Your natural sleep-wake cycle — The Circadian Rhythm

Our circadian (Latin for “approximately one day”) rhythm is a cycle of about 24 hours that is linked to the rising and setting of the sun. Deep in our brains, a tiny, powerful cluster of nerve cells called the suprachiasmatic nucleus (SCN) works 24/7 as our internal clock, programming key activities such as cell regeneration, detoxification, patterns of brain activity, and production of hormones that regulate the sleep-wake cycle.

When it gets dark, your SCN begins to lower body temperature and also signals the release of melatonin, the hormone that makes you sleepy. But exposure to light at night — both natural and artificial — triggers an increase in body temperature, along with the release of “wake-up” hormones like cortisol. Light exposure also inhibits melatonin production. Because these internal pathways are so sensitive to light and darkness, it is easy for them to be thrown off — that’s why just switching on the lights for a few seconds can shift your circadian cycle by more than 40 minutes!

We all have an internal body clock that tells us when to sleep and when to wake in a 24-hour period. When that internal sleep-wake cycle gets disrupted, a circadian rhythm disorder may develop.

For most sleeplessness can be brought on through the subtle and ongoing physiological imbalances that are responsible for upsetting their inner clocks. These include hormonal imbalance, diet changes, stress, and certain daily habits. This circadian disturbance can result in daytime fatigue and night time insomnia, problems that become harder to shake over time if not addressed quickly. Sleep deprivation can result and have serious consequences. Car accidents, mood disorders and an increase in medical problems occur more frequently in individuals who are sleep deprived. There are ways to prevent circadian rhythm disorders and get the rest your body needs.

1. Reduce jet lag. The body does not adjust immediately when travelling to a new time zone and jet lag may result. Get on local time at your destination as soon as possible. If it is daylight, get some sunshine. Avoid alcohol and caffeine which can slow down the adjustment process for your body.

2. Avoid the swing shift. People who work overnight or keep changing shifts can develop circadian rhythm disorder. If it is impossible to avoid working overnight, make your bedroom conducive to sleep. Block out all sunlight and noise. Keep the room cool.

3. Skip daytime naps. Even a short nap can throw off your regular sleep-wake cycle. Instead of a nap get some fresh air, go for a walk or go to bed a little earlier to catch up on sleep.

4. Make lifestyle changes. Certain medications can disrupt sleep cycles. Ask your physician about side effects. Cigarette smoking and drinking alcohol can disrupt circadian rhythms. Avoid both at least 4 hours before going to sleep.

5. Control pre-existing medical conditions. Some medical problems such as chronic obstructive pulmonary disease and thyroid problems can interfere with sleep. With continuous interruptions, your circadian rhythm may get disrupted. Treat current medical conditions before circadian rhythm disorders develop.

6. Alleviate stress. If you have a hard time falling asleep repeatedly, delayed sleep phase syndrome, which is a circadian rhythm disorder, can develop. Find ways to lower stress. Start an exercise program, meditate or talk with someone you trust. Find a bedtime ritual that helps you relax such as taking a bath or reading.

Fortunately, your circadian rhythm can reset itself — up to a point. For instance, when you have a newborn baby, or work the night shift, or travel across time zones, your inner clock will adjust to the change. While this may not be a long-term solution, it does enable you to function in the short term. If you pull an all-nighter, can't sleep, change time zones, have jet lag, etc you are less likely to suffer for days while your body attempts to re-adjust. Research suggests that humans can regulate their circadian rhythm, or biological rhythm, through food.

How does this work?... By not eating for a short period of time.

If you know you are travelling internationally and know you will end up in an entirely different time zone... plan for it. If you are travelling to Tokyo and you want to get your body adjusted to the breakfast schedule there do some advance planning. Figure out when their breakfast time is and when then count back 12 to 16 hours taking into account your own time zone, travel time, etc. Scientists say you can get away with re-setting your body clock by not eating for 12 hours but for most people 16 hours works the best. Don't eat, until you are in your new time zone. You will probably still feel sleepy but remember, it's much better to have one day of weariness than to feel that way for 3 days.

Adapted from How to Reset Your Body Clock | http://www.ehow.com/how_5511991_reset-body-clock.html#ixzz1BoKlGieL