“I find myself waking up fully energized”

Is sleeping 8 hours a day a BRULE? Ever since meditating using 6 Phase and The M Word, I find myself waking up fully energized after 5-6 hours of sleep.I usually wake up around 4:55am-5:30am and force myself to fall back asleep because I'm under the impression that we need 8 hours to fully energized.... I find when I do force myself to snooze for those two extra hours I wake up feeling more tired.