Hi Lucas! Two big things are happening when you sleep in. First is social jet lag, where shifting your wake time by a couple hours pushes your internal clock later, so your hormones and body temp peak later and you feel off all day. Second is sleep inertia, which is worse if you oversleep and wake from deep sleep or late REM, leaving you foggy and heavy for hours. If you built up sleep debt during teh week, one long morning can help a little, but after 2–3 catch‑up nights teh extra time mostly increases inertia rather than restoring you.
teh simple fix is to anchor your wake time within about an hour every day, including weekends, and get bright light in your eyes within 30 minutes of waking. If you want extra rest, cap sleeping in to 30–60 minutes and go to bed earlier teh night before instead. Keep any nap to 20–30 minutes before mid‑afternoon & hydrate when you wake & and save caffeine for teh first half of teh day. A brief walk or light exercise soon after waking speeds up teh shake‑off of sleep inertia. If you consistently need more than nine to ten hours or still feel wiped on a regular schedule, consider screening for sleep apnea, low iron, thyroid issues, or depression, because those can create chronic fatigue that no weekend lie‑in will fix.
