“You can train yourself to need less sleep.”
Strong confidence against training away sleep need. Controlled experiments show impaired performance despite partial adaptation. They do not imply that every person needs exactly the same sleep duration.
Feeling used to short sleep does not mean you have trained away your sleep need. Controlled restriction studies found attention and reaction-time impairment that persisted or worsened, sometimes without matching changes in reported alertness.
Sleep health is about more than one trick or number. Duration, timing, regularity and how you function during the day all matter.
Safety note: Feeling alert is not a reliable guarantee of safe driving after short sleep.
Talk to a healthcare professional if: Seek assessment for persistent excessive sleepiness, snoring with breathing pauses or insomnia.
You can get used to feeling tired, but you cannot train away your biological need for sleep.
Protect enough sleep instead of trying to become someone who can thrive on chronically short nights.
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Protect your 7-9 hours like you'd protect a workout - it's foundational, not optional. If you think you're the exception who needs less, you probably aren't.