A three-day-week gets the best performance from workers aged over 40, a study has found.

一项研究发现，40岁以上的人如果每周上三天班，工作表现最佳。

Researchers found the cognitive¹ performance of middle-aged² people improved as the working week increased up to 25 hours a week.

研究人员发现，当中年人每周工作时间达到25小时，认知表现将有所改善。

However, when the week went over 25 hours, overall performance for the test subjects decreased as "fatigue³ and stress" took effect.

然而，如果每周工作时间超过25小时，受试者的整体表现则将恶化，因为“疲劳和压力”开始产生影响。

The report, which was published in the Melbourne Institute Worker Paper series, invited 3,000 men and 3,500 women in Australia to complete a series of cognitive tests while their work habits were analysed.

发表在《墨尔本研究院工人报》的这篇研究报告邀请了澳大利亚的3000名男性和3500名女性来完成一系列认知测试，同时分析他们的工作习惯。

It was found those working 25 hours a week performed best while those working 55 hours a week showed results worse than retired⁴ or unemployed⁵ participants.

研究发现，每周工作25小时的人表现最佳，而每周工作55小时的人的测试成绩比那些退休或待业的人还糟。

One of the three authors, Professor Colin McKenzie from Keio University told the Times: "Many countries are going to raise their retirement⁶ ages by delaying the age at which people are eligible⁷ to start receiving pension benefits. This means that more people continue to work in the later stages of their life.

该研究报告的三位作者之一、来自日本庆应义塾大学的科林•麦肯齐教授告诉《泰晤士报》说：“许多国家都预备提高退休年龄，让人们延迟领取养老金。这意味着更多人在中晚年还要继续工作。

"The degree of intellectual stimulation⁸ may depend on working hours. Work can be a double-edged sword, in that it can stimulate⁹ brain activity, but at the same time long working hours can cause fatigue and stress, which potentially damage cognitive functions.

“智力被激发的程度可能取决于工作时长。工作是一把双刃剑，既能够刺激大脑活动，同时过长的工作时间也会导致疲劳和压力，并有可能损害认知功能。

"We point out that differences in working hours are important for maintaining cognitive functioning in middle-aged and elderly adults. This means that, in middle and older age, working part-time could be effective in maintaining cognitive ability."

“我们指出了不同工作时长的区别所在，这对于保持中老年人的认知功能具有重要意义。这意味着，在中晚年，从事兼职工作将能有效地保持认知能力。”

The research comes amid moves to edge the British state pension age closer to 70.

研究发布正值英国计划将法定退休年龄提高到将近70岁。

Currently for someone born in 1989, a state pension begins at the age of 68.

根据目前的法规，1989年出生的人要到68岁才能领到养老金。