What Happens To Our Bodies When Sleeping?

22nd August 2022

When you sleep, your body is still working and changing. The quality of rest you get is essential to your overall health, because it’s the period in which your mind has time to slow down and process the recovery of muscles, tendons and cells. These are fundamental processes, but what does your body actually do when you’re getting forty winks?

Sleep cycles

During a regular sleep cycle, the body progresses through four to five sleep cycles, each of which is made up of four individual sleep stages. These include rapid eye movement (REM) and non-REM sleep. What happens during these stages differs significantly. The first three stages of sleep are non-REM activity. Stage one is when you’re first dozing off into sleep, so this is the shortest stage, while stage two is when your body and mind slow down as you fall into sleep – during these two stages, it’s easiest to be woken up.

In stage three, which is also referred to as deep sleep, your body goes into recovery mode and slows even further. Your brain activity slows down and will start to show patterns of pulses of activity, which experts believe help to avoid the body being woken while the body is recovering.

Finally, stage four is REM sleep. During this stage, your brain activity shoots back up to similar levels as it would reach if you were awake, and it’s when you’re likely to experience the most intense, vivid dreams. Each sleep cycle lasts between 70 and 120 minutes, but most of your sleep at night will be non-REM. REM sleep happens primarily in the latter half of your sleep.

What happens to your brain and body?

Breathing and heart rate: Your breathing will slow during non-REM sleep and be at its slowest in stage three. Then when you’re in REM sleep, it will quicken and being irregular. Similarly, your heart rate will slow in stage one, be at its slowest in stage three, and then quicken to almost the same rate as when you’re awake during REM sleep.

Muscles: Your muscles relax during non-REM sleep and your energy expenditure will drop, then they’ll become paralysed during REM sleep which is to stop your body from acting out your more vivid dreams.

Brain activity: Non-REM sleep facilitates your brain function during waking hours, while REM sleep benefits cognitive abilities including memory consolidation.

Hormones: Sleep regulates the body’s internal clock and hormone production, including cortisol for your stress response system; leptin and ghrelin, which control your appetite; and melatonin, which promotes sleep.

How to improve your sleep quality

Over time, poor sleep can cause hormone imbalances, mental fog, irritability and even worsen mental health problems such as anxiety and depression. Focusing on going to sleep and waking up at similar times each night can help get your body in a rhythm, and making sure your bedroom is comfortable and cool can also encourage better sleep. CBD products, such as the OTO CBD sleep range, can also help to balance your natural sleep rhythm by helping you relax.

Sleep is such a vital component of our wellbeing routine, and yet so many of us don’t prioritise it or give it the attention it deserves. Focusing on getting the right amount, and the best quality, of sleep can make all the difference to our mental and physical health.