There Are 4 Stages Of Your Sleep Cycle & This Is How To Wake Up During The Right One

Even if you've never formally looked into the four stages of sleep, you probably already know what they feel like: We lie down to go to sleep, start to drift off, maybe have one of those jerky twitches, then fall into light sleep, deeper sleep, and of course, REM sleep, where dreams occur. Each stage has a particular function, with one of them being the best to wake up during.

In Stage 1, you slowly begin to drift off. You might feel like you're falling at some point during this stage and suddenly jerking back awake. The official name for this reaction is hypnic myoclonia1, and it's totally normal (but stress and excess caffeine may make it more common). In this stage, your body and mind start "winding down," so to speak, traveling in and out of consciousness before you enter light sleep.

Stage 2 is the light sleep stage, and we spend about 50% of our sleeping hours in it. Your heart and breath rate begin to slow down as you settle into rest. Your body temperature also drops. No REM yet, but your brain will start producing "sleep spindles2," or rapid bursts of brain activity that regulate sleep.

Stage 3 is deep sleep (formerly Stage 3 and 4, which were combined), and it's the sleep stage involved in restoring your body. Deep sleep promotes muscle and tissue growth, along with cell repair. This stage is also sometimes known as delta sleep, as delta brain waves occur. If you wake up during deep sleep, you'll likely experience sleep inertia or grogginess.

Lastly, we have REM, or rapid eye movement sleep. This is this stage in which most dreams occur, memories are consolidated, and our brains recharge. Breathing and heart rate go up, the brain is active, and the body no longer moves (to prevent us from acting out our dreams).

The first REM cycle of the night usually lasts about 10 minutes, and it occurs 90 minutes after you fall asleep. As the night goes on, each REM stage will get longer, with the last one potentially reaching an hour in length. People average about four to five REM cycles a night. Interestingly, we spend less time in REM sleep the older we get. While babies can spend up to 50% of their sleep in this stage, adults average about 20 to 25% in REM3.

It's important to note that the stages don't occur in order. We go through Stage 1, 2, and 3, then back to 2, before entering REM sleep. This takes about 90 minutes. After REM sleep, we go back to Stage 2 again to repeat the cycle. So this leaves us with the question: Is there a stage that we should try to wake up during in the morning?

According to Girardin Jean-Louis, Ph.D., professor of population health and psychiatry at New York University, it is ideal to wake up after a full sleep cycle—though it's hard to train your body to do that. "If one comes to the end of a full night's sleep, one wakes up naturally—that's the ideal way to wake up," he says. "It is difficult to train oneself to wake up during any stage of sleep (since one is no longer aware of one's surroundings), unless conditioned with an alarm."

Rebecca Robbins, Ph.D., sleep researcher and co-author of Sleep for Success!, adds, "The most important thing to do before drawing attention to your wake-up time is to ensure you are spending enough time to get the sleep your brain and body need."

The overall consensus is that making enough time for deep, restorative sleep night after night is really the only way to naturally waking up during the optimal stage in your four-step sleep cycle. While we may not be able to fully control when we wake up, with good sleep hygiene, our body will do it properly for us.