Rotating Work Shift and Your Circadian Rhythm

by Patrick
(Hephzibah, Ga., United States)

Ok long story made short. How does this apply to someone who works a rotating/swing shift? Does anyone have a solution for that? Your biological clock and circadian rhythm are more or less permanently thrown into disarray. It is impossible to maintain a normal biological clock and circadian rhythm when you work a rotating shift.

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Kevin: Hey Patrick, fantastic question. Thanks for asking it. You're absolutely right to highlight the problems shift workers face with their circadian rhythm. In fact, it's something that has generated a large amount of interest and attention in the field of sleep research, and there is even a conditioned called "Shift Work Sleep Disorder" listed in the International Classification of Sleep Disorders. (Look on this page under Dyssomnias, Circadian Rhythm Disorders, C.2 and you'll see it right there.)

Sleep deprivation associated with shift work is a serious problem in many professions, personally for the workers, productivity-wise for the companies, and safety-wise for the public in some cases. In one study, over 7,000 rotating shift workers in petroleum, chemical, and manufacturing industries were asked whether they had ever fallen asleep on the job. Overall, more than 40% admitted they had one or more times. When divided up by shift time these numbers turned into 62% while on the night shift (approx. 12 a.m. - 8 a.m.), 35% while on the day shift (8 a.m. - 4 p.m.), and 25% while on the swing shift (4 p.m. - 12 a.m.). Interestingly, these numbers match up with biological clock alertness patterns if you have an understanding of how circadian rhythms typically operate (dip in alertness during the afternoon, higher alertness in the evening, much less alertness late into the night and early morning). (I don't have the exact reference to the study on hand--I'm reading secondhand about it from the Stanford Sleep Book. If anyone knows exactly what study this is, definitely post it in the comments.)

There are inevitable difficulties built into shift work when it comes to sleep, and there's only so much an individual can do to cope with constantly adjusting if they're on a swing schedule. One of the most promising solutions then, and one that is being realized more and more, stems from the businesses/employers themselves being cognizant of the detriments certain swing/rotating shifts can bring to their employees. Having the businesses learn about and work out the safest, most efficient, and healthiest schedules, and having them see it is in their own self-interest to implement those schedules, is key.

That said, for the individuals themselves who are working these types of shifts, it is so important to learn about and have a good understanding of their own biological clock and how it is influenced.

I've been working on getting an article on shift work and sleep up on the site to get into more detail about this. I have some writing already done for it, but it's going to take a bit more polishing before it goes up. I'll update this page with a link when it's ready.

Thanks again for the question Patrick. Are you a shift worker yourself, or just curious?

Warmly,
Kevin