Sleep is a vital reversible state of reduced consciousness that will take up one-third of our lives. Taking part in good sleep is a component of a healthy thriving life. Before the invention of light bulbs people would sleep about 10 hours a night, and today American will range about 6-7 hours of sleep on a weekday and 7.5-8 hours of sleep on the weekends.
What is sleep really doing for us? Is it always restful? Although, our eyes may be closed, our breathing slow and deep, and our muscles relaxed, our brain, however, is very active.
There are 4 stages of non rapid eye movements (NREM) sleep and REM sleep. In the first our theta waves are increased which are associated with the intention to move rather than with feedback produced by movement. We also have less alpha waves which is believed to represent the activity if the visual cortex a lazy state. This is the stage where you may experience the hypnic jerk (an involuntary contraction of your muscles) because you’re in the transitional stage between wakefulness and sleep.
In the second, this is the onset of “real sleep” we become disengaged from the surroundings. Breathing and heart rate are regular, body temperature drops and you spend about 50% of the night in this stage.
In the third/fourth, slow wave sleep, this is the deepest and most restorative sleep (delta waves) this is usually the highest difficulty waking. Blood pressure drops, breathing becomes slower, and muscles relax. Tissue growth and repair occurs, especially in the liver. Growth hormone is also release which is essential for growth and development.
REM (25% of the night): this will usually occur about the first 90 minutes after falling asleep and reoccurs about every 90 minutes after and laster longer and longer. Eyes dart back and forth, this indicates that the brain is active and dreams are occurring. This stage of sleep provides energy to brain and body supports daytime performance.
Sleep has so many benefits, maintains circadian rhythms, processing of learning, rest of conscious mind, recharging neurotransmitters, bodily rest, and mostly overall health!