Sleep expert reveals why a light snooze can be just as important for your health as deep sleep

Light sleep is critical to our health even though we might not hear it all the time, and just a short nap could increase your cognitive performance.

While many people will be familiar with the reported benefits of deep or REM (rapid eye movement) sleep, the benefits of lighter sleep are less well known.

Sleep is divided into five stages – wake, N1, N2, N3, and REM – and each stage is deeper than the last.

Light sleep can refer to stages N1, N2, or both, and makes up to around half of our time sleeping.

Dr Chester Wu, MD, Medical Reviewer at Rise Science explains the benefits of light sleep below.

REM (rapid eye movement) sleep is credited with restoring energy and aiding emotional processing, but the benefits of light sleep are less well known

Just a quick nap can help improve your alertness and cognitive performance according to a sleep expert

What happens in light sleep?

Dr Wu explained: ‘Light sleep serves as a transition between wakefulness and the deeper stages of sleep. 

‘It allows the body and mind to slow down and prepare for deep sleep and REM sleep, which are crucial for physical and mental restoration.’

During light sleep, your heart rate, blood pressure, and body temperature all decrease, allowing your body to conserve energy and direct more resources towards restoration and recovery. 

Alongside this broad powering down, there are also flickers of brain activity called ‘sleep spindles’ which are not fully understood, but scientists believe they may play a role in forming and consolidating memory.

What are the benefits of light sleep?

As mentioned above, REM sleep is largely seen as the most beneficial stage of sleep.

Without detracting from this Dr Wu explained that light sleep still has significant benefits of its own.

‘Light sleep is critical for health and wellbeing,’ he said.

‘While REM sleep is often linked to memory consolidation, recent studies suggest that light sleep also plays a role in this process, especially in the consolidation of motor memory – the memory of how to do physical tasks.’ 

Additionally, he said that research indicates ‘short periods of light sleep, such as power naps, can increase alertness and cognitive performance.’

Dr Wu also pointed out that instead of ‘light sleep’ Apple actually use the term ‘core sleep’ in their sleep monitoring. 

How much light sleep do you need?

Dr Wu explained that the amount of light sleep we need is unique from person-to-person, and day-to-day

He said: ‘Healthy sleep will include all stages of sleep based on your needs – our brains optimize nightly based on factors like our health and whether we’re sleep deprived. 

‘To get enough of any stage of sleep, the best thing we can do is to prioritize getting enough naturalistic sleep through healthy sleep hygiene habits, rather than focusing solely on increasing or decreasing time spent in a particular sleep stage.’