Effects of Acute Exercise on Long-Term Memory     

Jeffrey D. Labban  Jennifer L. Etnier 《Research quarterly for exercise and sport》2013,84(4):712-721

In this study, we tested the effect of acute exercise on long-term memory, specifically the timing of exercise relative to the memory challenge. We assessed memory via paragraph recall, in which participants listened to two paragraphs (exposure) and recounted them following a 35-min delay. Participants (n = 48) were randomly assigned to one of three groups: exercise prior to exposure, exercise after exposure, or no-exercise. Exercise consisted of 30 min on a cycle ergometer, including 20 min at moderate intensity. Only the exercise-prior group recalled significantly more than the control group (p < .05). Differences among the exercise groups failed to reach significance (p = .09). Results indicated that acute exercise positively influenced recall and that exercise timing relative to memory task may have an impact on this effect.  相似文献   

‘The finances stagger these fellows’: the Great American Bicycle Trust, 1899–1903     

Bruce D. Epperson 《国际体育史杂志》2013,30(18):2633-2652

Between 1895 and 1904, over 1,800 separate businesses merged into approximately 150 ‘trusts’, most of them simple horizontal combinations. Less than a third succeeded. One of the more spectacular failures was the American Bicycle Company. Formed by combining 45 bicycle and cycle-parts makers, it lasted less than three years. Various theories have been advanced to explain this abysmal performance, but there appears to have been no single deterministic cause. The firm was inadequate in size and scope, poorly organised, and lacking a clear goal. Its participating owners had disparate, often contradictory, objectives. Its demise left the American industry with a decentralised structure fragmented into competing sub-industries for cycle parts, bicycle fabrication and assembly, and the distribution and marketing of completed cycles. This structure led to market dominance by component firms, minimal profits and high failure rates for cycle makers, and a low overall level of innovation.  相似文献   

Normal training response in skeletal muscle of post-infarction heart failure patients     

《European Journal of Sport Science》2013,13(2):231-239

Abstract

Congestive heart failure (CHF) patients experience reduced muscle fatigue resistance and exercise capacity. The aim of this study was to assess whether skeletal muscle in CHF patients has a normal training response compared to healthy subjects. We compared the effect of one-legged knee extensor (1-KE) endurance training in CHF patients (n=10), patients with coronary artery disease (CAD, n=9) and healthy subjects (n=13). The training response was evaluated by comparing trained leg and control leg after the training period. The fall in peak torque during 75 maximal 1-KE isokinetic contractions revealed that CHF patients were less fatigue resistant than healthy subjects in the control leg, but not in the trained leg. Peak power and peak oxygen uptake during dynamic 1-KE exercise was ~10–16% higher in trained leg than control leg. This training response was not significant different between groups. Muscle biopsies of vastus lateralis showed that fibre type composition was not different between trained leg and control leg. Capillary density was 6.5% higher in trained leg than control leg when all groups were pooled. In conclusion, the more fatigable skeletal muscle of CHF patients responds equally to endurance training compared to skeletal muscle of CAD patients and healthy subjects.  相似文献   

上海市自行车旅游开展现状及对策          下载免费PDF全文

吴迪  刘志民 《体育科研》2013,(4):12-16

主要采用文献资料法、问卷调查法、专家访谈法、数理统计法等,调查了当前上海市自行车旅游开展现状,并借鉴国外先进经验,结合自身优势,从城市发展的大格局角度分析自行车旅游今后的规划、布局,强调体育和旅游及相关产业的包容性发展,突出规划的科学性、合理性,注重自行车旅游业发展的可持续性,并提出发展对策。  相似文献   

自行车运动员固定功率车测试中的肌电分析          下载免费PDF全文

郭红生  王乐军  龚铭新  司虎克 《体育科研》2013,34(1):71-74

通过实验测试方法,对优秀中长距离自行车运动员进行功率车测试及肌电研究,了解运动员在原地起动阶段的踏频及功率变化情况,以及在原地起动阶段和固定功率车进行踏蹬时．下肢各主要肌肉的激活时间与用力情况,以便掌握运动员骑行过程中主要的用力肌肉,加强训练的针对性和有效性。研究发现,股内侧肌和股外侧肌肌电信号表现明显,提示这两块肌肉可能为踏蹬主要发力肌肉。在踏蹬过程中,运动员的肌肉用力情况存在一定的差异,全能运动员与公路运动员相比,肌肉用力比较平均,肌力也相对要大  相似文献   

Optimal design of mountain bicycle based on biomechanics     

卜研  黄田  项忠霞  吴小凡  陈春 《天津大学学报(英文版)》2010,16(1):45-49

To achieve better cycling performance and vibration comfort of mountain bicycle, the optimization of frame structural parameters and rear suspension scale parameters is investigated based on biomechanics.Firstly, the quadratic sum of rider lower limb muscles stresses is presented as the evaluation criterion of muscle fatigue.By taking the criterion as the objective function, the relative positions of three pivot points of frame are optimized to ensure that the frame structural parameters match the stature o...  相似文献   

运动促进健康研究新进展   总被引：2，自引：1，他引：1       下载免费PDF全文

李之俊  向剑锋  刘欣  张勇  王晶晶  徐亮亮 《体育科研》2012,33(2):1-15

随着生活便捷性的提高,久坐不动型生活方式已经成为威胁健康的重要因素。近年来,身体活动对健康的促进作用重新引起社会的广泛关注。文章采用文献综述和实证研究的方法,对国内外学者关于步行行为和步行干预与健康关系的研究、应用加速度计监测体力活动与能量消耗的研究、运动与脂肪动员和氧化利用的研究、自行车骑行与健康促进的研究新进展做了比较全面的介绍和分析,预测以上研究领域未来发展趋势,提出了今后研究思路和研究方向建议。  相似文献   

不同运动负荷时肌肉氧含量与表面肌电图的变化特点   总被引：3，自引：0，他引：3  

王国祥 《体育学刊》2006,13(3):51-53

利用近红外光谱(NIRS)和表面肌电图(sEMG)技术,揭示自行车踏蹬运动时运动员大腿股外侧肌的氧合血红蛋白/肌红蛋白(oxy-Hb.Mb)水平及肌肉放电量的变化特征。以10名健康男子为对象,在功率自行车上先进行40 r/min,50 W的2 min准备活动后,进行阻力负荷150 W的5 min的自行车运动,踏蹬频率分别为40、60、80、100和120 r/min。结果表明:40、60、80 r/min 3组对象的股外侧肌的oxy-Hb.Mb水平分别为(104.46±6.91)%(、103.51±8.63)%和(95.14±8.73)%,各组间差异无显著性意义,而1001、20 r/min组的oxy-Hb.Mb却明显下降为(77.24±11.28)%和(43.07±9.76)%;iEMG在40至80 r/min之间呈现缓慢上升趋势,而100和120 r/min时则快速增加;各组对象的oxy-Hb.Mb水平变化和iEMG之间存在明显的相关性。因此,NIRS和表面肌电图作为特异性良好的非损伤性检测手段,能够直观地反映运动中肌肉内氧的代谢与骨骼肌的收缩活动。  相似文献   

血乳酸及心率遥测在自行车爬坡和训练台训练中的应用     

金树达 《哈尔滨体育学院学报》2006,24(2)

通过对自行车运动员爬坡训练和训练台训练中血乳酸及心率等生理生化指标的分析研究,找出提高乳酸耐受力训练水平和提高有氧能力训练水平的有效方法。  相似文献   

国家赛艇队2 000 m测功仪成绩分析   总被引：2，自引：0，他引：2  

张华杰  郑伟涛 《武汉体育学院学报》2003,37(3):62-65

测功仪成绩可以作为陆上训练及其专项能力评定的重要指标。通过对国家赛艇队冬训阶段2000m测功仪能力的测试，利用相关百分比模型，比较了国家队男女运动员之间、公开级与轻量级运动员之间存在的差异，并将测功仪成绩差异与水上成绩差异进行了比较。结果表明，考虑体重因素的测功仪相对功率能够反映运动员的实际专项水平。同时将国家队运动员与世界优秀运动员的测功仪成绩进行了比较。  相似文献