咖啡因有助于夏日锻炼

Good news for coffee, tea, and cola lovers: Caffeine may be the perfect complement to your summer workouts. Several recent studies have found that a small dose before exercising helps improve performance, and a few cups of the strong stuff after a tough workout can help your muscles recover more quickly.

对咖啡、茶、可乐爱好者的好消息:咖啡因可能是夏季锻炼时最理想的补充剂。近期几项研究发现,在运动前摄取少量咖啡因有助于提升训练效果,而在训练后能够喝上几杯浓咖啡因饮料则有助于肌肉尽快恢复。

A pre-workout jolt训练前少量摄取

In a recent Australian study of both recreational and advanced runners, those who took about 95 milligrams of caffeine (about the equivalent of an eight-ounce cup of coffee) improved their 5K times by an average of 10 to 12 seconds.

近期澳大利亚一份对业余和专业跑步选手的研究表明,运动员摄入95毫克咖啡因(相当于8盎司的咖啡)后,跑完5千米路程的时间平均减少了10-12秒。

Back in May, Spanish researchers reported that hot, dehydrated cyclists who downed caffeine with their water and carbs could pedal harder for a longer time in steamy weather—the first study to specifically simulate summertime temperatures. The scientists think caffeine stimulates muscles, thereby helping to offset heat-related fatigue.

早在5月,西班牙研究人员报告表明,如果体温升高、脱水的骑车人摄入咖啡因和碳水化合物,在湿热的天气里能够坚持更长的时间——这是首次在模拟夏天气温的环境下进行的研究。科学家认为咖啡因能够刺激肌肉,从而抵消热量消耗带来的疲劳。

Postexercise refueling在运动后补充能量

Another Australian study found that glycogen, the muscles primary fuel source during exercise, is replenished more quickly when athletes ingest both carbohydrate and caffeine following high-intensity workouts. Cyclists who drank large amounts of caffeine (five to six strong coffee cups worth!) along with carbs had 66% more glycogen in their muscles four hours after biking until exhausted, compared to when they consumed carbohydrate alone.

另一项澳大利亚的研究发现,运动时肌肉的主要燃料来自糖元。高强度锻炼后,当运动员同时摄取碳水化合物和咖啡因饮料时,糖元会更快得到补给。那些摄入大量含有咖啡因的碳水化合物饮料的(相当于5到6杯浓咖啡)自行车运动者,在骑车耗尽体力四小时之后,肌肉中糖元的含量比只摄入碳水化合物的运动者要高66%。

It seems that caffeine may speed up the blood's transportation of glucose to the muscles. But much caffeine can make you jittery and disrupt sleep。

看来,咖啡因可以使血液中的葡萄糖加速流动到肌肉中,但是太多的咖啡因会让你神经紧张或睡眠紊乱。

The truth about caffeine咖啡因的真相

But wait - aren't we warned against consuming too many caffeinated beverages, especially when we're out in the heat? Ive always heard that caffeine can be dehydrating, so I posed the question to Nancy Clark, RD, author of the Sports Nutrition Guidebook, Fourth Edition (2008).

等等——我们不是被告知在炙热的室外环境里要少喝含咖啡因太多的饮料吗?我常常听说咖啡因会使人脱水,带着这样的疑问我咨询了《运动营养指南 第四版》(2008)的作者南希•克拉克。

''While once deemed true, we now know that coffee is not dehydrating,' Clark tells me. 'The truth is, a moderate intake of coffee, cola, and other caffeinated beverages do count toward fluid needs, particularly if you are accustomed to consuming caffeine as part of your daily diet.''

“这一度被认为是真的,但我们现在知道咖啡并不会让人体脱水,”克拉克告诉我:“事实是,适量摄入咖啡、可乐和其他含咖啡因的饮料对体内水分需求有重要的意义,特别是当我们已经习惯把摄入咖啡因当成日常饮食一部分的时候。”

Besides waking you up, caffeine also stimulates the brain and improves concentration; theres even evidence that drinking coffee may help you live longer, and even smelling it may relieve stress. But be careful just how much caffeine youre getting and where it's coming from: While black coffee and plain tea have no calories, extras like cream, sugar, and flavored syrups - especially in large serving sizes - can quickly counteract your fitness goals.

除了让你意识清醒,咖啡因也会刺激大脑并提高注意力;甚至有事实表明饮用咖啡可以让你长寿,即使是闻一闻也会让你放轻松。但是你要注意每天摄入咖啡因的量及其来源:黑咖啡和清茶是没有热量的,调味添加品如奶油、糖和调味糖浆——特别是那种大份量的——会迅速破坏你的健身目标。

Plus, every person reacts to caffeine differently, regardless of dosage. 'Don't just assume you will perform better with a caffeine boost: You might just end up nauseated, coping with a 'coffee stomach,' or suffering from caffeine jitters at a time when you are already nervous and anxious,' Clark warns. 'Experiment during training to determine if a caffeinated beverage or plain water is your best bet.'

另外,不管饮用多少,每个人对咖啡因的反应是不同的。“不要设想你在咖啡因的刺激下会表现的更好:最终你可能会感到恶心,忙着处理‘咖啡胃,在你紧张和焦虑的状态下还要遭受咖啡因过敏症”克拉克警告说,“在训练过程中你应该通过试验来决定你的最好选择是含咖啡因的饮料还是纯水。”

A moderate caffeine intake is considered to be about 250 milligrams per day, or two to three cups of coffee daily; most experts agree that a cup or two of java or iced tea - an hour before your daily walk, run, or workout session - can make the task seem easier.

一般认为,每天摄入250毫克咖啡因或者是每天2到3杯咖啡是适量的。很多专家赞同你在每天散步、跑步或者锻炼前一个小时——喝一两杯爪哇茶或者冰茶——会让你的运动变得更加轻松。

Is coffee, cola, or tea part of your daily routine? Have you noticed whether caffeine helps fuel your workouts or recovery?

咖啡,可乐或茶是你日常生活的一部分吗?你是否注意到咖啡因对你的锻炼或者体能恢复有帮助呢?