Drifting into the Four Stages of Sleep

Sleep is not a simple matter of just shutting off mind and body. As it turns out, we are actually very busy during this daily function that requires the shutting off of our conscious minds. Healthy sleep is experienced as cycles of 4 stages of brain and bodily activity. Over the course of the night, a person typically goes through four to six sleep cycles. On average, each cycle lasts about 90 minutes.

Stage 1 is the “dozing off” stage lasting just one to five minutes during which body and brain activities start to slow with brief twitches. This is the period where your consciousness just starts to drift and you can easily be awakened.

During stage 2, your body temperature drops and your muscles relax. Your breathing and heart rate also start to slow down. And while your brain activity slows down, there are short bursts of activity which actually help resist being woken up by external stimuli by masking them.

Deep restorative sleep occurs in stage 3 where brain waves slow down to what are known as delta waves. It is harder to wake someone up during this stage and if awakened, you will feel groggy and disorientated. Muscle tone, pulse, and breathing rate are at their lowest. Increased blood flow to muscles and the release of growth hormones allow for tissue repair and growth, boost the immune system and process toxins and wastes out of the body. During this deeply restorative stage, hormones that suppress appetite and helps control unnecessary over-eating are released.

Stage 4 is REM sleep known for the period of sleep where the most vivid dreams are experienced. Brain activity picks up, with heightened desynchronized brain waves, almost similar to being awake. At the same time, the body experiences a temporary paralysis of the muscles, with two exceptions: the eyes and the muscles that control breathing. While Stage 3 is essential for restoring the body while the mind rests in delta state, stage 4 is essential for developing cognitive function like memory, learning and creativity and supports sharp and alert daytime function.

Bearing in mind that stages 3 and 4 are the times when both body and mind are healed and restored, we should value natural, deep sleep as a vital part of life and health. In my next blog, I shall look at how at the power of our subconscious mind and the rules we can use to govern this powerful engine.