At least, not always. When you rise before dawn to finish a last-minute task, you may be more likely to experience microsleeps—temporary moments of nodding off that can last up to 30 seconds. "Your body follows its own circadian rhythms and wants to keep sleeping," says
Michael Twery, PhD, a sleep expert at the National Institutes of Health. Try to complete your work before you turn in (even if it's past your normal bedtime). And if possible, Twery advises, plan ahead for the lost sleep with a nap during the day.
—Ashley Williams
Signs your body is too tired to go on (even if you're not)
