好英语网关于健身和锻炼的科学知识
Before you head to the gym, here are seven fascinating insights from science to help motivate you and get more from your exercise.
在你去健身房锻炼之前，可以先了解一下这7项有趣的科学知识，这将有助于你提高健身的积极性，改善健身的效果。
1. Why exercise boosts IQ
1. 健身为什么能提高智商？
Consider this: children who walk to school concentrate better and get better test results; older people who enjoy mild exercise are half as likely to suffer from cognitive impairments.
先来看两个数据：走着上学的儿童注意力更集中，学习成绩也更好；喜欢适当健身的老年人患认知障碍的概率降低一半。
It’s thought that the extra blood supply to the brain promotes the growth of neurons and encourages the release of certain neurotransmitters and growth hormones that are crucial to the brain’s overall health.
专家认为，增加大脑供血可以促进神经元的发育，还能促进人体释放某些对大脑整体健康至关重要的神经传导物质和生长激素。
2. The psychology of workout music
2. 健身音乐的心理学
Which songs get you pumped up for working out? Many of us think exercising to music helps to reduce effort and increase endurance. Why does music have this effect? The answer lies in our brains, not in our muscles, says Tom Stafford in his article on the subject.
锻炼时应该听什么歌？很多人认为，边听音乐边锻炼不仅能省力，还可以增强耐力。音乐为什么能起到这种效果？汤姆·斯坦福德(Tom Stafford)在一篇与此有关的文章中表示， 答案来自我们的大脑，而非肌肉。
The effect seems to be most pronounced for self-paced exercises – running or rowing rather than team sports. The area of the brain that signals the movement of muscles is called the motor cortex. This is where we plan to make movements and it’s especially critical for the timing of actions.
在跑步或划船等个人运动中，音乐的效果似乎最为明显，而团体运动中的效果较差。大脑里发出肌肉运动信号的区域叫做运动皮质。这片区域负责制定运动计划，它对把握运动时机至关重要。
The signal from our music travels down our auditory pathways to the supplementary motor area where, says Stafford, the rhythm of the music may help with the process of timing our actions.
斯塔福德表示，音乐信号会沿着听觉路径传导至辅助运动区，因此音乐节奏可能有助于我们把握运动的时机。
3. Are cramps caused by a lack of salt?
3. 抽筋是因为缺盐导致的吗？
The cause of cramps is something of a mystery. Because they are so difficult to predict, trying to cause one in a lab is not easy, so most studies look at real-life observations.
抽筋的原因至今是个未解之谜。由于很难预测人们何时会抽筋，所以要在实验室里让人抽筋并不容易，因此多数与此有关的研究都需要进行实地观察。
Studies on American footballers show that cramps are more likely to happen in hot weather, which fits with the theory that they are caused by low salt levels, lost through sweat. The problem with this is that athletes in cold climates get cramp too.
对美国橄榄球运动员进行的研究显示，炎热天气更容易抽筋，这似乎印证了出汗缺盐会引发抽筋的理论。但问题在于，这些运动员在寒冷的天气里也会抽筋。
Another study on South African ultra-marathon runners found little difference in sodium levels between athletes that cramped up and those that didn’t. The advice if you are suffering from cramp is to stretch it out. There’s no need to increase levels of sodium.
另一项针对南非超级马拉松运动员开展的研究发现，抽筋的运动员与没有抽筋的运动员体内的钠含量差异很小。专家建议，抽筋时应该尽量伸展，没有必要补充钠元素。
运动音乐的心理学
4. Is stretching before and after exercise necessary?
4. 锻炼前后有必要做点伸展运动吗？
We’re often told that stretching our muscles is the best way to avoid aching limbs the following day or injuries during sport. But is this true?
我们经常听到这样的说法：想要防止运动过后的第二天出现肌肉酸痛或者避免在运动过程中受伤，最好的办法就是做点伸展运动。可事实果真如此吗？
Two studies have both pointed towards an answer: not really. In this article by Claudia Hammond, Rob Herbert from the George Institute in Australia – the author of one of the two reviews – told us that if you enjoy stretching before exercise, you’re fine to carry on, but it probably won't help much. All the evidence points towards little difference in muscle recovery or injury prevention.
有两项研究都指向了同一个答案：事实并非如此。 在克劳迪娅·哈蒙德(Claudia Hammond)的这篇文章中，澳大利亚乔治学院的罗布·赫伯特(Rob Herbert)表示，如果你喜欢在运动前做点伸展运动，那可以继续，但作用可能并不大。所有证据都表明，伸展运动不会对肌肉恢复或损伤预防产生太大作用。
5. Do special running shoes prevent injury?
5. 特制的跑鞋有助于预防损伤吗？
If you’re a keen runner you might have been fitted for personalised running shoes. For this you probably had to run in front of a shop assistant while they told you how much you “pronate” (turn your foot inwards on impact with the floor). But does it matter?
如果你是跑步爱好者，或许应该买一双个性化的跑鞋。所以，你可能需要在店员面前跑几步，他们会告诉你，你“内旋”的程度有多大。但这真的重要吗？
The evidence for the benefits of specialised footwear is so sparse that some consider it a myth. Surprisingly, even the evidence that running on hard surfaces leads to more injuries is weak. But footwear manufacturers will still try to make shoes with claims of better support and injury prevention.
几乎没有什么证据能证明特制跑鞋的作用，所以有人认为这都是虚构的。令人意外的是，甚至没有充分证据证明在坚硬的表面上跑步会造成更大损伤。但跑鞋厂商仍然在努力宣传自己的产品，声称其具备更好的支撑和保护作用。
6. Will we ever run 100m in under nine seconds?
6. 人类百米短跑速度能否突破9秒？
If you're a more determined athlete, you might want to set yourself an ambitious target. But what are the limits of human capability? Ed Yong explored this for us, and unsurprisingly found it a difficult question to answer.
如果你是一个有决心的运动员，可能会给自己制定野心勃勃的目标。但人类的极限究竟是多少？ Ed Yong为我们展开了一番探索，并且惊讶地发现，这其实是一个难以回答的问题。
For most runners, speed is largely determined by how much force they can apply when their foot is on the ground, so there are two options for increasing speed; hit the ground harder or exert the same force for a longer period. Studies show that the calf muscles more than any other determine the amount of force that runners apply to the ground.
对多数跑步爱好者来说，速度很大程度上取决于他们的脚着地时施加的力量，所以可以通过两种方式来加快速度：加大蹬地的力量或者在力量不变的情况下延长蹬地时间。研究表明，当运动员向地面施加压力时，腓肠肌群对跑步产生的影响最大。
People are getting faster but in unpredictable ways. Current estimates show that we’ve yet to reach the ceiling of human speed.
人类的跑步速度越来越快，但方式却不可预知。按照目前的估算，我们尚未达到人类速度的极限。
7. Does exercise really help with depression?
7. 运动真的有助于缓解抑郁吗？
The best evidence for the effect of exercise on mood comes from one of the largest meta-analyses of data analysed by Cochrane. They looked at data from 30 trials in countries as diverse as Thailand, Denmark and Australia and came to the conclusion that on the whole exercise might have benefits for people suffering from depression, but the effect is very, very small. It’s certainly not the panacea some claim it to be.
关于运动对情绪的影响，最好的证据来自科克兰(Cochrane)进行的一项大规模数据分析。他们从泰国、丹麦、澳大利亚等多个国家的30项实验中提取了数据后得出结论：从整体上讲，锻炼或许的确对患有抑郁症的人有好处，但效果很不明显。由此看来，这显然不是某些人所说的“灵丹妙药”。
