Almost everyone has fallen prey to the dreaded afternoon slump. You feel fine when you sit back down at your desk after lunch, but a couple of hours later, you can barely hold your head up. The reality is that you can’t completely avoid this desire to nap; it’s a natural part of your body’s circadian rhythm.
Michael J. Breus, clinical psychologist and author of “Beauty Sleep,” notes, “Right before you go to sleep at night, your core temperature begins to drop, which is a signal to the brain to release melatonin. The exact same thing happens on a smaller scale between 2 and 4 in the afternoon.” He calls this a “mini-signal” to take a nap.