The acute testosterone,growth hormone,cortisol and interleukin-6 response to 164-km road cycling in a hot environment     

Jakob L. Vingren  Ronald G. Budnar Jr.  Amy L. McKenzie  Anthony A. Duplanty  Hui-Ying Luk  Danielle E. Levitt 《Journal of sports sciences》2016,34(8):694-699

This study investigated the acute endocrine responses to a 164-km road cycling event in a hot environment. Thirty-four male experienced cyclists (49.1 ± 8.3 years, 86.8 ± 12.5 kg, 178.1 ± 5.1 cm) participating in a 164-km road cycling event were recruited. Blood samples were collected within 0.3–2.0 h before the start (PRE: ~0500–0700 h) and immediately following the ride (POST). Samples were analysed for testosterone, growth hormone (GH), cortisol and interleukin-6 (IL-6). The temperature and humidity during the event were 35.3 ± 4.9°C and 47.2 ± 14.0%, respectively. Based on the finishing time, results for the fastest (FAST, 305 ± 10 min) and the slowest (SLOW, 467 ± 31 min) quartiles were compared. At POST, testosterone concentration was significantly (P < 0.05) lower (PRE, 20.8 ± 8.6; POST, 18.2 ± 6.7 nmol · L^?1), while GH (PRE, 0.3 ± 0.1; POST, 2.3 ± 0.3 µg · L^?1), cortisol (PRE, 661 ± 165; POST, 1073 ± 260 nmol · L^?1) and IL-6 (PRE, 4.0 ± 3.4; POST, 22.4 ± 15.2 pg · mL^?1) concentrations were significantly higher than those at PRE. At POST, GH and cortisol were significantly higher for the FAST group than for the SLOW group (GH, 3.6 ± 2.0 and 1.0 ± 0.8 µg · L^?1; cortisol, 1187 ± 209 and 867 ± 215 nmol · L^?1). Participation in an ultra-endurance road cycling event in a hot environment induced significant acute changes in concentrations of circulating hormones, with a greater augmentation of GH and cortisol in those completing the ride fastest.  相似文献   

Effects of glucose–fructose versus glucose ingestion on stride characteristics during prolonged treadmill running     

Patrick B. Wilson  Stacy J. Ingraham 《Sports biomechanics / International Society of Biomechanics in Sports》2016,15(3):270-282

Scarce research has examined the effects of carbohydrate composition on running stride characteristics. On two occasions, 14 males and 6 females completed a 120-min sub-maximal run followed by a 4-mile time trial. Participants consumed glucose (GLU) or glucose–fructose (GLU–FRU) beverages supplying 1.3 g/min carbohydrate. Substrate use, psychological affect [Feeling Scale (FS)], and stride characteristics (stride frequency, stride length, and contact time) were assessed. Effects were expressed as Cohen’s d (90% confidence limits [90% CL]). CLs for stride frequency differences at 53 min (90% CL = 0.04–0.21) and 113 min (90% CL = 0.02–0.24) did not cover 0, indicating a positive effect of GLU–FRU. However, effect sizes were small (d = 0.13) and likely-to-very-likely trivial. Energy expenditure differences at sub-maximal end were very likely trivial (d = 0.08; 90% CL = 0.00–0.17), while FS ratings were possibly higher for GLU–FRU at 50 (d = 0.19; 90% CL = ?0.10–0.48) and 110 min (d = 0.16; 90% CL = ?0.13–0.45). During the time trial, stride length was possibly higher with GLU–FRU (d = 0.13; 90% CL = ?0.08–0.33). Glucose–fructose co-ingestion has no significant effect on stride characteristics during constant-velocity running but may result in slightly higher stride length during self-paced running.  相似文献   

Ground reaction forces of Olympic and World Championship race walkers     

Brian Hanley  Athanassios Bissas 《European Journal of Sport Science》2016,16(1):50-56

Race walking is an Olympic event where no visible loss of contact should occur and the knee must be straightened until midstance. The purpose of this study was to analyse ground reaction forces of world-class race walkers and associate them with key spatiotemporal variables. Nineteen athletes race walked along an indoor track and made contact with two force plates (1000 Hz) while being filmed using high-speed videography (100 Hz). Race walking speed was correlated with flight time (r = .46, p = .049) and flight distance (r = .69, p = .001). The knee's movement from hyperextension to flexion during late stance meant the vertical push-off force that followed midstance was smaller than the earlier loading peak (p < .001), resulting in a flattened profile. Athletes with narrower stride widths experienced reduced peak braking forces (r = .49, p = .046), peak propulsive forces (r = .54, p = .027), peak medial forces (r = .63, p = .007) and peak vertical push-off forces (r = .60, p = .011). Lower fluctuations in speed during stance were associated with higher stride frequencies (r = .69, p = .001), and highlighted the importance of avoiding too much braking in early stance. The flattened trajectory and consequential decrease in vertical propulsion might help the race walker avoid visible loss of contact (although non-visible flight times were useful in increasing stride length), while a narrow stride width was important in reducing peak forces in all three directions and could improve movement efficiency.  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   

ACE基因多态性与有氧耐力运动关系研究   总被引：4，自引：0，他引：4  

甄文娟  谢盛  宋海宾 《乐山师范学院学报》2004,19(5):116-118

目前普遍认为ACE(血管紧张素转换酶)的水平和心血管的形态、功能密切相关。ACE基因的多态性是人耐力素质优劣的决定性因素之一。为了解运动员血管紧张素转换酶(ACE)基因插入或缺失(I/D）多态性情况，探讨ACE基因多态性与有氧耐力可能的关系，用聚合酶链反应(PCR)技术检测20例运动员和20例健康对照者的ACE基因多态性。结果位于ACE基因16内含子的L／D多态性经PCR扩增后呈三种基因型：纯合子插入型(II）、纯合子缺失型(DD)和杂合子插入或缺失型(ID)。耐力运动员组Ⅱ基因型和Ⅰ等位基因频率显著高于健康对照组。结果表明ACE基因可能在运动员的有氧耐力中起重要作用。  相似文献   

学校体育课程教学必须加强勤劳意识教育     

余之意 《江西教育学院学报》2002,23(6):90-91

在全球经济一体化,在举世闻名的《学会生存》观念引导下,出现教育改革世界范围的同步性;而体育课程改革的目标,正是从强健学生身心出发,促进现代青少年的身心协调发展,重视快乐和勤劳的体验,用“三维”健康观,探索丰富多彩的健康的生活方式,挑战自我,培养学生创造新世界良好体能,以推动高校素质教育。  相似文献   

A Survey of William Faulkner''''s Novels'''' Proposition of Endurance     

潘瑶婷 《阿坝师范高等专科学校学报》2005,(2)

人类的苦忍能力(humanendurance)和终究战胜苦难的思想,是威廉福克纳(WilliamFaulkner)对人类命运的概括。在他看来,人类存在虽然已有千百万年历史,但仍然时刻在为自身的生存殚精竭虑,流血流汗,他作品中的人物都在苦忍(endure)。本文试图通过对苦忍命题具体表现形式的分析探讨该命题的意义及其影响力。  相似文献   

马步站桩对下肢力量影响实验的分析     

王立利 《宜春学院学报》2011,33(8)

主要采用实验法、文献资料法和数理统计法,就马步站桩练习对下肢力量发展的影响进行了实验,通过测得受试者实验前后的马步站桩的时间和纵跳摸高的高度两个指标,分析得知马步站桩练习对下肢力量耐力的影响明显,而对下肢爆发力的影响不大。  相似文献   

Ⅴ型胶原蛋白ａ1链基因多态性与有氧耐力表型的关联性     

邓潇潇  杨贤罡  李燕春 《北京体育大学学报》2017,40(2):45-50

摘要：目的：通过分析Ⅴ型胶原蛋白ａ1链（COL5A1）基因多态性与60名中国北方汉族女子专业长跑运动员机能指标的关联性，探寻预测有氧耐力表型的分子标记。方法：采用联合测试法测得无氧阈和最大摄氧量相关指标，肺功仪测得肺功相关指标。用PCR-RFLP分析COL5A1基因的rs13946、rs12722多态性。结果：1）rs12722位点：不同基因型运动员之间无氧阈摄氧量、无氧阈摄氧量相对值有显著性差异（P<0.05），TT型运动员显著大于CC和CT型。2）rs13946位点：该位点与有氧耐力表型以及肺功之间无关联（P<0.05）。3）rs13946-rs12722单体型：携带TC单体型运动员的无氧阈摄氧量和无氧阈摄氧量相对值指标均显著高于非TC单体型运动员（P<0.025）。结论：1）COL5A1 rs12722 TT基因型可作为预测中国北方汉族女子长跑运动员无氧阈强度下机体氧耗量的分子遗传学标记。2）TC单体型可作为预测北方汉族女子长跑运动员无氧阈摄氧量及其相对值指标的分子遗传学标记。  相似文献   

对青少年越野滑雪运动员力量和耐力训练的思考     

董平  范静 《冰雪运动》2010,32(2):46-49

我国运动员在越野滑雪这一体能主导类项目中不具优势,其耐力素质较差,难于在比赛后程及上坡阶段保持充沛的体力;力量素质较差常导致动作技术变形进而影响运动成绩;且缺乏连续参加大型比赛的素质。我国越野滑雪运动员的力量和耐力素质亟待加强,而其训练敏感期在青少年时期,故应充分考虑青少年越野滑雪运动员的生理特点、运动技能形成的年龄规律、身体素质发展的敏感期等因素,制定科学合理的长期训练计划、强化力量和耐力素质训练,以期为我国越野滑雪的发展献计献策。  相似文献