Last updated: August 15, 2026 · 7 min read You've read about sleep inertia — that foggy, heavy feeling that clings to you after waking up. But here's the thing: avoiding grogginess isn't just about when you wake up. It's about when you wake up in relation to your body's natural sleep cycles.

Last updated: August 15, 2026 · 6 min read Ever wake up from a nap feeling more tired than before? Learn what sleep inertia is, why it happens, and science-backed ways to beat the grogginess so you can wake up refreshed every time.