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.

維生素妨礙某些鍛煉益處

鍛煉對你有好處，抗氧化劑對你也有好處。不過把這二者合在一起的話，它們的好處并不像你所想象的一樣好。這是因為最近的一項研究表明，某些維生素妨礙了鍛煉的益處。

好的鍛煉不僅讓你的心臟活躍起來，而且讓你的身體能更好地消化葡萄糖，從而降低糖尿病的風險。鍛煉能起到這個作用，部分是因為它能激活你細胞的線粒體。讓線粒體活躍起來可以提高你的新陳代謝。但是，鍛煉同時也產生所謂的自由基，而自由基一般認為是有害的。那么是不是加一些抗氧化劑——它能消除自由基——就應該使你的鍛煉更加健康呢？

不過，答案是否定的。40名男性參加了一個為期4周的訓練項目。其中一半的人每天還服用維生素C和E。研究者們發現，鍛煉本身就能提高胰島素的敏感性，這可以防止糖尿病。但是，服用維生素就把這個益處消除了——這項研究結果發表在5月12日的《美國國家科學院院刊》（Proceedings of the National Academy of Sciences）雜志上。

所以，為了獲得鍛煉的重要回報，實際上你需要一些有潛在害處的自由基的迸發。這就意味著，“不勞無獲”即使在分子層面也是對的。

Vocabulary:

Reveal：揭示；顯示
Antioxidant：抗氧化的
Vitamin：維生素
Interfere：干擾
Diabetes：糖尿病
Benefit：益處
Workout：鍛煉
Glucose：葡萄糖
Decrease：降低
Mitochondria: （植物）線粒體
Boost：提高；增強
Metabolism：新陳代謝
Free radical： 自由基
Insulin：胰島素
Sensitivity：敏感性
Erase：消除；擦拭
Burst：爆發；突發
Potentially：潛在的
Reap：收割（莊稼）；收獲