Time Your Tasks: Are you most creative in the morning? Do more difficult chores then.
The Energizing Effect: Say you bounce out of bed ready to go. If you squander that energy fielding e-mails and reading, you'll have to work twice as hard on the tougher stuff in the afternoon, when fewer of your brain cells are firing. Be energy-efficient by matching tasks to your natural highs and lows.
Take a Tech Break: Turn off the e-mail, phone, and BlackBerry, and step away from the computer—just for a few minutes.
The Energizing Effect: Overdoing the tech is like bingeing on chocolate. "Too much makes you feel sluggish and scattered, and drains your energy," says Jon Gordon, author of The Energy Bus: 10 Rules to Fuel Your Life, Work, and Team with Positive Energy (Wiley). In fact, a Carnegie Mellon study shows that too much computer use can be potentially depressing, possibly because it's taking the place of face-to-face encounters. (So during your downtime, how about connecting with a real live person?)
Eat a Light Lunch: Forget the heavy, greasy stuff and go for veggies, complex carbs (whole grains), and low-fat proteins. And don't have wine or beer with the meal if you want to accomplish anything at all in the afternoon. Alcohol will make you tired.
The Energizing Effect: According to a study reported in the British Food Journal, a big lunch (1,000 calories) just about guarantees an afternoon energy dip. This is especially true if the meal was high in simple carbohydrates and fat. When you indulge in a huge meal, says Dr. Bauman, your heart has to work 25% harder to fuel digestion in the stomach and intestines, depriving your brain and other organs of what they need to keep going. "Add this to your body's natural circadian rhythm, which causes an afternoon slump, and you've got double trouble," says Dr. Bauman. The British study also shows that a small lunch may actually improve your performance, especially in the early afternoon. So do yourself a favor and fuel your body with only the good stuff. That way high energy—not that superstuffed feeling—will be your postmeal reward.
Get Moving: Everything you've ever heard about the energizing effects of exercise is true—even if you take just a quick, brisk hike, says Robert E. Thayer, Ph.D., professor of psychology at California State University, Long Beach. At work, walk over to talk to a colleague instead of e-mailing or calling. At home, dash around the house for five minutes putting stray stuff back where it belongs. Stretch, too—find the muscle groups that are tight and move them in the opposite direction. If you've been sitting at a keyboard, rotate your shoulders up toward your ears and down your back, like the shoulder blades are going to touch each other.
The Energizing Effect: Exercise pumps oxygenated blood to our tired cells, says Thayer. So when you're feeling slow and low, make movement an absolute priority. Do it even if—especially if—you really, really don't feel like it.