This is exactly what I’ve been doing, limiting the Power Naps to 25 minutes maximum based on something I read a while ago. The Men’s Journal article says:
Here’s how the power nap works: Sleep comes in five stages that recur cyclically throughout a typical night, and a power nap seeks to include just the first two of them. The initial stage features the sinking into sleep as electrical brain activity, eye and jaw-muscle movement, and respiration slow. The second is a light but restful sleep in which the body gets ready — lowering temperature, relaxing muscles further — for the entry into the deep and dreamless “slow-wave sleep,” or SWS, that occurs in stages three and four. Stage five, of course, is REM, when the eyes twitch and dreaming becomes intense.
The five stages repeat every 90 to 120 minutes. Stage one can last up to 10 minutes, stage two until the 20th minute. Extenuating circumstances, like manning the controls of a jet, aside, experts believe that the optimal power nap should roughly coincide with the first 20 minutes in order to give you full access to stage two’s restorative benefits. In addition to generally improving alertness and stamina, stage two is marked by a certain electrical signals in the nervous system that seem to solidify the connection between neurons involved in muscle memory. “It’s like a welding machine,” says Mednick. “When you wake up, your neurons perform the same function as before, but now faster and with more accuracy,” making the 20-minute nap indispensable to the hard-working athlete looking to straighten out his putter or baseline shot.
Men’s Journal explains how to take a nap: Snooze, You Win. We learn that there are five types of naps:
- THE NANO-NAP: 10 to 20 seconds Sleep studies haven’t yet concluded whether there are benefits to these brief intervals, like when you nod off on someone’s shoulder on the train.
- THE MICRO-NAP: two to five minutes Shown to be surprisingly effective at shedding sleepiness.
- THE MINI-NAP: five to 20 minutes Increases alertness, stamina, motor learning, and motor performance.
- THE ORIGINAL POWER NAP: 20 minutes Includes the benefits of the micro and the mini, but additionally improves muscle memory and clears the brain of useless built-up information, which helps with long-term memory (remembering facts, events, and names).
- THE LAZY MAN’S NAP: 50 to 90 minutes Includes slow-wave plus REM sleep; good for improving perceptual processing; also when the system is flooded with human growth hormone, great for repairing bones and muscles.
I prefer a 10-minute mini-nap.