Everyone knows the feeling. You're back from lunch and supposedly refreshed after taking a break from staring at your computer. But, instead you're fighting off a creeping sleepiness and reaching for another cup of coffee to snap out of that lethargy.

The next time you feel you're about to nod off and happen to be in Frankfurt, head for the city's "Cinestar Metropolis" movie theater.

There for €5.50 ($7.15), weary office workers can sink into one of the many large comfortable armchairs in the darkened theater and close their eyes.

Instead of a movie, soft music and the murmuring of waves wash over the room, lulling the city's lunch-heavy work force to sleep.

To ensure that the naps don't end up incapacitating the workers by turning too deep, a soft voice at the end of the half-hour session gently nudges them out of their slumber.

Increasing productivity

The power-napping-in-meditative-ambience concept is working well according to Stefan Burger, head of the movie theater. He pointed out that that the relaxing break worked to the advantage of employers, because studies had shown that it increased the concentration and productivity of workers.

For those seeking relaxation with a not-so-full stomach, the Cinestar Metropolis also offers a lunch package packed with vitamin-rich ingredients.

If you're considering whether it's worth convincing your boss about the merits of power napping, here's an argument you could use: Albert Einstein is said to have been a die-hard fan of post-lunch power siestas.