Sleep quality is just as important as sleep quantity. REM (rapid eye movement) sleep is critical for memory consolidation and moods the following day. Every 90 minutes, you enter into REM sleep. If you get less than 4-6 hours of sleep, then you may lose a couple of REM sleep cycles…but at a cost to you and others who are depending on you to be at your best.
Sleep Tip #234: Sleep more than 6 hours to enhance sleep quality.