普通男大学生有氧能力监测指标研究

本文目的旨在筛选我国大学生体质有氧能力监测指标,为其健康测试指标体系提供理论依据。方法:将实验对象分为建模组和评估组,以VO2max和AT作为效标,将建模组1000m跑、12min跑、20m往返跑、台阶试验指数的测试结果与效标进行相关性分析,筛选指标;而后以筛选的指标为自变量,VO2max为因变量,建立预测VO2max的回归模型进行线性回归分析,再通过评估组对VO2max预测模型进行实效性评估,以确定指标的优良性。结果:(1)12min跑和20m往返跑不仅与VO2max之间呈高度相关性,而且与VT之间也表现出较高的相关性;1000m跑与VO2max和VT之间相关性很低;台阶试验指数与VO2max和VT之间均无相关性。(2)以12min跑、20m往返跑建立预测VO2max的回归模型拟合优度均较高,预测效果通过相关性检验和配对t检验显示实效性均较好。结论:(1)12min跑不仅是一项能有效评价大学生有氧能力的指标,而且还是一种科学的有氧健身方式;(2)20m往返跑也可以有效地反映大学生有氧能力水平;(3)1000m跑和台阶试验指数不适合作为评定大学生有氧能力的指标。     

当代儿童幻想小说中的“穿越”故事

“穿越”是当代儿童幻想小说中的一大主题,不同类型的儿童幻想小说中都含有穿越空间或时间的故事。这些“穿越”故事往往包含“门”、现实世界与幻想世界这三个要素,它们在故事中有着不同的表现与作用。而想象力与游戏精神则是“穿越”故事蕴含的两大本质内涵。     

Respiratory responses and rating of perceived exertion of severely obese adolescents during continuous and intermittent graded walking protocols: Application to cardiorespiratory field tests

ABSTRACT

During 20 m shuttle tests, obese adolescents may have difficulty achieving maximum cardiorespiratory performance due to the presence of braking-relaunch phases (BRP). Nineteen obese adolescents aged 15.2 ± 1.5 years (body mass index [BMI] = 39.7 ± 5.9 kg.m^?2) performed three graded walking exercises on a 50 m track at speeds between 3 and 6 km/h: a continuous-straight-line protocol (C), a continuous protocol that required turning back every 30 sec (C-BRP) and an intermittent protocol that consisted of successively walking then resting for 15 sec (15–15). Oxygen uptake (VO₂), aerobic cost of walking (Cw), ventilation (VE) and rating of perceived exertion (RPE) were measured at each stage during the protocols. During C-BRP, the responses were not significantly higher compared with C (p > 0.30). During 15–15, the VO₂, Cw and VE were ~ 15 to 25% lower than during C beginning at 4 km/h (p < 0.05). In obese adolescents, the respiratory impact of sudden directional changes during the 20 m shuttle-type test appeared to be minor at walking speeds. During the 15–15 test, the intensity increases more progressively, and this design may encourage obese adolescents to walk further than during a continuous test.     

碳水化合物对高强度折返运动能力的影响

运动对人体代谢的需要是代表一种营养上的挑战。营养能提供体内能量的再补充、生长、修复和水份的补充。运动期间能量代谢，碳水化合物扮演着重要的角色。虽然许多研究报告表明运动中补充碳水化合物可提高持续亚极限运动的耐力，但有些项目如足球、篮球等运动移位的方式，包括了高低速度折返跑和冲刺运动。本文研究的目的是了解碳水化合物对折返能力的影响     

20-MST监测心肺功能变化的有效性及敏感性研究

目的:探讨20-MST监测普通大学生心肺功能变化的有效性及对运动训练的敏感性。方法:以32名男性大学生(实验组、对照组各16名)为研究对象,对实验组学生进行8周的有氧耐力训练干预,在实验前后分别测定VO2max、20-MST、库博12min跑、台阶试验四项指标,并对检测结果进行分析比较。结果:20-MST在实验前后与VO2max、12min跑成绩高度相关,与台阶指数低度相关;实验后,各指标均有显著增长,20-MST的增量最明显。结论:20-MST是一种间接评价心肺功能、判断训练效果的有效方法,它对评价运动训练引起心肺功能适应性变化的敏感性高于VO2max。     

Estimation of aerobic fitness from PACER performance with and without body mass index

Purpose: To develop models to estimate aerobic fitness (VO₂max) from PACER performance in 10- to 18-year-old youth, with and without body mass index (BMI) as a predictor. Method: Youth (N = 280) completed the PACER and a maximal treadmill test to assess VO₂max. Validation and cross-validation groups were randomly formed to develop and examine accuracy of models. Participants were classified into FitnessGram® Healthy Fitness Zone categories based on measured and estimated VO₂max and criterion-referenced validity was evaluated. Results: Multiple correlations between measured and estimated VO₂max ranged from .70 to .73, with standard errors of estimate between 6.43 and 6.68 mL·kg^?1·min^?1. Accuracy with and without BMI was nearly identical. Overall, criterion-referenced validity evidence was moderate. Conclusion: Moderately accurate and feasible models were developed. Minimal improvement in accuracy was noted when BMI was added as a predictor. The model with PACER and age as predictors has a high level of utility for youth fitness testing.     

规约下的性灵绽放——小说《我的兄弟叫顺溜》中“顺溜”人物形象解析

来自乡野、喝兽奶长大的顺溜,在新四军的阵营中、在炮火的洗礼下逐渐向一个成熟的军人走近,军纪和命令既有对他行为与情感的规约,也有让他挥洒性灵的时刻。部队的生活经历既让他加强了对军纪的认识,也加重了他的情感砝码。顺溜始终穿梭游走在规约和性灵织就的网格中,在左冲右突后,最终从规约和性灵的交融穿梭中挣脱出来,让性灵之花得以绽放。尽管他的军人生命时段只能是短暂的,但其艺术形象却是不朽的。小说作者留给我们的这一深沉思索是改编后的电视剧所匮乏的。     

宽带式长冲程双井抽油机方案设计

针对普通链条式抽油机能耗大、故障率高等问题,提出了宽带式长冲程双井抽油机设计方案。该抽油机运用了双井抽油原理,采用了双链条传动机构。往返架利用导轨导向,用滚筒替代换向滑块。分析认为,宽带式长冲程双井抽油机具有效率高、冲程长、可靠性高、维护方便等一系列特点和优点,具有较高的推广应用价值。     

从"shuttle bus"联想到"_车"的英译

车是现代社会和生活不可或缺的东西.随着社会的发展,科技的进步,车的花样也层出不穷,车名也日新月异.随着对外商务和文化交流日益频繁,对各种车的翻译成了涉外活动中尤其是英语应用者经常接触的内容.本文从剑桥商务英语中出现的shuttle bus英译开始,对车进行粗略的分门别类后并对各种车的翻译作简单的归纳,便于学习者日常记忆和应用.     

Repeated sprint ability in young basketball players: one vs. two changes of direction (Part 1)

The present study aimed to compare the changes of direction on repeated sprint ability (RSA) vs. intensive repeated sprint ability (IRSA) protocols in basketball. Eighteen young male basketball players performed on RSA [10 × 30-m (15 + 15-m, one change of direction)] and IRSA [10 × 30-m (10 + 10 + 10-m, two changes of direction)]. A correlation matrix between RSA, IRSA, “squat jump (SJ)–countermovement jump (CMJ)”, footstep analysis and total distance in Yo-Yo intermittent recovery level 1 was performed. The best time, worst time, total time and the number of footsteps were significantly smaller in the RSA test compared to IRSA test (P < 0.001), even though they were significantly correlated with each other (r > 0.80, P < 0.05). Blood lactate level and fatigue index did not show any difference between tests. The sensibility of the two tests assessed by the Bland–Altman analysis revealed a small bias (<1.5%) for almost all variables. Moreover, almost all time variables of the two tests were significantly correlated with the SJ (r > 0.478, P < 0.05), CMJ (r > 0.515, P < 0.05) and Yo-Yo (r > 0.489, P < 0.05) performances. The IRSA provided a reliable method for assessing specific sprint ability (with 10-m legs for IRSA ~2.3 s vs. 15 m for RSA ~3 s) with a closer link to basketball game’s actions (~2 s). Besides, IRSA could be an appropriate choice for assessing both RSA and changes of direction capacities in basketball players.