The afternoon nap around here was never defended - it was hidden. Someone apologises that they „just lay down for a bit”, someone says they „closed their eyes for two minutes”, and everyone knows they slept an hour and a half and got up worse than they lay down. That „worse than they lay down” is exactly the part science explains, and the explanation is simpler than you would expect.

Neurologist and sleep medicine specialist Eduard Estivill has drawn up a ten-point guide to the afternoon nap, and his first rule is a number: between ten and twenty minutes. Not a minute more. „If you sleep longer, you enter deep sleep. Then there is no nap - there is a hangover”, he says.

That is the whole secret. It is not about how tired you are, but about which phase you are in when you wake. Coming out of deep sleep signals to the body that the night has just begun, and it then spends half an hour working out it has been tricked. That is why some people get up from a nap fresher, and others get up as if they had been beaten.

The clock matters as much as the length

The natural window is between one and three in the afternoon. That is not a Spanish habit but chronobiology - the body has a small dip in that period anyway. Sleeping later than that reduces sleep pressure in the evening, and then the same person who slept at six in the afternoon wonders why they are staring at the ceiling until midnight.

There is also something that lets off the hook anyone who „cannot fall asleep when they should”: you do not have to fall asleep at all. Closed eyes, fewer stimuli, a still position - the body takes its share even without formally falling asleep. You do not need a dark room, silence and a particular duvet. That is good news for anyone who has been treating an afternoon rest as a project.

Coffee before the nap, not after

The most counterintuitive advice is also the most usable. Caffeine starts working after around twenty minutes. If you drink it right before a short nap, you wake up exactly as it kicks in - rest and alertness in one package. Estivill additionally recommends five minutes of strong light, natural or artificial, and a ten-minute walk afterwards.

And one number that is devastating in its ordinariness: according to research by a hotel chain, 86 percent of Spaniards who nap exceed the recommended length, and more than half fall asleep spontaneously, without any plan. So almost everyone does the very thing they later complain about.

Estivill recommends napping at least three times a week, not every day. And he sets one limit that is important not to skip over: it is not a repair for a badly slept night. „If you sleep badly at night, a nap does not repair the damage.” Around here the afternoon nap is often defended as tradition. The problem is that the tradition lasts an hour and a half, while science gives twenty minutes - and those twenty minutes are the only ones that actually work.