Sleep
Sleep is a necessity, not a luxury if you want to feel your best, stay healthy and perform up to your maximum potential. The power of sleep cannot be emphasized enough as the quality of your sleep directly affects the quality of your mental alertness, productivity, creativity, emotional balance, contentment, physical vitality and even your weight. Apart from your body resting and restoring its energy levels during sleep, your body also progresses cyclically from the first to the fourth stages of non-REM through to REM sleep (Rapid Eye Movement).
In stage one sleep or the transition period, you drift in and out of sleep; your eyes move slowly, your muscle activity slows down, and you are awakened easily. This stage lasts for about 5-10 minutes. Stage two, also known as light sleep is where you actually sleep, your eye movements stop, your heart rate slows, and your body temperature drops. This stage lasts about 20-25 minutes. In stage three or deep sleep, you are not easily awakened. If you are roused, you feel dazed, confused and take time to come around. Stage three is the transitional period between light sleep and extremely deep sleep. Stage four is the deepest stage of sleep where your brain waves are extremely slow; your blood flow is directed away from your brain and towards your muscles, restoring your physical energy and this lasts for about 30 minutes.
REM sleep or dream sleep is characterized by extensive physiological changes where your eyes move rapidly, your blood pressure, heart rate and respiration rate increases, the voluntary muscles of your arms and legs are paralyzed (relaxed) and your brain activity increases. You enter REM sleep about 70-90 minutes after falling asleep. You progress through stages one to four of sleep and after stage four, you repeat stage three and then stage two before entering REM stage. Your body usually returns to stage two sleep once REM sleep is over and a complete sleep cycle takes an average of 90-110 minutes. The quality of your sleep changes with transition from one sleep stage into another with corresponding changes in your bodily function. The length of time you sleep in each stage is important though deep sleep and dream sleep are most vital.
During deep sleep, your body repairs its muscles and tissues, stimulates growth and development, improves your resistance and builds up energy for the next day. REM sleep renews the mind and helps in learning and memory. Your brain also consolidates and processes the information you learned during the day and refills its supply of neurons such as serotonin and dopamine (feel-good chemicals) that boost your mood during the day. Lack of sleep affects your judgment, coordination, and reaction times therefore maximize your quality of sleep and get good restorative sleep as well as mind and mood-boosting REM sleep every night.
