Berlin - Two elements of modern working life - long commutes and taking work home at night - are undermining Germans' mental health, according to a landmark study released in Berlin.

People whose work-life balance is out of kilter are twice as likely as the average worker to report in sick due to exhaustion, lack of motivation or headaches, according to the study by Wido, a research unit run by a group of health-insurance funds.

The study highlighted the effects of two worldwide trends: pressure to relocate home for the sake of a good job, and being expected to answer work emails and phone calls while at home.

For 40 percent of the German labour force, the distance between home and work had complicated their living arrangements, the study found, meaning they were only home at weekends, spent more than an hour a day on commutes, or had relocated for the sake of work.

A Wido survey also found that one tenth of Germans were taking work from the office to do at home.

Workers were being flexible as employers demanded, but were putting their own wellbeing as risk, the report found.

“You need to put limits on flexibility,” said Helmut Schroeder, the lead author, in Berlin.

The Wido data was based on nationwide records of days lost to sickness. Doctors link exhaustion and headaches to psychological malaise.

The findings feed into a growing debate in Germany about whether the hard-work habits which Chancellor Angela Merkel has been recommending to eurozone neighbours to escape from debt have lowered Germans' quality of life. - Sapa-dpa