研究：运动前喝杯咖啡可以加速脂肪燃烧

阳春四月不减肥，春暖花开肉一堆。想甩掉陈年老肥，当然要运动起来！研究发现，如果在运动之前喝上一杯咖啡，就可以加速脂肪燃烧。这是真的吗？

If you're looking to maximize the amount of fat burned in your next workout, think about having a coffee half an hour before you get started – as a new study suggests it can make a significant difference to fat burning, especially later on in the day.

如果你希望下一次锻炼时最大化地提高脂肪燃烧量，不妨考虑在运动前半小时喝杯咖啡——因为有新研究表明，它可以使脂肪燃烧量明显变化，尤其是在下午。

Researchers found that 3 milligrams of caffeine per kilogram of body weight  can boost the rate of fat burning during aerobic exercise, based on results gathered from 15 male volunteers.

研究人员收集了15名男性志愿者的数据后发现，如果按每公斤体重3毫克的量来摄入咖啡因，就可以提高有氧运动中的脂肪燃烧速度。

The coffee dose was shown to increase maximal fat oxidation rate (a measure of how efficiently the body burns off fat) by an average of 10.7 percent in the morning and 29 percent in the afternoon.

研究表明，咖啡可以增加最大脂肪氧化率，上午平均增加10.7%，下午增加29%。最大脂肪氧化率用于衡量身体有效燃烧脂肪的效率。

"The recommendation to exercise on an empty stomach in the morning to increase fat oxidation is commonplace," says physiologist Francisco José Amaro-Gahete from the University of Granada in Spain. "However, this recommendation may be lacking a scientific basis, as it is unknown whether this increase is due to exercising in the morning or due to going without food for a longer period of time."

“早上空腹运动以增加脂肪氧化的说法很常见，”西班牙格拉纳达大学的生理学家弗朗西斯科·何塞·阿马罗-加赫特说，“然而，这一建议可能缺乏科学依据，因为不知道脂肪燃烧量增加是由于早上运动还是由于长时间不进食。”

The researchers were also keen to look in closer detail at the relationship between caffeine and exercise. The stimulant is often associated with improved athletic performance, though the science behind this link isn't as comprehensive as it could be.

研究人员也很想更细致地考察咖啡因与运动之间的关系。咖啡因经常和运动表现改善相关联，尽管这种联系背后的科学根据并不多。

Across the course of four weeks, the 15 volunteers in the study went through four tests in a random order: taking a placebo at 8 am, taking a placebo at 5 pm, taking a caffeine supplement at 8 am, and taking a caffeine supplement at 5 pm.

在四周的时间里，参与研究的15名志愿者以随机顺序进行了4组测试：早上8点服用安慰剂；下午5点服用安慰剂；早上8点服用咖啡因补充剂；下午5点服用咖啡因补充剂。

In subsequent cycling tests after the stimulant or placebo had been given, the fat-burning capability of the body was measured, showing the impact that caffeine had made on MFO. Maximum oxygen uptake was also boosted, as was the intensity of exercise.

在服用咖啡因补充剂或安慰剂后的骑车测试中，研究人员测量了志愿者身体的脂肪燃烧能力，揭示出咖啡因对最大脂肪氧化率的影响。研究人员发现，志愿者的最大摄氧量也得到了提升，运动强度也加大了。

"The results of our study showed that acute caffeine ingestion 30 minutes before performing an aerobic exercise test increased maximum fat oxidation during exercise regardless of the time of day," says Amaro-Gahete.

阿马罗-加赫特说：“我们的研究结果表明，在进行有氧运动测试前30分钟快速摄入咖啡因，无论在一天当中的什么时候，都能增加运动过程中的最大脂肪氧化量。”

This is a study with a fairly small sample of participants, so it's important not to jump to too broad a conclusion, but the results are clear enough to suggest that there is some kind of association there.

由于该研究样本量过小，所以还不清楚结论是否具有普遍性，但可以明确的是，咖啡因和脂肪燃烧之间存在某种关联。

"Overall, these results suggest that a combination of acute caffeine intake and exercise at moderate intensity in the afternoon provides the best scenario for individuals seeking to increase whole-body fat oxidation during aerobic exercise," the researchers conclude.

研究人员总结道：“总体来说，这些结果表明，急性咖啡因摄入和下午中等强度的运动相结合，为那些希望在有氧运动中加速全身脂肪燃烧的人提供了最佳方案。”

The research has been published in the Journal of the International Society of Sports Nutrition.

这项研究被发表在《国际运动营养学会杂志》上。