Just about everyday around 2:00 pm, I can be found catnapping in a chair, at my desk or if I'm lucky, in a sunny spot somewhere. I fall into this semiconscious place where I'm not sound asleep but I'm not fully awake either. I can ease out of this wonderful slumber without a jarring effect - and when I emerge from my nap, some 20 minutes later, I feel so good.
The benefits of napping have been well documented. Research shows how a nap can promote physical well-being, improve mood and memory, re-energize and sharpen senses. Studies show that intellectual performance improves and accuracy in work performance increases too. In fact, fMRI's of nappers showed that brain activity remained higher throughout the day than for those who didn't nap. Furthermore, falling into a light sleep can be meditative. As you nap, the streams of thoughts and feelings can gel together in ways that doesn't happen when you're in a deep sleep.
When you sleep under normal circumstances, your brain cycles through several different stages of Delta, Theta, Alpha, Beta, and Gamma sleep waves. You drift from one stage of sleep to another - from light sleep to deeper sleep, to REM sleep, to wakefulness and so on. Delta and Theta waves are known as Sleep I and Sleep II stages, and are light stages of sleep. So, the key to napping is not to fall into the deeper stages of sleep. That's why a 15 to 30 minute nap is key. Napping more than that will leave you cranky.