Like most things the key aspect for naps is timing - When you do it and for how long.
But the ideal nap also depends on your age, your activity patterns and probably your genetics.
Most people have experienced the fully range of nap outcomes - The Good Nap, the Bad Nap and the Downright Ugly Nap - and it shows!
Good napping takes practice, patience and planning rather than spontaneity. You need to deliberately manage the whole process - when you plan to nap, its duration and how you will eliminate disturbances, and how to wake up when you have finished the nap period.
This article explores how to get the perfect nap and get maximum benefits from napping.
There are three main stages of sleep through which the brain cycles in episodes of every 90-120 minutes.
If you take a nap and wake up during the middle phase - Slow-Wave Sleep,you will experience what is called sleep drunkenness or sleep inertia. Most people have experienced this as a groggy, disordered and unrested feeling. Its not nice. It defeats the purpose for having a nap.
The perfect outcome for your nap depends on what you want to achieve and how long you have before you expect to be undisturbed. The perfect nap is an undisturbed nap that you have perfect control over, and a nap from which you wake up at the end of a sleep cycle. Disturbed naps have unknown and unpredictable outcomes as you don't know in which part of the sleep cycle you will be awoken. This applies whether or not you are the cause of the disturbance. It is worse when someone else or something wakes you up before you have finished the nap.
The general consensus is that the best time to nap is in the afternoon (1-4 PM), which corresponds with Siesta time for many people around the world. Napping later in the afternoon can interfere with normal sleep patterns at night. The normal circadian rhythms generally dictate that the body will expect to be awake in the morning and early evening. So early afternoon, after lunch appears to be the nest time.
There are three common nap durations that generally produce different outcomes:
15 minute Nap - Good for a quick Re-charge and Refresh of Alertness. This requires a 10-20 minute deep nap. It would be nice to get more time, but several research studies have shown that 10-20 minutes is probably the optimal in terms of cost and benefit. Short duration naps can do wonders for how you feel, but if you start dreaming your naps are probably too long and you risk waking up feeling groggy and even worse.
60 minute Nap - Good for a partial tone up of brain function and memory processing. This generally requires a 60-minute nap. This is because a full cycle of the sleep phases can be completed. But there is always a risk of grogginess when you wake up, especially if you wake up during a slow-wave period. You cannot control the sleep phases nor their length, but longer naps are generally better because you can generally complete a cycle.
90 minute Nap - Good for getting the full benefits of a nap. This will generally guarantee one or more full cycles of sleep and this means there is less chance of sleep inertia. These long naps, especially if you are very tired, can help restore creativity and focus, boost memory and enliven your emotional state. If you happen to waking up during or just after the final phase the REM sleep, there is less risk of sleep inertia. You will already be rested. This may be the perfect nap but few of us has the time for these long naps in a busy cycle. Many people can not nap for that amount of time.
Research has shown that the benefits of long and short naps vary considerably, and these studies challenge the notion that long naps are better than short ones. Most people don't have time for long naps and this probably biases the findings from these studies. Most people focus on getting the best they can from a short nap.
Studies conducted in Australia have confirmed that short naps are generally better for most people. Subjects were tested using a variety of mental alertness tasks after napping for periods ranging from 30 seconds to half an hour.
The alertness tests peaked at a duration of 10 minutes and the benefits lasted for about 2 hours after the nap. So this suggested that the 10-minute nap was beneficial.
Many subjects who napped for 20-30 minutes reported feeling groggy for about 30 minutes after their naps. After this initial decline, their alertness recovered to be similar to those people who napped for 10-20 minutes. So the shorter naps were better overall.
Another study showed that improved thinking and memory function required the slow-wave sleep that is generally only achieved by 60-minute nap. But many people cannot stay asleep for that period of time, and most people don't have that luxury. So it appears that the best practical nap to aim for is 10-20 minutes, and up to 60 minutes if you have the time and can stay asleep for that long.
Apart from alarms, which can be detrimental, there are a variety of sophisticated app devices for snoozing and napping. These apps claim to be able to stop waking you up during the wrong phase of your sleep cycle. Many people find these apps helpful. Some examples are: Napply and Power Nap Alarm for Android; pzizz and Nap App for iPhone. There are a huge number of options available.
There is one simple trick that works for many people without needing high-tech devices. Try drinking a cup of coffee just before napping. Caffeine takes a while to react in the body and so it won't act immediately to stop you going to sleep, but it will wake you up after a short nap. Coffee appears to help prevent the risk of sleep inertia and grogginess which is nappers curse. Similarly lying on your side, and not totally flat helps stop you falling into a deeper longer sleep.