Want to get some sleep and boost job performance by 34 percent? "Take a 26-minute nap," says Sara Mednick, research scientist at the University of California at San Diego and author of Take a Nap! Change Your Life. Studies show that one nap of up to 90 minutes between the hours of 1:00 and 4:00 P.M. will reduce your sleep debt, invigorate your day, boost your job performance, and not affect night sleep, says Mednick.

"To start, lie down at the same time every day for 20 minutes without the expectation of falling asleep," she says. "That way, you're teaching your body that it's okay to relax in the middle of the day." Eventually your body will believe you, and you'll doze off. Set your watch or cell phone to wake you up—and feel free to expand the time to sleep.