Sleep Research
Stage 1 – Lasts for approximately 20 minutes and is the stage where the heart rate slows and the body temperature begins to cool down. The brain activity during this time shows up in “spindles”, which are essentially tightly packed brain wave patterns. These spindles have been linked to muscle memory and internalizing movements learned during the day.
Stages 2 and 3 – Stage 2 is the transition from light to deep sleep, and Stage 3 is complete deep sleep where the body produces very slow waves called Delta Waves. This stage of sleep is often called Slow Wave Sleep (SWS). During this stage HGH is released, blood rushes from the brain to the muscles to initiate recovery and re-energize your body. Additionally, elements of the parasympathetic nervous system are triggered while the sympathetic nervous system is suppressed. All of this supports immune function and normal glucose metabolism during the day.
Stage 4 – Otherwise known as REM sleep, this is the stage where we dream. Our arms and legs are paralyzed, and this is the only stage of sleep where the body doesn’t actually move. This stage of sleep is associated with learning and memory retention, where the hippocampus transfers and filters the day’s information to the neo-cortex, kind of like a computer uploading information and clearing it’s RAM onto a hard drive.
During the first few cycles deep sleep periods are longer and REM periods are shorter, but after the 4th cycle the REM periods become much longer and the deep sleep phases much shorter.
Important benefits of Deep Sleep (Slow Wave Sleep)
• Maximum natural production of HGH – this is a hormone that the body naturally produces, and it is critical to your bodies ability to recover from hard work during the day. HGH keeps you looking and feeling young, and our bodies are programmed to secrete HGH in high doses during sleep. However, the body can only do this if it gets adequate amounts of deep sleep. While it is true that most of the HGH released during the night is released in the first few sleep cycles, research has shown that sleep deprivation can throw this off and eliminate the HGH bursts we get in the first few cycles of sleep.
• Suppression of Cortisol production – High levels of cortisol in the night create insulin resistance in the morning, and thus it is linked to coronary artery disease, stroke, type II diabetes, memory loss and cognitive impairment.
• Suppression of sympathetic nervous system in favor of sympathetic nervous system – the sympathetic nervous system is what is activated under stress, whereas the parasympathetic nervous system is what the body activates to recover and recuperate.
• Release of Prolactin, which has been shown to have anti-inflammatory properties and therefore may be important for joint recovery.
Important Benefits of REM Sleep and Stage 1 Sleep
• Spindles are critical to the brains ability to transfer learned muscle movements to permanent memory.
• The period where the Hippocampus transfers information to the neo-cortex, allowing us to recall information, motor skills, and other important information when we wake up and far into the future. Without enough REM sleep we can’t remember and internalize important mental skills, such as learning a new language or taking in new information for your job. In a competitive world where being on top of your mental game is crucial to your success in the work place, we all need enough REM sleep to keep our mental edge and not waste all our hard work during the day.
• Insufficient REM sleep has a negative impact on the brain as a whole and causes it to function differently, causing it to not function properly. As a consequence, the Hippocampus works less and other parts of the brain, like the Amygdala, work more. Since the Amygdala is associated with rage and aggression, sleep deprived people are often more irritable and moody. Since a positive attitude is so important functioning on the job, we simply can’t afford lapses that will cause us to lose our positive edge.
