Forcing an early wake-up time could harm your health, sleep doctors warn

With a new year underway, it might seem like a good idea to embrace a stricter morning routine of waking up early and getting a jump-start on the day — but a 6 a.m. alarm isn’t for everyone, experts say.

"Morning birds" fall asleep and reach deep sleep earlier, often waking up more alert, while "night owls" naturally sleep later and rely more on late-night and early-morning REM. Waking too early can leave night owls groggy and less mentally restored. 

"We need to move beyond the ‘early...