Angela Merkel might be calling the southern Europeans lazy these days. But German union leaders are calling for their compatriots to emulate them in at least one way: by taking siestas.

The DGB confederation of trade unions argues that a short, lunchtime power nap makes sense for health and performance reasons. "Even though the siesta is something that isn't a given anymore in the southern European countries, it is still a good idea for health reasons," said Annelie Buntenbach, a DGB executive board member. "A short afternoon nap reduces the risk of, for example, a heart attack, and provides an energy boost," she told Tageszeitung in an interview.

Studies bear this out. Researchers at the Harvard School of Public Health and the University of Athens Medical School in Greece found that Greek workers who took regular siestas had 37% lower mortality rates from coronary illnesses than their napless counterparts.

The idea has caught on in Germany, where big German companies such as BASF, Opel, Hornsbach and Lufthansa provide special rooms for their workers, and employers say they benefit from the increased productivity of well-rested employees.

"An afternoon nap bridges the power low (of midday) with its heightened risk of errors," said Jürgen Zulley, a professor of biology and psychology at the University of Regensburg. "A nap can help us to react faster, be more alert, remember things better and put us in a better mood."

A study last year at the University of California Berkeley backed that up by demonstrating that healthy young adults performed better at learning task towards the end of the day if they had taken an afternoon nap.

Germans used to take siestas up until the industrial revolution. But the labour needs of the manufacturing economies caused the custom to die out in much of northern Europe. It has been a diminishing custom in the south as well over the past two decades, one some are trying to bring back.

But not everyone is in favour. "We have already a half-hour break for breakfast and half-an-hour for lunch," said Frank Pahlow, a Berlin electrician. "If we had longer breaks to nap, we would get home much later, which would be really bad. It's different in Spain and Italy, where you need a nap because it's so hot, but here in Germany, we don't even have proper summers."

But some workers say they would jump at the chance of a midday recharge. "Sometimes I really need a nap, but I've never taken one at work," said healthcare worker Nils Gordon de Mello, also in Berlin. "If there was a room at work where you could go and lie down for a bit in the afternoon that would be great."