- 8.2 kg) were tested for one repetition maximum (1RM) hang power clean, 1RM front squat, power output during countermovement jump with 40-kg barbell and without external load (CMJ), height of CMJ, 20-m sprint time, and 5-5 COD time. The subjects were divided into top and bottom half groups (n = 14 for each group) based on their 1RM hang power clean score relative to body mass, then measures from all other tests were compared with one-way analyses of variance. In addition, Pearson's product moment correlations between measurements were calculated among all subjects (n = 29). The top half group possessed higher maximum strength (P < 0.01), power (P < 0.01), performance of jumping (P < 0.05), and sprinting (P < 0.01). However, there was no significant difference between groups in 5-5 COD time, possibly because of important contributing factors other than strength and power. There were significant correlations between most of, but not all, combinations of performances of hang power clean, jumping, sprinting, COD, maximum strength, and power. Therefore, it seems likely there are underlying strength qualities that are common to the hang power clean, jumping, and sprinting. 最好有个英汉对照。 这个是国外的杂志，我一个人不可能翻译这么多哦，大家看看人家的研究思路就行了，非常不错的思路 谢谢师兄，我最喜欢的就是体能训练方面的资料。 如果感兴趣，不妨做点实验研究。国外的体能训练研究非常实际，具体方法可以查看原文的。 谢谢任兄的资料^_^ 好东西，大家一起来支持！谢谢楼主，祝好人一生平安! :laugh: 中文！！！！！
回复 52# wy_5223 的帖子
呵呵，大家可以一块努力将国外的翻译出来嘛，一个人的力量太小了哦:sweating: 开学有时间翻译翻译，呵呵 大家一起讨论到时候全英文呀．
可惜全是英文，咱看不懂，特别还有一些专业术语．希望有高手能将一些专业术语翻译过来． 建议大家安装金山词霸！ 请问下，能否看到全文？ 具体哪篇？ 英文难啊，有中文的就好了。 这篇：Chronic stretching and voluntary muscle force.
LaRoche DP, Lussier MV, Roy SJ.
如能看到全文就太感谢了。