Why do people sometimes wake up just before their alarm goes off?

It's common to wake up naturally just before your alarm goes off, even though you've set it, but this isn't a coincidence. A research team led by Yakut Fatima, professor of sleep health at the University of Sunshine Coast in Australia, Alexandra Metz, senior lecturer in psychology, and Daniel Wilson, research fellow and sleep scientist, explains why people wake up just before their alarm goes off by looking at the mechanisms of our internal clocks.

Why do we wake up shortly before our alarm goes off? It's not by chance
https://theconversation.com/why-do-we-wake-up-shortly-before-our-alarm-goes-off-its-not-by-chance-268992

First, the human brain contains a collection of nerve cells called the suprachiasmatic nucleus , also known as the 'body's master clock,' which regulates the rhythms of various physiological functions, such as sleep, wakefulness, body temperature, hunger, and digestion. This suprachiasmatic nucleus is thought to regulate the body's internal state based on a 24-hour circadian rhythm , determining 'when to sleep and when to wake up.'

Circadian rhythms vary from person to person, with some people being 'morning types' who are active early in the morning and others being 'night types' who tend to stay awake late into the night. However, the research team explains that 'neither is abnormal, but rather is due to the characteristics of each individual's internal clock.'

The body's internal clock is not fixed at birth, but is learned through daily habits. The more regular your sleep and wake-up times, meals, and exercise, the more your internal clock will remember those rhythms and predict your next actions, resulting in the secretion of necessary hormones at the appropriate times.

Additionally, a hormone called cortisol is deeply involved in waking up in the morning. The research team states that when we wake up, a phenomenon called the 'cortisol awakening response' occurs, and cortisol secretion increases significantly. This is thought to be a response that switches the body into an active state and prepares for the start of the day.

If you wake up at roughly the same time every day and get plenty of natural light in the morning, your body clock will learn exactly when to wake up, and your body will start preparing for it long before your alarm goes off. Specifically, your body temperature will rise, your production of melatonin, a hormone that promotes sleepiness, will decrease, and your production of cortisol will gradually increase.

Therefore, by the time your alarm goes off, your body has already begun to transition into a waking state, the research team explains, likening it to a ' hormonal wake-up call .' Waking up just before your alarm and feeling refreshed is a sign that your circadian rhythm is in good order, meaning your body clock accurately predicts your daily patterns and smoothly transitions from sleep to wakefulness. On the other hand, if you wake up early but feel very sleepy or sluggish, this could be a sign of poor sleep quality, which doesn't necessarily mean your body's rhythm is fully regulated.

Maintaining consistent bedtimes and wake-up times is important for stabilizing your body clock. When your lifestyle is in sync with the rhythms of the natural environment, such as daytime brightness and temperature changes, it's easier to fall asleep and wake up smoothly. Conversely, if you continue to live a lifestyle in which your sleep time varies greatly from day to day, your body rhythm becomes disrupted, which can lead to daytime sleepiness, decreased concentration, and impaired thinking performance. With an irregular lifestyle, your body clock cannot predict when to wake up, so you end up relying on an alarm clock, which can wake you up in a deep sleep stage, leaving you feeling very sleepy, a condition known as ' sleep inertia .'

Stress and anxiety are also factors that affect sleep. The research team points out that stress and anxiety increase the secretion of cortisol, which can cause shallow sleep at night and early morning awakenings. It also seems that having exciting plans or important events coming up can help keep the brain in a high state of alertness, which can cause you to wake up earlier than planned.

Before the Industrial Revolution, people slept in accordance with natural environmental changes such as the sun and moon. However, in modern times, artificial lighting and irregular lifestyles make it difficult to wake up naturally without an alarm. However, if you wake up naturally before your alarm goes off, it is a sign that you are well rested and your body clock is functioning properly, according to the research team.

The research team recommends getting 7 to 8 hours of sleep, including on weekends; keeping your bedtime and wake-up times as consistent as possible; avoiding caffeine, alcohol, and heavy meals before bed; keeping your bedroom dark and avoiding screen time before bed; and getting plenty of natural light in the morning.