A 20-minute nap twice a week is the standard at Nationwide Planning Associates Inc. in Paramus, where an old storage closet has been transformed into the office's "rejuvenation center." Inside, employees can get some shut-eye or just escape from the work day for a while.

The rejuvenation center is open to Nationwide Planning Associates employees twice a week. (James Colleary, Nationwide Planning Associates)

"We wanted to develop something that would boost employee morale, while at the same time increasing productivity," explained James Colleary, who helped create the nap system. "To be honest, it not only met, but exceeded our expectations."

Colleary said employees are happier when they exit the special room, and they work harder in the second half of the day.

"Another bonus we have - noticeably less employee turnover, which is always good," he added.

Shorter Naps Can Increase Alertness

Sindhu Syamaprasad, sleep center coordinator at Saint Barnabas Medical Center in Livingston, praised the midday nap concept.

"I wish a lot more places implemented that," she said.

Syamaprasad said 20 minutes is optimal for someone who wants to increase their alertness, memory and performance. She cautioned, though, against getting more than 20 minutes of sleep. "Sleep inertia" could set in, resulting in grogginess and disorientation.

A poll from the National Sleep Foundation found more than 40 percent of Americans in the 13-to-64 range rarely or never get a good night's sleep during the week. The reasons for lack of sleep vary by age group, Syamaprasad said.

"Ideally, you should try to go to bed at a certain time," she advised. "Try not to do any vigorous exercise before bedtime."

Syamaprasad also advised against technology in bed. She said watching television or fiddling with your cell phone doesn't help the brain rest.

"Only lay down when you're ready to go to sleep," she said.