August 2018

REM, Light, Deep: How Much of Each Sleep Phase Do I Need?

Getting the right amount of sleep is important because it’s linked to how you’ll function throughout the day. Crankiness, a short attention span and lethargy are all symptoms of not getting enough sleep. Learning about the sleep cycle can help you monitor the amount of rest you need to be getting, with REM (rapid eye movement) playing a big role. But what exactly is REM and how does each stage correspond to feeling refreshed after you wake up?

Understanding the sleep cycle

The sleep cycle can be broken down into five stages:

  • Stage 1
  • Stage 2
  • Stage 3
  • Stage 4
  • REM

The cycle represents the time it takes for someone to go through each stage. On average, the sleep cycle takes between 90 to 110 minutes, with each stage being between 5 to 15 minutes. Different events occur through every stage. The first two stages are considered to be light sleep, while stage three and four are known as deep sleep.

Stage 1

Stage 1 is the kind of shallow sleep that involves an awareness of your surroundings. This means you’ll be woken up easily, though the first stage is usually a quick transitional period.

Stage 2

This is the stage that many people believe to be light sleep. It’s important to remember that this stage isn’t shallow or any less meaningful. Light sleep forms a significant part of the cycle, with the body regulating itself.  Physical changes include a lowered heart rate and slowed breathing.

Stage 3

Stage 3 is the beginning of deep sleep and you become less aware of outside stimuli. The brain emits delta waves and it becomes difficult to be woken from this state. The body generates growth hormone that restores the immune system and carries out maintenance.

Stage 4

In Stage 4, the mind is completely offline and the muscles are relaxed. There are no dreams in deep sleep and the body continues to repair itself. Anyone who is woken from this stage may feel disorientated for several minutes.


REM sleep is when the mind is most active and the body is inactive. Emotions are processed and this is when you’re likely to dream. Body inactivity is so great that you become physically paralysed. Some scientists believe that the body reacts like this to protect us against injury in case we try to act out our dreams.

During the REM stage, eyes move rapidly, blood pressure rises and heart rate increases. A person may wake up after REM.

Are there different cycles?

During sleep, you don’t hit each stage once a night. The cycle is made up of going through the stages multiple times. A cycle usually progresses through light to deep sleep, then reverses back from deep to light. The cycle ends with REM and then starts again with light sleep.

How do you measure sleep by the stages?

With each stage being broken down, it’s estimated that light sleep takes up about 50% of the night. Deep sleep can take up to 10% to 25%, though this depends on age. Getting deep sleep is key to having a refreshing rest because this is when the body is healing itself.

REM is estimated to take up between 20% to 25% of the night. If you don’t get enough REM sleep then it may lead to grogginess and memory problems.

The averages will vary depending on how old you are. Resting in a comfortable bed is one of the best ways to make sure you have a good night’s sleep. Our range of mattresses are designed to help support your body and we cater for people of all ages.




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