(Time) For as long as Seemay Chou can remember, she has gone to bed at midnight and woken around 4:30 a.m. Chou long assumed that meant she was a bad sleeper. Not that she felt bad. In fact, sleeping just four hours a night left her feeling full of energy and with free time to get more done at her job leading a research lab that studies bacteria. “It feels really good for me to sleep four hours,” she says. “When I’m in that rhythm, that’s when I feel my best.”
Still, in an effort to match the slumber schedules of the rest of the world, she would sometimes drug herself–with melatonin, alcohol or marijuana edibles–into getting more sleep. It backfired. “If I sleep seven or eight hours, I feel way worse,” she says. “Hung over, almost.”
Although the federal government recommends that Americans sleep seven or more hours per night for optimal health and functioning, new research is challenging the assumption that sleep is a one-size-fits-all phenomenon. Scientists have found that our internal body clocks vary so greatly that they could form the next frontiers of personalized medicine. By listening more closely to the ticking of our internal clocks, researchers expect to uncover novel ways to help everybody get more out of their sleeping and waking lives.