锻炼也会上瘾

　　2015复习正是强化复习阶段，在考研英语中占了40分，所以考研英语阅读是英语科目中重要的一项。名师老师曾建议过考研生需要坚持每天泛读10-15分钟的英文原刊。强烈推荐了杂志《经济学人》.杂志中的文章也是考研英语的主要材料来源.希望考研考生认真阅读，快速提高考研英语阅读水平。 　　Exercise and addiction 　　锻炼也会上瘾 　　Fun run 　　奔跑的奥秘 　　People, it seems, have evolved to be addicted toexercise 　　人类似乎在进化过程中对锻炼上瘾了 　　AS THE legions of gym bunnies and jogging enthusiasts who race out into the spring sunshineevery year clearly demonstrate, running can be fun. 　　那一大批在春日和煦的阳光中奔跑着的健身爱好者无不向我们展示着奔跑的乐趣。 　　More specifically, running triggers the release of brain chemicals called endocannabinoidsthat create a potent feeling of pleasure. 　　更确切地讲，在奔跑时人体内有一种化学物质被释放，从而使人产生一种强烈的愉悦感。 　　As their name suggests, these endocannabinoids work in the same way as the activeingredient of marijuana. 　　正如其名字的含义一般，这些endocannabinoids有着跟大麻中的有效成分一样的效果。 　　From an evolutionary standpoint this surge of endocannabinoids, and the runner s high itcreates, make sense. 　　从进化论的观点来看，人体内endocannabinoids水平的上升及由此而生的赛跑者的亢奋对人类的发展是有意义的。 　　For ancient humans, remaining fit enough to run after game and away from predators andenemies was vital for survival. 　　那些远古时代的人类，为了能够顺利追捕到猎物并从其他猎食者的追击中逃脱，必须将身体状态始终维持在一个良好的水平。 　　Yet whether other mammals are also driven to exercise by endocannabinoids has remained amystery. 　　既然人类如此，那么其他哺乳动物是否也会在endocannabinoids的内在驱动下而进行锻炼呢? 　　Now a study led by David Raichlen of the University of Arizona has revealed that the runner shigh does exist in other species, but not in all. 　　这仍是个未解之谜。现在一项由Arizona大学的David Raichlen博士领衔的研究已经在其他哺乳动物体内-并非全部都有-发现了endocannabinoids的存在。 　　You expect me to what?! 　　你猜我在干什么?! 　　Dr Raichlen hypothesised that endocannabinoid-driven exercise highs would be found in thosemammals that gain an evolutionary benefit from being fast on their feet: antelopes, horsesand wolves, for example. 　　Raichlen先提出了一个假设：像羚羊，马和狼这样一些因拥有飞毛腿而在进化过程中受益的哺乳动物中也存在着锻炼产生的兴奋现象; 　　However, he also thought that they would not be present in those which are known for beingquick and agile, but not for running, like ferrets. 　　而那些以灵动著称，却非凭奔跑文明的动物，如雪貂，则不会出现此现象。 　　To test these ideas, he and a team of colleagues devised an experiment that monitored theendocannabinoid levels of different species after they had been walking or running on atreadmill. 　　为了检验这些猜想，Raichlen和由其同事所组成的团队设计了一个实验-对在跑步机上行走，奔跑过后的动物体内的endocannabinoids水平进行监控。 　　The experimental animals in question were ten people, eight dogs and eight ferrets. 　　被考虑用来进行实验的动物有以下三种：十个人，八条狗和八只雪貂。 　　Dr Raichlen had them run or walk on the treadmill for 30 minutes. 　　Raichlen博士先让他们在跑步机上行走或奔跑30分钟。 　　Since running and walking speeds differ from species to species, the speed at which thetreadmill moved was varied so that it raised the heart rates of the different participants tothe same level. 　　由于不同的动物速度不一，所以跑步机的传送带速度设置是以使不同动物的心率达到同一水平为依据。 　　Running speeds were thus set at 2.5 metres a second for people, 1.83 for dogs and 0.84 forferrets. 　　这样设置的结果便为：奔跑速度为人类2.5米/秒，狗1.83米/秒，雪貂0.84米/秒; 　　Walking speeds were set at 1.25 metres a second for people and 1.1 for dogs. 　　行走速度为人类1.25米/秒，狗1.1米/秒。 　　The ferrets proved too easily distracted to walk consistently on the treadmills and were thusleft to sit quietly in their cages for this part of the study. 　　雪貂由于太易分心，没办法让它持续在跑步机上行走，所以在进行该部分实验时它们被留在了笼中静静地坐着。 　　Each participating animal ran for one session and walked for one other, and did so onseparate days, to avoid exhaustion. 　　每只动物会跑一段走一段，为了避免动物们出现筋疲力尽的情况，实验是分成几天进行的。 　　Before and after each session, blood was drawn from each and the endocannabinoid levels init were measured. 　　在实验前和试验后，动物们都会被抽血以检验其中的endocannabinoid水平。 　　The researchers report in the Journal of Experimental Biology that, after 30 minutes ofwalking, participants endocannabinoid levels did not rise. 　　研究人员在《生物学实验》杂志中提到，在经过30分钟的行走之后，参加实验的动物的endocannabinoid水平并没上升。 　　After running, however, the average human s endocannabinoid levels rose from 2.4picomoles per millilitre to 6.1. 　　然而在奔跑过后情况则有所不同：那10个人的平均endocannabinoid水平从2.4 pmol/ml上升到了6.1pmol/ml。 　　Dogs showed a similar trend, with levels rising from 2.4 pmol/ml to 8.0. 　　狗的变化趋势与人类似---由2.4 pmol/ml升至8.0 pmol/ml。 　　Ferrets were different. Although they did show an increase, from 3.0 to 3.9 pmol/ml, this wasnot a statistically significant rise. 　　唯独雪貂例外。他们的endocannabinoid水平虽亦有所上升-3.0 至 3.9 pmol/ml，但仍处于统计学上可不被纳入考虑的范围内。 　　These findings suggest that dogs experience a runner s high but ferrets do not. 　　这些发现表明狗中同样存在着赛跑者的亢奋现象，而雪貂则没有。 　　Dr Raichlen argues that it makes sense for ferrets not to have systems that rewardcardiovascular activity, since such exercise consumes a lot of energy, may cause injury, andis not crucial to the stealthy hunting technique of sneaking down burrows and killing rabbitsin their sleep. 　　看来雪貂体内并不存在对心血管活动进行阳性强化刺激的系统，Raichlen博士认为这对雪貂的发展同样是有意义的，要知道太剧烈的运动会消耗掉过多的能量， 甚至引发受伤，且这并非是雪貂捕猎技术中的关键-它们一般只需偷偷溜进兔子窝并在兔子们熟睡时将其杀死即可。 　　What is not clear is whether the endocannabinoid reward is an ancient mechanism that hasbeen lost on branches of the mammalian tree that do not need it, or is something thatevolves quickly in species which become active. 　　仍有待考证的是，究竟这种endocannabinoid刺激机制是从远古时代起即为哺乳类动物所拥有，还是从某些活跃的个别物种中进化出来的? 　　Given that humanity s arboreal simian ancestors would presumably have had little need torun, it is probably the latter. 　　鉴于人类的祖先类人猿是树栖动物，据推测它们很少有奔跑的需要，因此正确结论很可能是后者。 　　But to be sure Dr Raichlen will need to put animals far less co-operative than ferrets on thetreadmill. 　　但若要确认此假设，Raichlen博士需将更多如雪貂般不太合作的动物哄上跑步机。 　　词语解释 　　1.evolve to 进化 　　That s the magic that can make a small ideaevolve to be a revolutionary one. 　　这是让小点子演变成具有革命性创意的魔法所在。 　　Over time, the computer industry will evolve toinclude all aspects of our lives. 　　假以时日，电脑业的发展将会涵盖我们所有的生活层面。 　　2.enough to 足以 　　That s not enough to trigger renewed recession. 　　这个问题不足以导致美国经济重新陷入衰退。 　　It tells you enough to get started right away. 　　它告诉你的东西足够让你立刻开始使用。 　　3.benefit from 获益;受益 　　The economy now would benefit from some real engineering. 　　现在一些真正的工程才会令该国经济受益。 　　Humans are not the only species to benefit from foxp2. 　　人类并不是唯一受益于foxp2基因的物种。 　　4.differ from 不同于 　　But future purchases will differ from previous ones. 　　但未来的债券购买计划会和以前的有所不同。 　　How and why does this differ from the advice from the who? 　　这项研究如何以及为什么与世卫组织的建议不同?