According to Jesse Hanley, M.D., the reason we need an afternoon break is that most of us are walking around with burned-out systems. We've completely depleted our adrenal glands, a pair of thumb-size endocrine organs on top of our kidneys that plays a crucial role in maintaining energy levels. "Between 3 and 5 P.M., the adrenals are in decline toward a nighttime pattern," says Hanley. "The more exhausted our adrenals are [i.e., the more stressed-out we are], the bigger the crash we have at that time of day." If we don't nap, we experience anxiety or reach for a stimulant—sugar, carbohydrates or caffeine—in an attempt to get through the adrenal drain. "It's very clear that renewal processes, such as restoring the adrenals, only happen when we sleep," says Hanley. "If people were willing to take 15 to 30 minutes, put their feet up, close their eyes and give in to what their body was really asking for, they would have that time of ultimate repair." Other sleep experts add that naps can help you become more creative and productive. I've found this to be true as well. More often than not, I've emerged from a nap with a solution to a problem that I had been struggling with.

Napping requires discipline, and that takes time to develop. I worked at it for more than a year before I learned how to de-stress enough to nap. Here's what you can do to get started:

• Pinpoint the moments when you need to relax your mind. If you pay attention, you'll see there are times when you just don't feel like you're all there.


• Go to a spot where you can sit comfortably—you don't have to lie down to relax, and many of us can't recline at work anyway.


• Shut off the lights and the ringer on the phone, if you can. Eye masks are also good for getting in the mood.


• Set your alarm for 10 minutes at first, 20 if you're at home or can take more time. I find that if I nap for much longer than 30 minutes, I feel sluggish for quite a while.


• Close your eyes. Scan your body for tension and begin to let go. If your mind races, gently begin to let your attention fall to the center of your heart and try to follow your breathing as it passes there. Relax. Hold your attention very loosely.

That's it. You may drift off or you may not, but after about ten minutes you should feel a little more refreshed. As you begin to feel more comfortable with napping, increase the length of your sessions.

I still don't sleep deeply when I nap. For me the point is to try to let go of whatever is keeping me awake. I lie down or sit still, depending on where I am, with my eyes closed; no matter what urges I have, I don't move for at least ten minutes. If I have to set an alarm to make myself less anxious about drifting off, I set one. Those few minutes of quiet are more refreshing than being in a nice, clean pool on a hot summer day.

I could go on, but right now it's four o'clock. It's time for my nap. Don't tell my boss.

Next: 5 good reasons to take a nap