Shives points out that people react very differently to caffeine, so you may want to start off with half a cup after lunch and see if that disrupts your nighttime sleep. Don't drink coffee in the late afternoon or evening.
As with naps, moderation is the key when it comes to caffeine. If you overdo it, you may set off a vicious cycle, making it hard to sleep at night so you are drowsier the next day. And many sleep experts advise against drinking caffeine after 2 p.m.
Myth: A candy bar or can of soda will give me a kick-start.
Fact: Sugar will give you a temporary lift, but when it wears off you're likely to be even more tired than before.
People are often tempted to seek out the soda machine or the candy counter when they hit that afternoon slump. When we are fatigued, our bodies often crave a rush of fuel to keep us going, and Shives says that studies bear out this anecdotal experience.
"Research shows that if sleep-deprived people are offered an array of foods, they disproportionately choose sugary and/or fatty items," she says. "Our bodies crave foods that have a high glycemic index because they provide a quick boost of energy."
The trouble is, when the sugar high wears off, you are likely to feel even more tired than you did before. One study found, for example, that an hour after drinking high-sugar energy drinks, sleep-deprived patients were sleepier and had more lapses in concentration than patients in the control group, who didn't drink the sugary drink.
To minimize afternoon drowsiness, Shives recommends that you eat a light lunch. "Avoid fats, sugars, and carbohydrates," she says. "Have some lean protein -- but be sure to keep it light."
Myth: Exercise will only make me more tired.
Fact: Moderate exercise can help combat drowsiness and leave you alert and refreshed.
Exercise is an excellent way to ward off an after-lunch circadian dip, says Shives. It doesn't have to be a big time commitment: "You don't have to spend hours at the gym," she points out. "A brisk 10-minute walk, or some vigorous stretching, will give you a quick pick-me-up."