We’ve all been there: you’re in the middle of a beautiful dream. Maybe you steal. As you soar through the air, you encounter an eagle. The eagle looks at you, opens its beak and – BEEP! BEEP! BEEP!

Your alarm goes off. The dream is over, it’s time to get up.

Many people – children and adults – notice that when they wake up naturally, they feel more alert than if an alarm or another person, such as a parent, woke them up. Why then?

I am a neurologist which studies the brain, specifically what happens in the brain when you sleep. I also care for children and adults who don’t sleep well and want to sleep better. My research involves working with parents to help them teach good sleep habits to their children.

To understand how to sleep better and why waking up naturally from sleep helps you feel more alert, you need to start by understanding sleep cycles.

The sleep cycle

THE sleep ride a bike consists of four stages. One of them is REM, which stands for rapid eye movements. The other three are non-REM stages. When you fall asleep, you first enter a state of drowsiness called non-REM Stage 1.

This is followed by deeper phases of sleep, called non-REM phases 2 and 3. Each non-REM phase is deeper than the previous one. Then, about 90 minutes after you first fall asleep, you enter stage four, which is REM sleep. This is a lighter stage of sleep where you largely dream. After a few minutes, you return to non-REM sleep.

These cycles repeat throughout the night, with most people having four to six cycles of non-REM sleep alternating with REM sleep each night. As the night progresses, the cycles contain less non-REM sleep and more REM sleep. This is why it is important to get enough sleep so that the body can enough of both REM sleep and non-REM sleep.

REM sleep or non-REM sleep

How do researchers like me know when a person is in non-REM or REM sleep? In the sleep lab, we can tell by their brain waves, eye movements, and muscle tension, like at the chin. These are measured by placing sensors called electrodes on the scalp, around the eyes and on the chin.

These electrodes pick up brain activity, which varies from low amplitude (the height of the wave) and relatively fast waves to high amplitude (a higher wave) and relatively slow waves. When we are awake, the height of the waves is low and they move relatively quickly. In contrast, during sleep, the waves become higher and slower.

Non-REM stage 3 has the highest and slowest waves of all sleep stages. In REM sleep, brain waves are low in amplitude and relatively fast, and eye movements are also rapid. People need both non-REM and REM stages to have a healthy brain so they can learn and remember.

Wake up naturally

When you wake up alone in the morning, it’s usually at the end of whatever sleep phase you’re in. Think of it like getting off the train when it’s a stop at the station. But when an alarm or someone else wakes you up, it’s like jumping off the train between stops, which can be a jarring sensation. This is why it is good to wake up naturally as much as possible.

People can actually train their brains to wake up at a consistent time each day, providing a natural stopping point. Brains have a internal 24 hours clock this dictates when you start to feel sleepy and when you wake up. This is linked to our circadian rhythms.

You can adjust your circadian rhythm so you wake up naturally every morning.

Training the brain to wake up at a consistent time

First, it’s important to go to bed at a consistent time that allows you to get enough sleep. If you stay up too late doing homework or checking your phone, it can prevent you from getting enough sleep and leave you dependent on an alarm – or your parents – to wake you up.

Other things that can help you fall asleep at a healthy time include engaging in physical activity during the day and avoiding coffee, soda, or other caffeinated drinks or foods. Physical activity increases brain chemicals that make it easier to fall asleep, while caffeine does the opposite and keeps you awake.

Second, you must be aware of light in your environment. Light too late in the eveningincluding those from screens, can interfere with your brain’s production of chemical called melatonin which promotes sleep. But in the morning, when you wake up, you need to expose yourself to light.

Morning light helps you synchronize or align your circadian rhythms with the outside world and makes it easier to fall asleep at night. The easiest way to do this is to open your blinds or curtains in your bedroom. In winter, some people use light boxes to simulate sunlight, which helps them align their rhythms.

Benefits of a good night’s sleep

A good sleep routine involves both a consistent bedtime and wake-up time and getting enough, regular sleep. This usually means 9 to 11 hours for school-age children who are not yet adolescents and 8 to 10 hours for adolescents.

This will help you be at your best learn at school, improve your moodI help you maintain good health weight, and promote many other aspects of health.

Beth Ann Malow is a professor of neurology and pediatrics at Vanderbilt University. This article is republished from The conversation under a Creative Commons License. Read the original article.