Harness your body's natural rhythms to feel better, think smarter and exercise harder, today and every day.
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Getty ImagesYou know the expression "Timing is everything"? Turns out it applies to your health and happiness, too. Our bodies run on circadian rhythms—subtle but significant patterns in our physiological processes that repeat every 24 hours. These daily dips and surges are governed by the brain's internal clock (a group of brain cells inside the hypothalamus that are cued by changes in light) and affect everything from your flexibility and endurance to your metabolism and creativity, says Matthew Edlund, MD, director of the Center for Circadian Medicine in Sarasota, Fla., and author of The Body Clock Advantage. According to the emerging field of chronobiology, it's possible to capitalize on these cadences. By knowing when they happen, you can sync your schedule to your natural cycles and live every hour to the fullest.

7:00 A.M.
Let some light in
Crack open the blinds and do a few stretches or sip your morning coffee in front of the window. "Sunlight signals the brain's pineal gland to stop producing melatonin, the hormone responsible for sleepiness, so you feel more alert," explains Steve Orma, PsyD, a psychologist in San Francisco who specializes in sleep disorders. Sunlight also speeds up a natural rise in body temperature that helps you feel increasingly clearheaded through the morning.

7:30 A.M.
Step on the scale
Over the course of a normal day, you can gain up to 3 pounds in water weight—but you lose most of it overnight via sweat and bathroom trips. So for the most accurate (and flattering) read, weigh yourself in the a.m. after you've gone to the bathroom, suggests Alissa Rumsey, RD, spokesperson for the Academy of Nutrition and Dietetics.

8:00 A.M.
Don't delay breakfast
Eating 30 to 60 minutes after waking kick-starts your metabolism and a day of steady, efficient calorie burning, Rumsey says. But what you eat is key: A pastry or other refined-carb-heavy treat will cause your blood sugar to surge, then plummet, leaving you cranky and craving more food. To stay energized, you need a combo of fiber, fat and protein. (Think a veggie omelet wrap.)

10:00 A.M.
Have that procedure you've been putting off
If you need to go under the knife (say, for a biopsy or major dental work), now is the time. A 2006 Duke University study found that the odds of anesthesia-related complications are lowest between 9 a.m. and noon. One reason could be that doctors function at their highest mid- to late morning, during a natural peak in cognitive clarity.

11:00 A.M.
Ace a presentation
As your body temp crests, so does your mental energy, Dr. Edlund says: "You're sharper and more able to put thoughts together." Seize this hour to nail a pitch or power through a complicated report.

1:00 P.M.
Cave in to your fro-yo craving
Right after you finish a lunch with protein and healthy fats. The nutrients in a turkey-avocado sandwich, for example, will reduce the spike-and-crash effect of your mint chocolate chip, says Holly Phillips, MD, a women's health specialist in New York City. Bonus: Enjoying dessert after lunch rather than dinner means you have more time to burn off the added calories.

2:00 P.M.
Head to the post office
Your body temperature is sinking now, so you may feel drowsy, says Robert Matchock, PhD, associate professor of psychology at Pennsylvania State University. According to one theory, this dip in energy can be traced back to our ancestors; it helped them sleep through the midday heat in Africa. No chance for a nap? Run some errands. Moving around will raise your temperature, Matchock says: "Exposure to the sun will give you an extra lift."

3:00 P.M.
Update your status
Facebook's traffic spikes at this hour, making it the best time to connect with your friends. Our social activity ramps up later in the day, and this is when people start to reach out, Dr. Edlund explains.

Next Page: 5:00 P.M. Kick butt at spin class [ pagebreak ]
5:00 P.M.
Kick butt at spin class
You're at the top of your game physically: Your body temperature is peaking, which means your joints and muscles are warmed up, Dr. Edlund says. Your hand-eye coordination is at its best. And your breathing is 18 percent more efficient than it was at noon, per a 2008 study in the International Journal of Clinical and Experimental Medicine. It's no wonder most Olympic records are set in the late afternoon.

6:30 P.M.
Broach a touchy subject
Along with an uptick in energy in the second half of the day comes a boost in mood and positivity—which can make swallowing bad news a little easier, Dr. Edlund notes. If you need to, say, bow out of a friend's wedding party, she'll take it best in the early evening.

7:00 P.M.
Finish off your last glass of wine
It's ideal to stop drinking at least three hours before lights out, Orma says, to allow time for the booze to be metabolized. "If you drink closer to bedtime, you'll likely experience restless sleep once the alcohol's depressive effects wear off and your nervous system rebounds," he says.

8:30 P.M.
Run a bath
Your body temp drops again at night, but for some people the drop is steeper, so they nod off faster and sleep more deeply, according to researchers at Cornell University. To stimulate a quick dive in degrees, Orma suggests emerging from a steamy soak in the tub two hours before bed.

9:30 P.M.
Brainstorm themes for the charity fundraiser
As you wind down for the night, let creative sparks fly. A 2011 study in Thinking and Reasoning found that when you're less than 100 percent alert, you don't feel as inhibited and are more open to new ways of thinking that lead to novel ideas. (If you're a night owl, try brainstorming in the a.m.)

10:30 P.M.
Take your allergy meds
Due to fluctuations in hormones (such as cortisol) that affect immune response—and the fact that most plants release pollen shortly after dawn—your allergy symptoms are likely worst early in the morning, says Roger Emert, MD, an allergist-immunologist at NYU Langone Medical Center in New York City. But you can prevent sneezing and wheezing first thing in the a.m. by taking an allergy med like Claritin or Zyrtec before bed, Dr. Emert says. That way it's working when you wake, and you can start your day fresh.