Grip and Forearm Position Effects on Tests of Static and Dynamic Upper Body Endurance

Abstract

The effects of grip and forearm position on two tests of upper body muscular endurance were investigated in 109 male subjects 18–21 years of age. Subjects were systematically presented 12 tasks: six pull-up and six straight-arm hang grip and forearm variations. Each of the six tasks for both endurance tests represented a different combination of grip (thumb over bar and thumb under bar) and forearm position (pronated, supinated and semi-pronated). Task results were analyzed utilizing 2 × 3 (grip × forearm) ANOVA with repeated measures on the two factors. Analysis of pull-up data revealed that the semi-pronated and supinated forearm positions were not statistically different from each other, but superior to the pronated condition. Results of straight-arm hang performance revealed a significant difference between grips at the semi-pronated position, with the “thumb under bar” being superior. Results for forearm positions at grips indicated a significant difference for the “thumb under bar,” with the pronated and semi-pronated positions being superior to the supinated position. For forearm positions at “thumb over bar,” the pronated condition was significantly different from the semi-pronated and supinated positions. Thumb position trends and kinesiological mechanical analysis did foster general recommendations for use of the “thumb over bar” for pull-ups and the “thumb under bar” position for the straight-arm hang.     

体操运动中双杠悬垂前摆类动作技术的分类

根据文献资料,且结合当今体操比赛的实际,对双杠悬垂前摆类动作技术进行了分类,即前摆制动类、前摆腾空类,前摆转体类。在此基础上,对每一类动作技术的特点及发展趋势,进行了论述。     

Eight-Week Traditional Mat Pilates Training-Program Effects on Adult Fitness Characteristics

We investigated responses of adult, novice practitioners (n = 9) to an 8-week traditional mat Pilates program (P) that met 1 hr/day three times/week. Classes consisted primarily of beginner and intermediate level exercises. Compared to an active control group (C; n = 13) that showed no improvements, those in P significantly (p < .05) improved relative body fat (-1.2%BF), sit-and-reach (+7.5 cm), shoulder reach (+6.9 cm), curl-up (+14 reps), and low back extension (+7 reps) scores, as well as circumferences at the waist (-2.7 cm), chest (-1.7 cm), and arm (-0.5 cm). Baseline differences were noted only for curl-ups and low back extensions, with P being lower than C. Body composition, muscular endurance, and flexibility significantly improved after 8 weeks of traditional mat Pilates.     

呼吸肌疲劳对运动能力的影响

迄今为止,人们比以往任何时候都相信,呼吸系统是影响耐力的重要因素之一。不仅剧烈的耐力练习会导致呼吸肌的疲劳,而且运动训练和比赛所导致的呼吸肌的疲劳也会影响运动员的竞技状态。因而运动员进行呼吸肌的耐力训练可以提高其耐力水平。勿庸置疑,呼吸系统的疾病可以影响运动能力,但是呼吸系统在何种程度上影响运动能力仍然有争议。     

振动训练对速滑运动员下肢肌力影响的实验研究

将振动训练运用在速滑运动员力量训练中,经过8周训练后观察训练效果,以探讨振动训练对速滑运动员下肢力量的改善效应。将16名吉林省速滑队女运动员分为两组,分别采用常规力量训练与常规训练和振动训练相结合的方式训练。实验结果表明:8周振动频率为30Hz,振幅为2mm的振动训练与常规力量训练相结合,能够有效地提高速滑运动员力量的训练效果。尽管8周振动力量训练对提高速滑运动员下肢肌群的最大力量无明显优势,但能显著性提高下肢肌群爆发力与耐力水平,同时能够有效提高速滑运动员的下蹲跳成绩。     

体院普修班男生挺身式跳远教法的实验研究

运用实验法,对两组受试对象分别采取不同的挺身式跳远教法。结果显示,改革后的教法有利于调动学生的学习积极性和主动性,且教学效果化于传统教学法。     

Effects of Aging,Grip Span,and Grip Style on Hand Strength

Abstract

This study analyzed the activity of expert table tennis players during a match, in reference to course of action theory (Theureau, 1992). Matches were videotaped, and the players' verbalizations as they viewed the tapes were collected a posteriori. The data was analyzed by (a) transcribing the players' actions and verbalizations, (b) decomposing their activity into elementary units of meaning, and (c) grouping the elementary units into larger sets. The results showed that the matches began with an inquiry into the specific features of the opponent's play. This was followed by reproducing the actions identified as effective during the inquiry. The results are discussed in relation to the role of training in expert performance.     

The effect of two different 18-week walking programmes on aerobic fitness,selected blood lipids and factor XIIa

Abstract

The purpose of this project was to evaluate the utility of low- and high-repetition maximum (RM) strength tests used to assess rowers. Twenty elite heavyweight males (age 23.7 ± 4.0 years) performed four tests (5 RM, 30 RM, 60 RM and 120 RM) using leg press and seated arm pulling exercise on a dynamometer. Each test was repeated on two further occasions; 3 and 7 days from the initial trial. Per cent typical error (within-participant variation) and intraclass correlation coefficients (ICCs) were calculated using log-transformed repeated-measures data. High-repetition tests (30 RM, 60 RM and 120 RM), involving seated arm pulling exercise are not recommended to be included in an assessment battery, as they had unsatisfactory measurement precision (per cent typical error > 5% or ICC < 0.9). Conversely, low-repetition tests (5 RM) involving leg press and seated arm pulling exercises could be used to assess elite rowers (per cent typical error ≤ 5% and ICC ≥ 0.9); however, only 5 RM leg pressing met criteria (per cent typical error = 2.7%, ICC = 0.98) for research involving small samples (n = 20). In summary, low-repetition 5 RM strength testing offers greater utility as assessments of rowers, as they can be used to measure upper- and lower-body strength; however, only the leg press exercise is recommended for research involving small squads of elite rowers.     

低聚糖运动饮料的人体饮用效果

低聚糖用于运动中补糖可提高糖的摄入量,改善运动能量供应。一种含20％糖和适量无机盐的低聚糖饮料的饮用效果在人体实验中进行了观察。3组对象(N=8)分别饮用低聚糖饮料、糖水、对照液,用70％HRmax强度蹬车至疲劳。结果显示:低聚糖饮料可使血糖维持在较高水平,并可稳定血容量、血清胰岛素、血镁、血钾和血乳酸,增加运动做功和时间。     

蛋白质组学及其技术在运动人体科学中的研究

蛋白质组学是继基因组学后的重要研究方向之一,它对于分析样本间差异蛋白图谱,揭示运动训练对机体的内在影响,寻找有意义的蛋白标志物有重要作用。对蛋白质组学数据来源、主要技术及其在运动人体科学中的应用研究进行了综述,以期进一步促进蛋白质组学研究在体育科学中的发展。     

BASES Position Statement on Guidelines for Resistance Exercise in Young People

Abstract

Despite the performance concerns of dehydration in other sports, there are currently no data on the effects of rapid weight-loss on the physical and cognitive performance of jockeys in a sport-specific context. In a randomised crossover design, eight Great Britain (GB) male licensed jockeys were assessed for chest strength, leg strength, simulated riding performance (assessed by maximum pushing frequency on a mechanical riding simulator during the final two furlongs of a simulated 2 mile race) and simple reaction time after performing 45 min of exercise, during which euhydration was maintained (Control trial) or induced 2% dehydration (Rapid Weight-Loss trial). Reductions in both chest (–13.8 ± 3.03% vs. 0.62 ± 1.04%) and leg strength (–4.8 ± 4.8% vs. –0.56 ± 2.5%) were greater in Rapid Weight-Loss compared with Control (P < 0.01 and P = 0.04, respectively). Similarly, reductions in simulated riding performance were also greater (P = 0.05) in Rapid Weight-Loss (–2.8 ± 4.0%) compared with Control (–0.07 ± 1.5%), whereas there were no significant changes (P = 0.14) in simple reaction time. We conclude that a 2% reduction in body mass, as achieved by 45 min of moderate-intensity exercise undertaken in a sweatsuit (a common method of inducing acute dehydration by jockeys), significantly impairs maximum pushing frequency during a simulated race. In addition, the observed reductions in strength may also increase the occupational hazards associated with race riding.     

阻力训练及超等长阻力训练对下肢肌肉活性和力量的影响

目的:观察阻力训练和超等长阻力训练后下肢肌肉力量变化,比较肌肉激活模式的不同.方法:将16名男性篮球运动员随机分成两组,分别实施8周下肢阻力训练和超等长阻力训练.采用3-D测力台测试训练前、后最大随意收缩值,用表面肌电记录训练前、后6次重复训练动作的胫骨前肌、腓肠肌外侧头、股直肌、股外侧肌、股二头肌的激活信号,计算积分肌电值和髋、膝、踝关节周围拮抗肌共激活.结果:两组下肢肌肉力量均显著提高,阻力训练组效果较明显.超等长阻力训练组肌肉活性显著高于阻力训练组.训练后超等长阻力训练组肌肉活性出现适应性变化,髋、踝关节拮抗肌共激活显著升高,膝关节拮抗肌共激活训练前、后没有显著性差异.阻力训练组训练前、后肌肉活性及拮抗肌共激活没有显著变化.结论:超等长阻力训练有助于提高肌肉间协调性,可以优化肌肉动作的运动策略.     

Philosophical reflections on the mission of the European College of Sport Science: Challenges and opportunities

Abstract

The European College of Sport Science (ECSS) was established in part to promote the integrated study of sports and related phenomena from multi- and interdisciplinary perspectives. There are significant and enduring philosophical, epistemological and professional challenges and opportunities that arise from this integrationist perspective. In this article, we reflect upon the challenges that have arisen in the development of sport sciences in the attempt to realize the ECSS mission. We identify three paradigmatic approaches to sports science: (1) the mechanistic; (2) the hermeneutic and (3) the critical. We critically evaluate these paradigms and their potential within the broad framework of integrationist ambitions for sports science as a scientific field.     

丙酮酸和二羟丙酮补充对机体代谢和有氧耐力的影响

丙酮酸和二羟丙酮都是糖代谢过程中的三碳化合物。长期丙酮酸和二羟丙酮补充可以降低体脂和延缓体重获得,这种变化可能与体脂消耗和热量损失上升有关。丙酮酸和二羟丙酮补充也可以改善胰岛素敏感性和降低高胆固醇膳食所致的血浆胆固醇水平。另外,长期丙酮酸和二羟丙酮补充还可以提高有氧耐力成绩,其机制可能与血糖利用率增加因而节省肌糖元有关。长期补充丙酮酸和二羟丙酮可有利于疾病预防和提高运动成绩。     

The influence of different footwear on 3-D kinematics and muscle activation during the barbell back squat in males

Abstract

The barbell back squat is commonly used by athletes participating in resistance training. The barbell squat is typically performed using standard athletic shoes, or specially designed weightlifting footwear, although there are now a large number of athletes who prefer to squat barefoot or in barefoot-inspired footwear. This study aimed to determine how these footwear influence 3-D kinematics and muscle activation potentials during the barbell back squat. Fourteen experienced male participants completed squats at 70% 1 rep max in each footwear condition. 3-D kinematics from the torso, hip, knee and ankle were measured using an eight-camera motion analysis system. In addition, electromyographical (EMG) measurements were obtained from the rectus femoris, tibialis anterior, gastrocnemius, erector spinae and biceps femoris muscles. EMG parameters and joint kinematics were compared between footwear using repeated-measures analyses of variance. Participants were also asked to subjectively rate which footwear they preferred when performing their squat lifts; this was examined a chi-squared test. The kinematic analysis indicated that, in comparison to barefoot the running shoe was associated with increased squat depth, knee flexion and rectus femoris activation. The chi-squared test was significant and showed that participants preferred to squat barefoot. This study supports anecdotal evidence of athletes who prefer to train barefoot or in barefoot-inspired footwear although no biomechanical evidence was found to support this notion.     

高温环境下混合预冷对男性中长跑运动员体温调节和有氧耐力运动表现的影响

目的:探讨高温环境下混合预冷对男性中长跑运动员体温调节和有氧耐力运动表现的影响。方法:10名男性中长跑运动员随机分为对照组(PC)5人和混合预冷组(MP)5人。2组被试在标准热身后,进行20 min预冷,PC组每5 min摄入1.5 g/kg,共7.5 g/kg的25℃运动饮料,MP组每5 min摄入1.5 g/kg,共7.5 g/kg的5℃运动饮料,并在预冷期间持续使用手部负压冷却设备CoreControlTM。预冷结束后10 min在30℃~31℃的相对湿度为57%的室外标准田径场进行5 km跑步测试。采用独立样本t检验分析5 km测试成绩和出汗率,采用双因素重复测量方差分析在不同时间点测得的核心温度、皮肤温度等数据,用Bonferroni进行两两比较,P<0.05为具有显著性差异。结果:预冷期间,预冷和时间的交互作用对胃肠温度(Tgi),体温(Tb)和生理应激指数(PSI)具有显著性差异(P<0.001,ES=2.96;P<0.001,ES=2.41;P=0.001,ES=1.6),预冷结束时MP与PC的Tgi,PSI具有显著性差异(P=0.003,P=0.001)。预冷和时间的交互作用对皮肤温度(Tsk),热量储存(HS),心率(HR)无显著性差异(P=0.975,P=0.263,P=0.071)。5 km测试期间,预冷和时间的交互作用对Tgi、Tsk、Tb、HS、PSI、HR均无显著性差异义(P>0.05),预冷对Tgi、PSI的主效应具有显著性差异(P=0.028,ES=1.68;P=0.013,ES=2.11)。MP与PC的SW无显著性差异(P=0.63)。MP与PC的5 km完成时间具有显著性差异(P=0.035)。结论:高温环境下,预冷摄入冷饮结合手部负压冷却降低运动前的核心温度和生理应激程度,能够在5 km测试期间延缓核心温度升高和生理应激程度,提高有氧耐力运动表现。     

大豆异黄酮对实验小鼠运动耐力的影响

以小鼠为研究对象,研究大豆异黄酮对小鼠运动耐力的影响。将雄性SPF级小鼠160只,体重18~22g,按体重随机分成空白对照组和0.15g/kg.BW、0.30g/kg.BW、0.60g/kg.BW3个剂量组,每组40只。小鼠经口灌胃给予大豆异黄酮30天后,分别测定负重游泳时间、血乳酸、血清尿素氮及肝糖原含量。实验结果发现大豆异黄酮高剂量组与空白对照组相比小鼠负重游泳时间明显延长,小鼠游泳前后血乳酸测定曲线下的面积、血清尿素氮明显低于空白对照组,肝糖原水平明显高于空白对照组。得出大豆异黄酮能提高小鼠运动耐力的结论。     

力量训练提升马拉松跑者耐力运动表现的研究进展及训练策略

有氧能力的高低是马拉松跑者能否取得优异成绩的关键。最大摄氧量、乳酸阈和跑步经济性是衡量运动员有氧能力和耐力运动表现的关键指标,也是长跑训练效果的核心考量。由于力量和耐力训练对机体产生不同的训练刺激,教练员和运动员很少将力量训练作为提升耐力运动表现的手段,以防止有氧能力受到负面影响。通过对大量文献梳理发现,力量训练可以在不影响机体最大摄氧量和乳酸阈值的前提下,通过改善神经肌肉功能、转换肌纤维类型以及增强肌肉肌腱刚度和利用弹性势能的能力,提高跑步经济性和无氧能力,改善运动员耐力运动表现。本文基于对力量、耐力训练的生理学适应的探讨,总结不同形式力量训练对耐力运动表现的影响与作用机制,并为马拉松选手科学安排力量训练提出建议,从而优化其耐力运动表现。     

Body Fatness and Performance Differences between Men and Women

The purpose of this study was to determine the extent to which the mean difference in performance between men and women on selected physical performance tests was related to the sex difference in body fatness. Percent total body fat (% fat) estimated from skinfold thickness measures and performances on the modified pull-up, vertical jump, 50-yard dash, and 12-minute-run tests were measured on 55 male and 55 female college students. Males had significantly less fat and performed significantly better than females on each of the performance tests. Mean differences were 8.2% fat, 20.0 modified pull-ups, 20.8 cm on the vertical jump, 1.3 seconds on the 50-yard dash, and 590 m on the 12-minute run. Linear regression equations predicting performance scores from % fat within the groups of men and women indicated that if body fatness in men and women were similar, performance differences would be reduced, on the average, by 7 modified pull-ups, 4 cm on the vertical jump, .5 seconds on the 50–yard dash, and 146 m on the 12-minute run. These expected changes in performance were 36%, 19%, 38%, and 25% of the mean sex difference in performance on the four physical performance tests, respectively. It was concluded that greater body fatness is one characteristic that partly explains why women, on the average, do not perform as well as men on strenuous tasks requiring movement of the body weight. The sex-specific difference in body fatness should be one factor considered in establishing separate occupational and athletic performance expectations for men and women.