Working shifts and struggling? Learn how to adjust and get some sleep.
When working the night shift, do you have trouble concentrating? Then, when you get home from work, do you struggle to get to sleep (or stay asleep), even though you're tired? If that sounds familiar, you've felt the powerful effects of your circadian rhythms. Understanding how they affect you can help you develop strategies to better handle shift work.
The word "circadian" comes from a Latin phrase meaning "about a day." Human circadian rhythms are daily, or circadian, patterns to certain physical functions. The hundreds of functions that follow or are influenced by circadian rhythms include body temperature, blood pressure, and hormone and digestive-juice production. They're all controlled by your biological clock, a tiny clump of brain cells known as the suprachiasmatic nucleus (SCN). The SCN is strongly influenced by the daily change between sunlight and darkness. Morning light promotes wakefulness, and darkness sets the stage for sleep. What time you choose to sleep also affects your circadian rhythms.
All of these factors-circadian rhythms, cycles of light and dark, and your sleep patterns-combine to create your daily alertness curve (see illustration). Most people are more alert in the morning and early evening and less alert during the afternoon and overnight hours.
In essence, our circadian rhythms program us to sleep at night and to be awake in the daytime. When you go onto the night shift after keeping a day-shift schedule for several days, your circadian rhythms are out of sync with your new schedule. This can lead to fatigue, irritability, errors, and accidents.
How to put this knowledge to good use? Follow these tips:
* Eat right. Because your stomach doesn't digest food well at night, avoid eating heavy, greasy food after midnight. You're better off with light, healthy snacks.
* Prepare for night shift. You can help adjust your circadian rhythms for the night shift by staying up late and sleeping late before your first night shift.
* Sleep wisely. Ups and downs in circadian rhythms prompt a builtin alertness lull during the afternoon. This serves as the ideal time to nap.
* Avoid morning light. Morning sunlight acting on the SCN promotes wakefulness, even if you've been up all night. So when you come off a night shift, minimize your exposure by wearing dark sunglasses during your drive home and sleeping in a room with dark window coverings.
Wondering if your rhythms will adjust? They do shift when you start a nighttime schedule but only by an hour or so per day for most people. So when you work three or four straight nights and sleep during the day, your body partially adapts to your new schedule. However, the adaptation process starts all over again if, on your days off, you switch back to sleeping at night.
Daily alertness level
The alertness yo-yo: This chart shows how alertness fluctuates based on how long falling asleep at different times typically takes. For example, around 6 p.m., it might take almost 20 minutes; at 6 a.m., just 5 minutes.
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