共查询到20条相似文献，搜索用时 234 毫秒
1.
运动训练对高脂膳食大鼠主动脉M_2受体的影响 总被引：4，自引：0，他引：4
目的 探讨运动训练对高脂膳食大鼠主动脉M2受体表征的影响.方法 通过建立动物模型,采用跑台训练方式,运用免疫组织化学方法,研究大鼠主动脉M2受体的分布以及运动训练对高脂膳食大鼠主动脉M2受体表达的影响.结果 与安静对照组比较,有氧运动组和高脂膳食加有氧运动组主动脉M2受体表达的平均光密度值(MOD)显著增加;大强度运动组和高脂膳食组均减少,但高脂膳食组差异较显著.结论 大鼠主动脉上有M2受体分布;大强度运动可使高脂膳食大鼠主动脉M2受体的表达减少,但高脂膳食对其影响较为显著;有氧运动显著增加正常大鼠和高脂膳食大鼠主动脉M2受体的表达.因此认为,有氧运动可通过迷走神经有效预防和改善动脉粥样硬化(AS)的发生和发展. 相似文献
2.
3.
目的:构建围青春期体质指数和体脂百分比间最佳曲线模型;探索围青春期体质指数和体脂百分比在增龄过程中的消长规律.方法:以2011年1-12月体质检测中心1 878名(男:940名;女:938名)8～16岁中、小学生为研究对象,测试其身高、体重、体脂含量、体脂百分比及去脂体重,计算其BMI.对其BMI和体脂百分比进行曲线拟合,并根据AIC值和R确定BMI对体脂百分比的最佳模型;根据不同年龄段BMI和体脂百分比年度增量值探讨BMI和体脂百分比增龄消长规律.结果:1)一至六次曲线中仅直线、二次曲线及三次曲线的AIC值和R有显著性差异,分别为872.547、0.807;867.597、0.812;863.937、0.815.2)围青春期女生体脂百分比增量峰值分别出现于8～9岁和13～14岁,谷值出现于9～10岁;BMI增量峰值出现于10～11岁,14～15岁;谷值出现于12～13岁.男生体脂百分比增量峰值出现于9～10岁,11～12岁,14～15岁;谷值出现于10～11岁,13～14岁;BMI增量峰值出现于9～10岁,12～13岁,14～15岁,谷值出现于10～11岁,15～16岁.结论:1)三次曲线被证实为拟合围青春期体质指数和体脂百分比协同变化关系的最优模型;2)受性激素非匀速分泌影响,男孩体脂百分比与BMI增龄特点类似,呈现“三峰两谷”特点,女孩体脂百分比与BMI增龄均呈现“两谷一峰”特点. 相似文献
4.
扭转秋千测定人体转动惯量的关键在于是否具有谐振系统的等时性。受惠更斯设计不等长摆时钟的启发,经过数学的推演和力学的论证,提出可变臂长弹性扭转秋千的设计构想,并对等时性成立的最适扭转角作了详细的估算 相似文献
5.
6.
中国城镇居民身体脂肪分布及增龄变化规律的研究 总被引：1，自引：0，他引：1
随着生长发育和体力活动等的进行,人体的身体成分会发生不同程度的改变,其中,身体脂肪含量的分布和变化规律的研究受到人们的关注.选取济南、广州、成都和西安4个城市的3～69岁城镇居民为研究对象,采用DEXA对受试对象的全身及各部位身体成分进行测量与分析.研究结果表明,我国城镇居民的体脂含量随年龄的增长而增大,并呈现出明显的阶段性,其中,男性分为3～6岁、7～29岁和30～69岁3个阶段;女性分为3～6岁、7～12岁、13～39岁和40～69岁4个阶段.进入成年后,我国城镇居民体重还在继续增长,但绝大部分是脂肪,男性约在88%,女性约在95%,而肌肉含量和骨矿物质保持平稳并略有下降.我国城镇居民身体脂肪的分布具有明显的增龄性规律,男性增龄性变化主要是向心性聚集,随年龄增长全身脂肪的50%～60%含量聚集在身体躯干部位,四肢的体脂率随年龄增长呈下降趋势;女性的脂肪随年龄的增长则主要向躯干和大腿两个部位聚集. 相似文献
7.
目的:探讨M2受体的细胞表征及其运动与心脏、血管M2受体的基础与应用前景.方法:采用文献回顾与前瞻性分析及逻辑推理相结合的方法,跟踪M2受体表征研究进展及其运动与心脏、血管M2受体表征在体育科学领域中的应用.结果与结论:M2受体在心肌、血管平滑肌等细胞上广泛分布,具有重要的生物学功能.不同运动强度和心肌细胞M2受体表征、运动后心率恢复与M2受体基因多态性、心脏运动康复与M2受体表征等的关系密切.积极开展M2受体基因变异与运动前预测心源性死亡风险,运动性心律失常与M2受体表征,运动性心肌损伤引起的心功能紊乱与M2受体表征,基于M2受体靶点的心脏、血管运动康复及其中药有效成份筛选等方面的研究,具有重要的基础研究价值和应用前景.对有效筛选心脏、血管运动康复方案和与M2受体相关药物有效成份具有重大意义. 相似文献
8.
体脂百分比是影响滑冰运动员成绩的一个重要因素。世界优秀速滑选手体脂百分比大约保持在11％左右,我国选手明显高出此范畴。这种情况可能与我国选手的饮食结构、训练手段有关。体脂高,瘦体质量小会导致成绩差是公认的事实。因此采取有效措施扭转这种局面是十分必要的。 相似文献
9.
根据BMI和体脂百分比标准判别成人肥胖度效力的评估性研究 总被引：3，自引：0，他引：3
用WHO推荐的BMI标准和日本体脂百分比标准,对5 020名18～22岁成年学生的肥胖度进行交互判别的结果显示,对体脂正常者与体重偏轻者的判别结果一致性程度较高,其差异不超过10%,但被F%标准判别为轻、中、重度肥胖者的比例大于用BMI标准判别为超重和肥胖者的比例.如按F%标准衡量,在男女BMI正常者中约10%～20%的人属于超重或肥胖者.BMI的第95%位数相当于BMI超重标准,F%的第85%位数相当于F%的男子轻度肥胖与女子中度肥胖标准. 相似文献
10.
目的:旨在研究重大比赛前最佳状态时游泳运动员的身体成分,按不同性别、不同距离、不同运动等级、不同年龄段进行分类比较.方法:以浙江游泳队45名运动员为研究对象,测试时间为早上7点,空腹,采用韩国INBODY3.2型身体成分分析仪进行分析.研究结果:游泳运动员,男子体脂率应保持在9%左右,女子体脂率应保持在15%左右较为理想;短距离游泳运动员体脂率明显低于中长距离运动员;瘦体重明显高于中长距离运动员;男子游泳运动员身体成分比例较合理的出现在19～21岁这个年龄段,女子出现在16～18岁这个年龄段;游泳运动员体脂率高低与运动等级的相关性不大. 相似文献
11.
我国蹦床运动员起跳网上转体研究报告 总被引：3，自引：0，他引：3
主要采用摄像法和影像解析法对我国蹦床运动员起跳网上转体问题进行研究。研究结果表明:起跳网上转体目前是我国蹦床运动员普遍存在的技术错误之一。它不但影响腾起高度及动作姿态,还易导致身体横向水平位移。当完成翻转周数、转体度数较少的空翻转体动作时应采用非惯性转体技术;当完成翻转周数、转体度数较多的空翻转体动作时,在保证充分压网与蹬伸的前提下,身体离网瞬间即可开始转体。 相似文献
12.
This paper introduces the first stage of a new model-based approach to three-dimensional (3D) human movement tracking. A ‘generate-and-test’
matching procedure was adopted by matching rendered images of a 3D computer graphics model of the human body to target images
of rigid body motion. The set of pixels to be compared were just those corresponding to the model of the body in the rendered
images. The matching criterion to optimize model position and orientation was based on the minimisation of the RGB (red-green-blue)
colour difference between generated model images and associated target images. The method was able to track synthetic image
sequences of a half twisting somersault accurately with root-mean-square (rms) errors of less than 5 mm and 0.3∘ for position
and orientation estimates respectively. The suitability of the proposed approach for rigid body motion tracking was supported
by additional tracking experiments on video image sequences of ‘wooden cross’ trajectories. Comparisons of tracked estimates
against manual digitizing estimates returned relatively small rms difference values on both side somersault and twisting somersault
movements. The proposed approach has the potential to track video images of a human torso using a rigid body model and hence
to track articulated movements by successively adding segments to the model in a hierarchical manner. 相似文献
13.
Vivian H. Heyward Sandra M. Johannes-Ellis Jacki F. Romer 《Research quarterly for exercise and sport》2013,84(2):154-159
The purpose of this study was to examine gender differences in upper and lower body strength as a function of lean body weight and the distribution of muscle and subcutaneous fat in the upper and lower limbs. The subjects were 103 physically active men (n = 48) and women (n = 55). The peak torques produced during shoulder flexion (SF) and knee extension (KE) were used as measures of upper body and lower body strength, respectively. Flexed arm girth, thigh girth, triceps skinfold, and thigh skinfold were used to estimate the distribution of muscle and subcutaneous fat in the limbs. Results of the MANOVA revealed that the overall strength of men was significantly greater than that of women. Results of MANCOVA indicated that the SF and KE strength of women and men did not differ significantly when differences in lean body weight, arm girth, thigh girth, triceps skinfold and thigh skinfold were statistically controlled. High levels of SF and KE strength were associated with a high lean body weight and a large arm girth. Results of the multiple regression analysis indicated that for men a substantial portion of the variance in both SF and KE strength was explained by lean body weight alone; whereas strength variations in women were explained more adequately by including limb variables along with lean body weight. Within the limitations of this study, it was concluded that gender differences in upper and lower body strength are a function of differences in lean body weight and the distribution of muscle and subcutaneous fat in the body segments. Upper body strength is relatively more important than lower body strength in characterizing the gender difference in strength. 相似文献
14.
皮褶厚度法间接测定中国人身体脂肪含量公式的初步建立 总被引：6，自引：1，他引：5
以不同年龄、不同性别的一般人群为实验对象,分别采用皮褶法和水下称重法测定身体脂肪含量。结果发现,采用国外皮褶公式求得的体脂含量与经典水下称重法相比有显著性差异。实验表明,测定我国人群的脂肪含量不宜直接套用国外皮褶公式。实验以水下称重法为标准,采用逐步回归初步建立了适合我国人的皮褶厚度推算身体脂肪含量的回归方程 相似文献
15.
Stephen Ball Celsi Cowan John Thyfault Tom LaFontaine 《Measurement in physical education and exercise science》2014,18(3):198-208
Skinfold prediction equations recommended by the American College of Sports Medicine underestimate body fat percentage. The purpose of this research was to validate an alternative equation for men created from dual energy x-ray absorptiometry. Two hundred ninety-seven males, aged 18–65, completed a skinfold assessment and dual energy x-ray absorptiometry scan to determine percent of body fat. Three American College of Sports Medicine equations (JP7, JP3a, and JP3b) and the new dual energy x-ray absorptiometry criterion equation were used to predict percent of body fat. Mean age was 32.4 ± 14.0 years and mean BMI was 25.6 ± 3.3 kg/m2. The mean dual energy x-ray absorptiometry percent of body fat was 18.0 ± 5.9. The mean percent of body fat for Dual Energy X-Ray Aborptiometry (DC), JP7, JP3a, and JP3b were 19.1 ± 6.3, 16.1 ± 7.4, 14.8 ± 6.8, 15.6 ± 6.7, respectively. The standard error of the estimate of DC was low (2.72%) and was highly correlated (R2 = 0.87) with dual energy x-ray absorptiometry. The DC equation more accurately predicted percent of body fat across a general population of men than the recommended American College of Sports Medicine equations. 相似文献
16.
文章通过对山西大学、山西财经大学、太原理工大学、中北大学等高校2010年度校运动会上,各个项目前八名男子运动员与在校二级高水平运动员体成分进行比较,旨在找出某些规律性特征,从而为运动员科学选材、有效控制体重提供一定的客观依据。 相似文献
17.
18.
Timothy J. Suchomel George K. Beckham Glenn A. Wright 《Sports biomechanics / International Society of Biomechanics in Sports》2014,13(1):87-95
This study examined the impact of load on lower body performance variables during the hang power clean. Fourteen men performed the hang power clean at loads of 30%, 45%, 65%, and 80% 1RM. Peak force, velocity, power, force at peak power, velocity at peak power, and rate of force development were compared at each load. The greatest peak force occurred at 80% 1RM. Peak force at 30% 1RM was statistically lower than peak force at 45% (p = 0.022), 65% (p = 0.010), and 80% 1RM (p = 0.018). Force at peak power at 65% and 80% 1RM was statistically greater than force at peak power at 30% (p < 0.01) and 45% 1RM (p < 0.01). The greatest rate of force development occurred at 30% 1RM, but was not statistically different from the rate of force development at 45%, 65%, and 80% 1RM. The rate of force development at 65% 1RM was statistically greater than the rate of force development at 80% 1RM (p = 0.035). No other statistical differences existed in any variable existed. Changes in load affected the peak force, force at peak power, and rate of force development, but not the peak velocity, power, or velocity at peak power. 相似文献
19.
Massimiliano Ditroilo Roberta Forte David McKeown Colin Boreham Giuseppe De Vito 《Journal of sports sciences》2013,31(15):1675-1682
Abstract Despite its widespread use in performance assessment, the reliability of vertical jump in an ageing population has not been addressed properly. The aim of the present study was to assess intra- and inter-day reliability of countermovement jump in healthy middle-aged (55–65 years) and older (66–75 years) men and women. Eighty-two participants were recruited and asked to perform countermovement jumps on two different occasions interspersed by 4 weeks. The middle-aged groups exhibited excellent absolute reliability for flight height, jump height, peak force, peak power, peak force/body mass, and peak power/body mass, with coefficients of variation ranging from 2.9% to 7.2% in men and from 3.6% to 6.9% in women and moderate-to-high intraclass correlations (0.75 to 0.97 in men; 0.77 to 0.95 in women). The older groups displayed good coefficients of variation (4.2% to 10.8% in men and 3.4% to 9.5% in women), but the intraclass correlations were low-to-high (0.43 to 0.84 in men; 0.42 to 0.93 in women). Overall, intra-session reliability was higher than inter-session reliability. Peak power was by far the most consistent variable, whereas flight and jump height had the most marked variability. The minimum detectable change varied from 10.5% to 33%, depending on the variable examined, suggesting important implications for intervention studies. 相似文献
20.
Oxygen uptake (VO2) during treadmill exercise is directly related to the speed and grade, as well as the participant's body weight. To determine whether body composition also affects VO2 (ml.kg-1.min-1) during exercise, we studied 14 male body builders (M weight = 99 kg, SD = 7; M height = 180 cm, SD = 8; M body fat = 8%, SD = 3; M fat free mass = 91 kg, SD = 7) and 14 weight-matched men (M weight = 99 kg, SD = 9; M height = 179 cm, SD = 5; M body fat = 24%, SD = 5; M fat free mass = 73 kg, SD = 9). Percentage of body fat, t(13) = 8.185, p < .0001, and fat free mass, t(13) = 5.723, p < .0001, were significantly different between groups. VO2 was measured by respiratory gas analysis at rest and during three different submaximal workrates while walking on the treadmill without using the handrails for support. VO2 was significantly greater for the lean, highly muscular men at rest: 5.6 +/- 1 vs. 4.0 +/- 1 ml.kg-1.min-1, F(1, 26) = 21.185, p < .001; Stage 1: 1.7 mph/10%, 18.5 +/- 2 vs. 16.1 +/- 2 ml.kg-1.min-1, F(1, 26) = 6.002, p < .05; Stage 2: 2.5 mph/12%, 26.6 +/- 3 vs. 23.1 +/- 2 ml.kg-1.min-1, F(1, 26) = 7.991, p < .01; and Stage 3:3.4 mph/14%, 39.3 +/- 5 vs. 33.5 +/- 5 ml.kg-1.min-1, F(1, 26) = 7.682, p < .01, body builders versus weight-matched men, respectively. However, net VO2 (i.e., exercise VO2 - rest VO2) was not significantly different between the two groups at any of the matched exercise stages. The findings from this study indicate that VO2 during weight-bearing exercise performed at the same submaximal workrate is higher for male body builders compared to that measured in weight-matched men and that which is predicted by standard equations. These observed differences in exercise VO2 appear to be due to the higher resting VO2 in highly muscular participants. 相似文献