Sleep is essential to overall health and wellbeing, performing numerous vital biological processes from muscle repair and growth, memory formation and immune system function.
Sleep has long been known to play an essential role in our mental and emotional wellbeing; those who don’t get enough restful slumber may be at greater risk for depression and anxiety.
Inactivity theory was one of the earliest theories on sleep and postulates that inactivity during night was an adaptive strategy developed for animal survival purposes; staying away from danger at times when animals would otherwise be most exposed was key in this strategy’s implementation.
Animals able to lie still for prolonged periods benefited greatly from being able to doze off, as this allowed them to avoid predators, prevent accidents during night activities and remain safe from hazards that other mobile creatures might present. Over time, this strategy grew into what we now recognize as sleep.
The Energy Restoration Theory can also explain why sleep is vital to our health. When asleep, metabolism slows (up to 10% in humans and more in other species), providing you with extra energy when awake.
Energy Conservation Theory
Sleep is essential to overall health and well-being. It helps the body recover from physical exertion, repair muscle fibers, build immunity and perform other necessary processes that contribute to keeping you in good shape.
Unfortunately, not everyone gets enough sleep; estimates show that as many as 35% of adults do not get the recommended amount.
Problematic stress increases people’s risk for serious illnesses and injuries, hinders their focus and decision-making abilities, affecting quality of life significantly.
Energy conservation theory holds that our ancestors developed sleep as a strategy for conserving energy when hunting food for sustenance. It makes perfect sense, since without enough energy they would become vulnerable and likely die without being able to hunt or move as freely.
Brain Plasticity Theory
Neurons in our brain have the ability to adapt over time through neuroplasticity – this occurs as a result of learning and experience.
Early childhood marks the peak of brain plasticity due to rapid brain development during these initial years of life.
Research has demonstrated that this change in brain structure results from neural networks reorganizing themselves to accommodate new experiences, also known as synaptic pruning – strengthening certain connections while diminishing others.
Retraining of movements, using speech therapy and healing damaged areas within the brain are all strategies used to recover from brain injury and restore functionality after injury. These may include the retraining of movements, speech therapy or even the repair of damaged regions within it.
Circadian Rhythm Theory
Most living things possess an internal clock called a circadian rhythm, which regulates essential functions such as memory consolidation, body healing and metabolism. Light exposure influences this pattern to keep our bodies functioning at optimal temperatures with hormone release, digestion and other related processes occurring daily.
Circadian rhythms are in tune with the 24-hour light/dark cycle via entrainment, which also serves to regulate them via the suprachiasmatic nucleus (SCN), which receives signals from your eyes telling it when to be active or sleepy.
The SCN contains clock genes that send messages to regulate biological rhythms across an organism, from individual cells to whole organs. If these clocks become out-of-whack, this could have detrimental effects on health conditions like cancer and immune disorders.