People who do not drink enough water have a stronger biological response to stress, according to a study.

一项研究表明，饮水不足的人对压力的生物反应更强烈。

Researchers found those who habitually drink less release greater levels of the stress hormone cortisol, despite not feeling any thirstier than people who drink more.

研究人员发现，尽管那些习惯性少喝水的人并不比多喝水的人感觉更口渴， 尽管并不比喝得多的人更渴。

The study, led by experts at Liverpool John Moores University (LJMU), included 16 people who drank under 1.5 litres of water a day, along with 16 people who regularly met daily recommended guidelines for fluid intake.

这项由利物浦约翰摩尔斯大学（LJMU）的专家领导的研究，纳入了16名每天饮水量低于1.5升的人， 以及16名经常达到每日推荐饮水量的人。

European Food Safety Authority guidelines recommend that men should drink 2.5 litres of water a day while women should drink two litres.

欧洲食品安全局指南建议，男性每天应饮用2.5升水，女性应饮用2升水。

What the study involved

研究内容

Researchers monitored hydration in both groups over seven days using urine and blood samples, after which they were invited into the lab for a stress test.

研究人员通过尿液和血液样本对两组人在七天内的水分状况进行了监测， 之后邀请他们到实验室进行压力测试。

The test involved a job interview, for which each individual was given ten minutes to prepare for.

测试内容为一场求职面试，每个人有十分钟时间准备。

After that time, they were invited into another room where a fake camera was set up and asked to do the interview to a panel of three people dressed in white coats.

十分钟后， 他们被邀请进入另一个房间，那里设置了一台假摄像机，并要求他们向三位穿着白大褂的人组成的评审团进行面试。

Following the fake interview, individuals were then asked to do a mental maths challenge which involved subtracting numbers as fast as they can.

假面试结束后，参与者还需完成一项心算挑战，即尽可能快地进行减法运算。

Professor Neil Walsh, of the LJMU School of Sport and Exercise Sciences, described the test as "really flustering".

利物浦约翰摩尔斯大学运动与锻炼科学学院的尼尔·沃尔什教授称，这项测试“着实令人慌乱不已”。

What is cortisol?

什么是皮质醇？

Cortisol, known as the stress hormone, is produced by the adrenal glands in response to stress and also plays a role in immune response, metabolism and blood pressure.

皮质醇是一种应激激素，由肾上腺在应对压力时产生，同时也在免疫反应、 新陈代谢和血压调节中发挥作用。

The team found cortisol levels were higher in those who drank less.

研究团队发现，少喝水的人皮质醇水平更高。

Professor Walsh said: "We know that people who have a low daily fluid intake, who don't meet the recommendations, are likely to be poorly hydrated.

沃尔什教授说：“我们知道，那些每日饮水量低、未达到推荐量的人，很可能处于脱水状态。

"But what we didn't know was whether, when you then stress those people under controlled conditions, they would have a greater stress hormone response."

“但我们不知道的是，当你在可控条件下对这些人群施加压力时， 他们是否会产生更强烈的应激激素反应。”

Researchers collected saliva samples from the group before and after the stress test to measure cortisol levels.

研究人员在压力测试前后采集了该组人群的唾液样本，以测量皮质醇水平。