For the latter part of sleep is moreimportant.

For lack of space, I cannot explain here the ideal sleep architecture. But inbrief, sleep is composed of two stages: REM ( Rapid Eye Movement ) and non-REM. The former helps in mental consolidation while the latter helps inphysical repair and rebuilding. During the night, you alternate between REMand non-REM stages 4-5 times.The earlier part of sleep is mostly non-REM. During that period, yourpituitary gland releases growth hormones that repair your body. The latterpart of sleep is more and more REM type For you to be mentally alert during the day, the latter part of sleep is moreimportant. No wonder when you wake up with an alarm clock after 5-6 hoursof sleep, you are mentally irritable throughout the day (lack of REM sleep).And if you have slept for less than 5 hours, your body is in a completephysical mess ( lack of non-REM sleep ), you are tired throughout the day,moving like a zombie and your immunity is way down ( I’ve been there, donethat )