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新视野大学英语 读写教程第三册 unit2-b

2011-07-29    来源:网络    【      美国外教 在线口语培训

Does Exercise Have Unexpected Benefits?

Just as exercise strengthens the heart and lungs, bones and muscles, it may also power up the brain.

A succession of scientific studies of animals implies that physical activity has a positive effect on mentalfunctioning.

"It's clear that the brain benefits from exercise," says brain scientist William Greenough of theUniversity of Illinois at Urbana-Champaign. His studies with rats have demonstrated two primaryeffects of activity: vigorous physical exercise provides the brain with more fuel, and skill-based exerciseincreases the formation of connections in the brain, which, according to the proposals of some scientists,may make the brain better able to process information.

In one experiment, laboratory rats were separated into three groups. One group was exercised byrunning inside an automatic wheel, a second group improved their skills in a complicated obstaclecourse, and a third group was inactive.

"The animals that learned to go through the obstacle course exhibited a greater number of brainconnections than the animals in the exercised or inactive groups," Greenough said. "In contrast, theanimals that exercised inside the automatic wheel possessed a greater density of blood vessels in thebrain than did either of the other two groups of animals."Learning a new dance step may boost the brain in the same way that learning a language can, hesays. And if the dance is a good physical exercise as well, the benefits multiply. Young brains may beespecially able to boost brain power through exercise, suggested another of Greenough's experimentsthat showed the most significant changes in the brain occurred among rats that had been exercisedwhen very young. And while animals aren't people, he says it is logical to make the inference that aneffect found in rats may also apply to humans.

Human studies have focused primarily on older adults and suggest that regular exercise can improvethe speed with which the brain processes information. Measurements made by Arthur Kramer at theUniversity of Illinois demonstrated that inactive adults, aged 63 to 82, could hit buttons faster inresponse to a tone after they went through a 10-week water exercise course. A corresponding controlgroup that didn't exercise showed no improvement.

This boost in reaction time after exercise training may occur because declines associated with gettingold could actually stem from declines in physical condition. Some scientists speculate the reduction inmental function often attributed to getting old may really be a penalty of neglecting to stay physicallyactive, in addition to related factors such as medicines and poor diet.

"In older people, an exercise program appears important for brain maintenance," says Daniel M.

Landers, professor of exercise science at Arizona State University, who recently published an articlereviewing the scientific literature on activity's effect on the brain.

Numerous studies show that children who engage in regular physical activity do better in school thantheir inactive classmates. But until recently, the academic edge gained by participating in sports wasthought to come from the increased self-confidence, the better mood, and the ability to concentratethat comes from burning off steam in exercise. Now, however, some scientists have revised their way ofthinking, and point to possible physical connections.

Pierce J. Howard, another expert, says new research indicates that physical exercise increases theamount of certain brain chemicals that stimulate growth of nerve cells. Consequently, the brains ofpeople who exercise may be better equipped to tackle mental challenges.

Inactivity may also have negative effects on mind and body alike. "Scientists recognize that mind isbody, and body is mind," comments Howard. The most beneficial forms of exercise, he says, engageboth. 

New Words

succession n. 1.一连串的事物,一系列 2.连续,接续 3.继任(权),继承(权)

imply vt. 暗示,暗指

rat n. 鼠,大老鼠

primary a. 1.首要的,基本的,主要的 2.最初的,最早的

vigorous a. 强壮的,有力的,精力充沛的

formation n. 1.组成,形成 2.形成物,结构 3.排列,队形

proposal n. 1.建议,计划,方案 2.求婚

laboratory n. 实验室

complicated a. 复杂的,难以理解或解释的

obstacle n. 障碍(物)

exhibit vt. 1.显示,显出 2.陈列,展览 n. 展览品,陈列品

possess vt. 拥有,具有

density n. 密集;密度

multiply v. 1.(使)增加,(使)繁殖 2.乘

boost vt. 改善,提高,增强,推动 n. 增加;帮助;鼓舞

logical a. 合乎逻辑的,条理分明的

inference n. 1.推断的结果,结论 2.推论,推断,推知

primarily ad. 首先,主要地,基本地

measurement n. 1.测量,衡量 2.(量得的)尺寸,大小

corresponding a. 相应的,对应的

stem vi. 源于,由... ...造成 n. (植物、灌木或树木的)茎,干

speculate v. 推测,推断

reduction n. 1.减少,减低,减缩 2.减少,减低,缩小

penalty n. 处罚,惩罚;罚金

neglect vt. 1.忽视,忽略 2.遗忘 n. 疏忽,忽略

maintenance n. 1.维护,保养 2.保持,维持

academic a. 1.学术的,学院的 2.纯理论的,不切实际的

concentrate v. 1.集中,集中精神 2.集中,聚集

revise vt. 1.修正,修改 2.复习,温习

cell n. 细胞

consequently ad. 因此,所以

equip vt. 1.使有准备 2.配备,装备

tackle vt. 1.处理,应付 2.与... ...交涉

alike ad. 一样地,相似地 a. 相同的,相像的

comment v. 评论,发表意见  n. 评论,意见

beneficial a. 有助的,有利的,有益的

Phrases and Expressions

separate… into 将... ...分为

obstacle course 越障训练;(喻)困难重重的事

go through 完成,通过

in contrast 相比之下

apply to 适用于

focus on 集中于

engage (oneself) in 从事,忙于

point to 表明;表示

Proper Names

William Greenough 威廉·格里诺

University of Illinois at Urbana-Champaign 伊利诺伊大学厄巴纳-尚佩恩分校

Arthur Kramer 阿瑟·克雷默

Daniel M. Landers 丹尼尔·M. 兰德斯

Arizona State University 亚利桑那州立大学

Pierce J. Howard 皮尔斯·J. 霍华德



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