Every sleep-deprived new mother is told to nap when her baby naps. Preschoolers take naps during the day as well. Perhaps you love a good nap, too, because, come on, who doesn’t?

But here’s the (sad) rub: if you take a nap during the day, you’ll be less sleepy at night. If you’re less sleepy at night, it will be harder to fall asleep. If you can’t fall asleep, you might find yourself still wide awake at 2 AM, battling insomnia. If you keep battling insomnia, you are putting yourself at greater risk for Alzheimer’s Disease.

It’s like that children’s book, If You Give a Mouse a Cookie: a nap during the day sets off a whole chain of unintended consequences which ultimately lead right back to where you began: with the need for sleep. Which you should try, best as you can, to get only at night, following your body’s own circadian rhythm, so that by the time you hit the pillow, you stay there sleeping on it until the sun comes up.

If a nap is a regular feature of your day, this week you’re going to try to break this habit. It may mean you get sleepy before your normal bedtime. We just ask only that you observe your body’s own natural rhythms and honor them. (But without a nap during daylight hours, please.)

One caveat: if you had to stay up way too late one night this week for work or play, or you have jetlag, or you are ill with a cold or the flu, then of course take that nap. Your body needs it.