天气炎热出汗多，可以多喝运动饮料吗?

很多人会觉得夏天出汗多，可以喝运动饮料补充电解质。但也有人在大量饮用运动饮料后，感到心跳加速、身体不适。这是为什么呢？什么情况下更适合饮用运动饮料补充电解质？美国乔治华盛顿大学米尔肯研究所公共卫生学院急诊医生、卫生政策与管理教授莱纳·温给出了解答。

在回答这些问题前，我们需要先了解什么是运动饮料，以及运动饮料和能量饮料的区别。

What are sports drinks? How are they different from energy drinks, and what ingredients do they each contain?
什么是运动饮料？它们与能量饮料有何不同，两种饮料都含有哪些成分？

Dr. Leana Wen: It’s important to distinguish between sports drinks and energy drinks.
温：区分运动饮料和能量饮料很重要。

Sports drinks are electrolyte-enhanced beverages. Their main purpose is to restore water and electrolytes that are lost during heavy exercise and sweating. They will contain electrolytes like sodium, potassium, calcium and magnesium. Many are carbohydrate-based, with added sugars like fructose, glucose and sucrose. Sometimes they contain caffeine.
运动饮料是电解质补充饮料。主要目的是补充在剧烈运动和出汗过程中流失的水分和电解质。运动饮料含有钠、钾、钙和镁等电解质，碳水化合物含量通常很高，添加了果糖、葡萄糖和蔗糖等糖。有时含有咖啡因。

There are also energy drinks that are often, and unfortunately, confused with sports drinks. Energy drinks typically contain large amounts of caffeine. Many contain other legal stimulants like taurine, guarana and L-carnitine. These energy drinks could reduce fatigue and enhance performance in the short term. However, they are not sports drinks and should not be used when the purpose is to replenish electrolytes and fluids.
人们常常把运动饮料和能量饮料混淆。能量饮料通常含有大量的咖啡因。许多含有其他合法兴奋剂，如牛磺酸、瓜拉纳和左旋肉碱。这些能量饮料可以在短期内缓解疲劳，有提神效果。然而，能量饮料不是运动饮料，如果仅仅为了补充电解质和水分时，不应饮用能量饮料。

According to the US Centers for Disease Control and Prevention, 1,499 adolescents ages 12 to 17 went to the emergency room for an energy-drink related emergency in 2011. High amounts of caffeine can induce irregular and rapid heartbeats. Individuals may become anxious and develop sleeping problems. Those consuming energy drinks instead of sports drinks or water may become dehydrated. Also, although many ingredients in these energy drinks are marketed as being “natural,” they may be present in much larger quantities that people normally consume.
美国疾病控制和预防中心数据显示，2011年，1499名12至17岁的青少年因能量饮料相关紧急情况前往急诊室。大量的咖啡因会导致心律不齐和心跳加快。可能会导致焦虑并出现睡眠问题。用能量饮料代替运动饮料或水饮用，可能导致脱水。此外，尽管能量饮料中的许多成分被宣称是“天然”的，但它们的含量可能比人们平常的摄入量大得多。

The American Academy of Pediatrics recommends that children and adolescents do not use energy drinks.
美国儿科学会建议儿童和青少年不要饮用能量饮料。

cnn: Is it good to have caffeine in a sports drink, and how much is too much?
美国有线电视新闻网：在运动饮料中加入咖啡因好吗？多少才算太多？

Wen: The primarily reason for using a sports drink is to replenish electrolytes and fluids. Caffeine does not have a role in replenishing electrolytes, and in fact is a diuretic that leads to more fluid being lost, so in general, I would advise to stay away from sports drinks that have caffeine.
温：饮用运动饮料的主要原因是为了补充电解质和水分。咖啡因在补充电解质方面没有作用，事实上它是一种利尿剂，会导致更多的水分流失，所以总的来说，我建议远离含有咖啡因的运动饮料。

Some adult athletes may choose drinks with caffeine as an added boost to their performance. If so, they should be aware of the risk and of exactly how much they are using. Caffeine is a stimulant that can increase heart rate and have adverse effects on performance, too. It also has addictive potential. 
一些成年运动员可能会选择含有咖啡因的饮料来提高状态。如果是这样的话，他们应该意识到风险以及他们到底饮用了多少。咖啡因是一种兴奋剂，可以提高心率，也会对人的状态产生不利影响，还可能导致成瘾性。

The negative impacts of caffeine are even more profound when it comes to young people. The American Academy of Pediatrics recommends that children under 12 do not consume any caffeine. Children ages 12 to 18 should not exceed 100 milligrams of caffeine every day.
咖啡因对年轻人的负面影响更为深远。美国儿科学会建议12岁以下的儿童不要摄入任何咖啡因。12至18岁的儿童每天摄入的咖啡因不应超过100毫克。

Parents should keep in mind that there are other beverages that contain caffeine, including coffee and many sodas, and that many sports drinks contain very high levels of caffeine that would far exceed the daily recommended amount. Given that sports drinks really are intended to replace electrolytes and not to be used as a stimulant, it’s best for children to avoid sports drinks with added caffeine.
家长们应该记住，还有其他饮料含有咖啡因，包括咖啡和许多苏打水，许多运动饮料含有非常高水平的咖啡因，远远超过每日推荐量。考虑到运动饮料主要功能是补充电解质，而不是用作兴奋剂，儿童最好避免饮用添加咖啡因的运动饮料。

cnn: Who needs sports drinks, and who should stay away?
美国有线电视新闻网：谁需要运动饮料，谁应该远离？

Wen: Most people do not need sports drinks. Water is sufficient for hydration, and the food people eat will usually contain the electrolytes they need. Athletes engaging in mild to moderate activity and children playing on the playground or engaging in recreational after-school sports generally do not need additional electrolyte replacement drinks.
温：大多数人不需要饮用运动饮料。喝水补充水分就足够了，平时摄入的食物通常也含有人体所需的电解质。从事轻度至中度活动的运动员、在操场上玩耍或从事娱乐性课后运动的儿童通常不需要额外的电解质补充饮料。

If it’s hot outside, they need to be drinking lots of water before, during and after exercise. They can also aim to eat foods packed with nutrients and electrolytes. Some examples include watermelon, milk, cheese, bananas, coconut water and avocados. If they are engaging in heavier activity for longer, they could also eat a snack of salted nuts.
如果外面很热，他们需要在运动前、运动中和运动后大量喝水。还可以吃富含营养和电解质的食物，例如西瓜、牛奶、奶酪、香蕉、椰子水和鳄梨。如果长时间从事重体力活动，也可以吃一些咸坚果零食。

Individuals who should consider sports drinks are athletes who are doing vigorous exercise for at least an hour or longer. Whether they need it depends on the climate, type and intensity of exercise, and whether they are prone to sweat heavily.
进行至少一小时或更长时间剧烈运动的运动员，应该考虑饮用运动饮料。具体取决于气候、运动类型和强度，以及是否容易出汗。