When our rhythms are in sync, life flows easily. We have more energy, and everyday tasks are easier to perform. When we're 'in our rhythm,' we're more socially engaging and life is more satisfying. Athletes call this "Being in the zone" or "having their game on." It turns out that ‘finding your rhythm,” is more than psychological. We each have a body clock that regulates how we feel and perform. These rhythms, called circadian rhythms, are the signals our body clocks produce, and they affect every aspect of our life. They tell us when to wake up, be active, sleep and how energetic to be. Even how we socialize and feel are affected by circadian rhythms. In fact, these rhythms are so predictable, you can set your clock by them. That's where the term ‘body clock' comes from. Our body clocks have evolved to depend on the sun to function properly each day. The problem for most of us though, is that our lifestyle has changed dramatically over the last 50 years. We no longer get up with the sun, and we stay up hours after dark. This plays havoc on our body clocks—they don't get the signals they need and so don't produce the right hormones during the day.
A circadian rhythm is a roughly-24-hour cycle in the physiological processes of humans, animals and plants. The term "circadian" comes from the Latin circa, "around", and diem, "day", meaning literally "about a day." We now know there are clear patterns of brain wave activity, hormone production, cell regeneration and other biological activities linked to this daily cycle. The circadian "clock" in mammals is located in the suprachiasmatic nucleus (SCN), a distinct group of cells located in the hypothalamus. Destruction of the SCN results in the complete absence of a regular sleep/wake rhythm.
But recently, evidence has emerged that circadian rhythms are found in many cells in the body—outside the SCN "master clock" as well. Cells from many parts of the body appear to have "free-running" rhythms. So just when we thought that there was a master clock that dictated all the rhythms, it seems like rhythm is everywhere in the body...fascinating.