It's a complex brew of hormones that washes through our brain and body—and they're a powerful force.
But too much or too little can make a big difference in how you feel and what you do.
So what if you could harness your brain power to make the most of your day?
Nesita Kwan reports.
And you're off and running. If you're a nine to fiver, mornings are busy, but it may also be when your levels of Oxytocin, or the love hormone, are highest.
Dr. Leonard Cerullo, Neuro Scientist said "We probably are feeling very loving, very amorous toward the husband or the boyfriend or whomever."
Chicago Neuro-Scientist Leonard Cerillo says it can be a prime time for passion, and less private kinds of bonding as well.
Maybe an extra hug for the kids or a round of "I love You’s” before you head out the door.
Assuming a regular work day, these are the early work hours: when moderate levels of the stress hormone Cortisol are pumping through your brain.
"You're strong. You're alert. You're sensitive. You're insightful. Your body is charged up."
You're at your most creative, so brainstorm solutions to a problem now, or work on a new idea.
As your day progresses, German researchers say the amount of sleep inducing Melatonin drops.
In these middle hours, take on that challenging conversation, or the list of problem e-mails.
This is when people are generally quickest, best able to multi-task.
And then if you leave work content and energized: that may be because sleep friendly melatonin levels are now at their lowest.
For some it's an ideal time to exercise.
Of course, this all assumes a regular nine to five routine, but we now live in a 24 hour world, where flip flopping schedules are common.
"If you think about your life and you think about your daily activities, patterns begin to evolve,” said Dr. Leonard Cerullo. “I think it can be identified, but in order to identify it you have to be sensitive to it."
A new line of caffeinated chewing gum is causing jitters among health advocates and prompting federal officials to take a new look at the proliferation of jolt-infused foods, including those marketed to children and teens.
Stress, the slowing of metabolism of middle age, and hormone changes after having a baby are three main reasons why many people see the numbers on the scale going up. Dr. Mehmet Oz shares tips on how to shed those final 10 pounds.