The answer to this question might surprise you with its simplicity — and its nuance. The best position to sleep in is whatever position allows you to complete 4–6 REM cycles and accumulate 1–2 hours of deep sleep per night. That's the real metric. Not whether you're on your back, your side, or your stomach — but whether your body is getting the restorative rest it actually needs. That said, position does matter. Because the position that gets you there might also be quietly working against you in other ways. Here's what you need to know.

If you've ever searched this question online, you've probably found a lot of confident, cookie-cutter answers. The truth is, there isn't one — and anyone who tells you otherwise may not be seeing the full picture.