The first rule of afternoon napping is an alarm clock: If you don't want to feel groggy afterwards, you need to limit the duration. Here are seven questions and answers about the most important break of the day. Berlin (dpa) - You might take one after your early shift, during your lunch break while working from home, or at the weekend. Many people swear by afternoon naps. What are their benefits and how can you get the most out of daytime snoozes? Two experts answer some pertinent questions: 1. Is taking afternoon naps healthy? "Yes, but only if they're power naps," says Markus Specht, who heads a centre for sleep medicine in Germany. In other words, short naps of about 10 to 30 minutes - also called catnaps - that end before you enter deep sleep. Studies in Mediterranean countries, where siestas are historically common, have shown that people there are less prone to cardiovascular diseases, obesity and strokes than non-siesta cultures are. "What's more, studies of people in the US showed their risk for these conditions decreased when they started taking afternoon naps and hadn't previously," says Dr Simone Koch, a physician, hormone expert and biohacker who investigates how healthier behaviours can optimize natural bodily processes. 2. When's the best time for a power nap? Ideally, you should lie down and close your eyes for 15 to 20 minutes after lunch, between 1 and 2 pm, advises Specht. "That's when your body experiences a natural energy slump and slips more easily into rest mode," he says. It's important to keep the nap short so as not to sink into deep sleep, so "be sure to set an alarm!" 3. What happens in your brain when you power-nap? When you close your eyes and simply wait for what comes next, your brain goes into a meditative state. Your brain waves are in what's known as an alpha rhythm, and your consciousness is idle. "You can imagine it to be a bit like a screen saver for your mind that tidies up in the background and then restarts the system," Specht says. "That's why you feel so refreshed after a successful power nap." 4. Why do you sometimes feel groggy after an afternoon nap? Usually because you let what should have been a power nap last too long, allowing your body to enter the deep sleep phase. "Your brain's then ready to sleep for six more hours," says Specht. "If you're abruptly awakened, you feel downright disoriented." On top of that, you don't become really alert again until evening, and therefore have trouble falling asleep at bedtime. Koch adds: "People with very low blood pressure often need quite a long time to get into gear again. So for them, even power naps may be disadvantageous." And they're hardly alone, as not everyone's made for afternoon naps. If they throw your day out of kilter by making you sluggish instead of refreshed, it's best to avoid them. 5. Can afternoon naps be counterproductive? Yes, as noted above. If you regularly end up falling fast asleep, you'll disrupt your natural sleep-wake cycle. Yielding too early in the day to the build-up of "sleep pressure" - ie. an increase in the concentration of various neurochemicals and hormones in the brain that allow your body to sleep - makes it harder to fall asleep at night. And having trouble sleeping at night can be extremely stressful for both mind and body. It can set a vicious circle in motion, leading to a bad case of insomnia requiring medical treatment. Babies, the ill and elderly are an exception though, according to Specht, noting that "at an advanced age the body produces less melatonin [known as the "sleep hormone"] at night, which reduces nighttime sleep, so napping during the day can be very restorative." 6. Can an afternoon nap make up for a sleepless night? If you hardly slept a wink, let alone 40, after a wild party, due to heartbreak, intrusive thoughts or whatever, it's best to stay awake until evening. Similar advice is given to head off jet lag. While a power nap can work wonders in these cases too, Specht says, you risk lying wide awake in bed when nighttime comes. 7. What are the immediate, and long-term, effects of power-napping? A proper power nap has effects that are felt at once, says Koch. "As soon as you get up again, you're more alert, receptive and able to concentrate." If you make them a lifelong practice, you can reap their benefits into old age. There's even evidence that regular napping can significantly delay the onset of age-related diseases as well as frailty. "I'm personally convinced that power naps not only make you physically and mentally fitter, but also strengthen your mental health in the long term," Specht says. In short, regular power-napping can make you more alert, less stressed and better able to meet the day's challenges with equanimity. And every power nap helps, even though for many people they're only possible at the weekend. The following information is not intended for publication dpa/tmn osf yyzz a3 bzl sw ob (The article has been published through a syndicated feed. Except for the headline, the content has been published verbatim. Liability lies with original publisher.)
