Sleeping well for an entire night, without waking up once, seems to be a surprisingly rare thing, but it’s actually what’s required if you’re to be entirely productive – without feeling tired – the next day.

Many people think that simply going to bed at the right time guarantees them a good night’s sleep, only to then wake up – more often than not – between 3:00am and 5:00am. Sometimes this can cause problems, particularly when someone finds it difficult to return to sleep.

The fact that most people wake up during this window isn’t coincidence, however, nor is down to bad luck. It turns out, there’s a significance to the trend …

The hours between 3:00am and 5:00am are sometimes referred to as the hour of the wolf, after Swedish director Ingmar Bergman’s psychological horror^[film of the same name.

”The hour between night and dawn … when most people die, sleep is deepest, nightmares are most real. It is the hour when the sleepless are haunted by their worst anguish, when ghosts and demons are most powerful. The hour of the wolf is also the hour when most babies are born,” Bergman explained.

According to Professor Birgitta Steene, the title is derived from Swedish folklore, wherein the “hour of the wolf” signifies the timeframe between 3:00am and 5:00am.

This period is believed to be associated with a higher occurrence of both deaths and births. It’s also precisely that time when the body often slips into its deepest rest, which is why the body’s functions can be so affected by it.

In folk traditions, the witching hour, also known as the devil’s hour, is a nocturnal period linked to supernatural occurrences. It is believed that during this time, witches, demons, and ghosts are thought to manifest and wield their greatest influence.

The hour of the wolf

For those who are able to sleep as normal, the hour of the wolf represents the period wherein sleep is at its deepest. For those who wake up, however, it supposedly represents the time when feelings of anxiety are at their most potent.

The body’s circadian rhythm (the 24 hour cycle of physiological processes) tends to follow the sun’s rise and fall, meaning that things such as body temperature, blood pressure and metabolism go down during the night.

At around 4:00am they are at their lowest, since this is when the body has entered its natural rest stage. If you suffer from anxiety, however, it’s during this period when feelings can be exacerbated, hence why you find yourself waking up.