Vitamins Block Some Exercise Benefits

Exercise is good for you. Antioxidants are good for you. But put them together and it’s not as good as you’d think. Because a recent study shows that some vitamins block the beneficial effects of exercise.

A good workout not only gets your heart pumping, it makes your body better able to process glucose and decreases your risk of diabetes. And it does so, in part, by firing up your cells’ mitochondria. Stoking those mitochondrial flames boosts your metabolism. But it also throws off so-called free radicals, which are usually considered harmful. So adding antioxidants—which get rid of free radicals—should make your workout even healthier, right?

Well, no. Forty men took part in a four-week training program. Half the group also received daily doses of Vitamins C and E. The researchers discovered that exercise on its own improves insulin sensitivity, which keeps diabetes at bay. But taking the vitamins erased that gain—findings that appear in the May 12th issue of the Proceedings of the National Academy of Sciences.

So you actually need a burst of potentially damaging radicals to reap some of the important rewards of a good sweat. Which means that even on a molecular level: no pain, no gain.

维生素妨碍某些锻炼益处

锻炼对你有好处，抗氧化剂对你也有好处。不过把这二者合在一起的话，它们的好处并不像你所想象的一样好。这是因为最近的一项研究表明，某些维生素妨碍了锻炼的益处。

好的锻炼不仅让你的心脏活跃起来，而且让你的身体能更好地消化葡萄糖，从而降低糖尿病的风险。锻炼能起到这个作用，部分是因为它能激活你细胞的线粒体。让线粒体活跃起来可以提高你的新陈代谢。但是，锻炼同时也产生所谓的自由基，而自由基一般认为是有害的。那么是不是加一些抗氧化剂——它能消除自由基——就应该使你的锻炼更加健康呢？

不过，答案是否定的。40名男性参加了一个为期4周的训练项目。其中一半的人每天还服用维生素C和E。研究者们发现，锻炼本身就能提高胰岛素的敏感性，这可以防止糖尿病。但是，服用维生素就把这个益处消除了——这项研究结果发表在5月12日的《美国国家科学院院刊》（Proceedings of the National Academy of Sciences）杂志上。

所以，为了获得锻炼的重要回报，实际上你需要一些有潜在害处的自由基的迸发。这就意味着，“不劳无获”即使在分子层面也是对的。

Vocabulary:

Reveal：揭示；显示
Antioxidant：抗氧化的
Vitamin：维生素
Interfere：干扰
Diabetes：糖尿病
Benefit：益处
Workout：锻炼
Glucose：葡萄糖
Decrease：降低
Mitochondria: （植物）线粒体
Boost：提高；增强
Metabolism：新陈代谢
Free radical： 自由基
Insulin：胰岛素
Sensitivity：敏感性
Erase：消除；擦拭
Burst：爆发；突发
Potentially：潜在的
Reap：收割（庄稼）；收获