Effects of coffee and caffeine anhydrous on strength and sprint performance     

Eric T. Trexler  Erica J. Roelofs  Katie R. Hirsch  Meredith G. Mock 《European Journal of Sport Science》2016,16(6):702-710

Caffeine and coffee are widely used among active individuals to enhance performance. The purpose of the current study was to compare the effects of acute coffee (COF) and caffeine anhydrous (CAF) intake on strength and sprint performance. Fifty-four resistance-trained males completed strength testing, consisting of one-rep max (1RM) and repetitions to fatigue (RTF) at 80% of 1RM for leg press (LP) and bench press (BP). Participants then completed five, 10-second cycle ergometer sprints separated by one minute of rest. Peak power (PP) and total work (TW) were recorded for each sprint. At least 48 hours later, participants returned and ingested a beverage containing CAF (300?mg flat dose; yielding 3–5?mg/kg bodyweight), COF (8.9?g; 303?mg caffeine), or placebo (PLA; 3.8?g non-caloric flavouring) 30 minutes before testing. LP 1RM was improved more by COF than CAF (p?=?.04), but not PLA (p?=?.99). Significant interactions were not observed for BP 1RM, BP RTF, or LP RTF (p?>?.05). There were no sprint?×?treatment interactions for PP or TW (p?>?.05). 95% confidence intervals revealed a significant improvement in sprint 1 TW for CAF, but not COF or PLA. For PLA, significant reductions were observed in sprint 4 PP, sprint 2 TW, sprint 4 TW, and average TW; significant reductions were not observed with CAF or COF. Neither COF nor CAF improved strength outcomes more than PLA, while both groups attenuated sprint power reductions to a similar degree. Coffee and caffeine anhydrous may be considered suitable pre-exercise caffeine sources for high-intensity exercise.  相似文献   

How much does lower body strength impact Paralympic running performance?     

E. M. Beckman  M. J. Connick  S. M. Tweedy 《European Journal of Sport Science》2016,16(6):669-676

Objectives: Development of evidence-based methods of Paralympic classification requires research quantifying the relative strength of association between ratio-scaled measures of impairment and athletic performance. The purpose of this study was to quantify the extent to which muscle strength affects running performance in runners with and without brain impairment. Design: Cross-sectional study. Methods: Participants were 41 male runners: 13 with brain impairments (RBI) and 28 non-disabled (NDR). All participants completed a maximal 60-m sprint and a novel battery of three lower limb isometric strength tests. Results: RBI showed significantly lower strength scores compared with NDR on the more affected side in leg flexion (176 vs. 243?N), leg extension (993 vs. 1661?N) and plantarflexion (824 vs. 1457?N). Significant differences were also seen on the less affected side in plantarflexion (1072 vs. 1508?N). RBI were significantly slower in the acceleration phase (0–15?m) (3.2?s?±?0.3?vs. 2.8?s?±?0.2) and top speed phase (30?60?m) (4.3?s?±?0.6?vs. 3.8?s?±?0.3). Correlation analysis showed stronger relationships between strength and running performance in RBI than NDR; however, the correlations were not significant. Conclusions: This study evaluated measures to assess strength for the purposes of classification and found that the measures were significantly different in RBI compared with NDR indicating the tests were able to capture strength impairment in this population. This study indicates that strength may be an important impairment type to assess in this population, as impairments of muscle strength may influence the outcome of running performance in athletes with more severe impairments.  相似文献   

Physical activity profiles and selected muscular fitness variables in English schoolchildren: A north–south divide?     

Lee Ingle  Ashlie Stephenson  Gavin R. Sandercock 《European Journal of Sport Science》2016,16(8):1187-1196

The aim of the study was to compare and contrast habitual physical activity (PA) profiles and muscular fitness in schoolchildren from northern and southern regions of England. Data were collected from two secondary schools in the north east (NE) of England. The study procedures followed methods employed by the East of England Healthy Hearts Study in 10–16-year-old boys and girls based in the south east (SE) region of England and data were compared. Habitual physical activity (PAQ-A), vertical jump test, and hand-grip (HG) strength were assessed. We converted raw scores from all assessments to age- and sex-normalised z-scores. We recruited 597 children (58% boys) in the NE and compared findings to 597 age- and sex-matched boys and girls from the SE. Boys in the SE had significantly stronger HG scores, jumped higher, were more powerful (mean peak power: 2131?W vs. 1782?W; P?P?P?相似文献   

Low-intensity electrical muscle stimulation induces significant increases in muscle strength and cardiorespiratory fitness     

Toshiaki Miyamoto  Hiroyuki Kamada  Akira Tamaki  Toshio Moritani 《European Journal of Sport Science》2016,16(8):1104-1110

The aim of this study was to investigate the effect of low-intensity exercise training using belt electrode skeletal muscle electrical stimulation on muscle strength and cardiorespiratory fitness in healthy subjects. Nineteen healthy subjects were allocated into control or intervention groups; in both groups the participants kept regular physical activity while the intervention group underwent 30 min B-SES training at 3–4 METs for four weeks. Knee extensor muscle strength and cardiorespiratory endurance during incremental exercise test were measured at baseline and after four weeks for all participants. The relative change of knee extensor muscle strength in the intervention group was significantly higher than control group (p?p?相似文献   

钢结构材料在高温(火灾)条件下的力学性能试验研究     

魏瑞演 《福建工程学院学报》2002,(1)

从基本的钢结构材料在高温下的力学性能着手 ,进行高温条件下钢结构材料的性能试验 ,建立高温下钢材的屈服强度、极限强度、弹性模量和极限应变随温度变化的力学模型 ,为高温 (火灾 )条件下钢结构的结构分析提供依据。  相似文献   

C语言中的自增/自减运算符     

孙义欣  许卫华  孟令波 《潍坊教育学院学报》2006,19(4):17-18

本文根据笔者多年的C语言编程经验,详细归纳了++/--运算符在解题过程中应注意的多个方面的事项,是对教材的一个非常有益的补充,可用于C语言教学的参考,也有助于初学者的自学。  相似文献   

对高水平男子跳高运动员专项力量训练手段的研究     

张红霞 《滨州学院学报》2006,22(6):86-88

运用文献资料法、问卷调查法、统计分析等方法,对高水平男子跳高运动员专项力量训练手段进行统计研究,遴选出常用的、功效性高的专项力量训练手段18项,并将其分为爆发力、支撑力量、起跳力量、摆动力量和腹(背)肌力量5类,为男子跳高运动员专项力量的训练提供有价值的参考.  相似文献   

把握学生思想 提高德育实效     

王定 《湖南第一师范学报》2003,3(2):35-38

教育应针对学生的思想、生活、心理、学习、行为等实际状况未进行。学生的思想动态都有其深层的形成原因，只有在此基础上才能手求出提高高校德育实效的系统化、榜样化、随机性、民主性、参与性等一般性原则。  相似文献   

篮球专项力量训练的研究     

刘革  张海灵 《牡丹江教育学院学报》2007,(3):92-93

篮球运动员的力量训练应注重弹跳力、腰背部肌肉力量、小腿肌群力量和手臂、手腕、手指力量的发展.该研究从篮球专项力量训练的理论基础、训练方法的选择、需要注意的问题等方面进行了分析,为篮球专项力量的训练提供了重要参考.  相似文献   

构建实战型服装高职教育模式     

李敏 《成都教育学院学报》2006,20(9):96-97,99

每个教育层次都应根据自己的培养目标构建独特的教育模式。服装高职学校是为服装行业第一线培养技能型人才的教育机构,应采取实战型教育模式,培养学生的艺术创造能力、实际操作能力、市场适应能力,以实现自己的教育目标。  相似文献