Sleep Biology

While it may look as though nothing is happening when we sleep, our bodies are busy conducting maintenance and our brains are going through waves of activity as we lie there, largely unaware that any of this is happening. 

Sleep Cycles

Our sleep is broken by cycles which occur naturally as the night progresses, beginning with a period of light sleep where we’re still aware vaguely of what’s going on and are easily woken, gradually moving to a deeper sleep state which is harder to be woken from. During this sleep phase our heart rates are stable, and our breathing is steady. Our bodies are busy repairing muscle and other tissue, boosting our immunity, stimulating growth and development and providing energy for when we wake. Next, we head into a period of REM (or rapid eye movement) sleep. This is the sleep phase we all know which is recognisable by flickering eyes and twitching movements, and we dream. During this stage our brains are helping us to learn, shifting short-term memories to long-term and processing information we learned from the day before. From here we shift to a lighter phase of sleep as we reach the end of a full sleep cycle and drift into the next. Each full sleep cycle will last for around 90-120 minutes.

Children’s Sleep Cycles

In young children and babies sleep cycles differ from adults and change as they grow, and while they may follow a similar pattern to us, the amount of time they spend in each phase is different to us, and the length of their sleep cycle also differs. Babies spend around 50% of their sleep in REM sleep where their brains are busily working on development and learning, consolidating their cognitive and physical skills which they are constantly building on as they grow, compared with only around 25% in adults. 

We move through these cycles seamlessly most of the time, going from one to the next as, while we may wake lightly at the end of a cycle, we have learned to link our sleep cycles and roll over and go back to sleep. This skill helps us to achieve a full night’s sleep, giving our bodies the chance to heal and maintain our tissues, our immunity is improved, and our learning and memories are processed. Sleep is crucial for these processes to occur and helping our children to achieve this needs to be a priority so that they can grow and develop to their full potential.