Dangerous Situations Can Happen With Lack of Sleep

Several options of getting the sleep you need, including napping and getting away from shift work.
Dangerous Situations Can Happen With Lack of Sleep
Christopher Barnes, Ph.D., assistant professor of manage-ment at the Foster School of Business at the University of Washington in Seattle.

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Sleep is a fundamental human need. You can’t wish your way out of it, you can’t tough your way out of it, you can’t beat the system.” Those are the words of sleep and fatigue expert Christopher Barnes, Ph.D. The assistant professor of management at the Foster School of Business at the University of Washington in Seattle adds, “People are starting to realize that we’re at an unsustainable level of sleep loss. We sleep less every decade.”

Barnes says the research, including his own, is clear. “It’s very consistent across multiple studies. When people are short on sleep, they’re more likely to be involved in workplace accidents. It influences your judgment and actions in a way that increases your hazard of being injured.”

His research involved more than a half-million mining injuries over a 25-year period on one specific day: the Monday after daylight saving time begins. “There is a spike of 5.6 percent in workplace injuries,” he says of his findings. “The severity, measured by the number of lost workdays, goes up by more than 50 percent.”

In fall, when we gain an hour, there is no significant difference in sleep, number of injuries or severity (Changing to Daylight Saving Time Cuts into Sleep and Increases Workplace Injuries, Christopher M. Barnes and David T. Wagner).

The increased risk applies to both short-term sleep loss, as in Barnes’ research, and long-term sleep loss that others have studied. A 2014 analysis of 27 studies (Sleep Problems and Work Injuries: A Systematic Review and Meta-Analysis by Katrin Uehli, et al) showed sleep problems were responsible for a 60 percent increase in injuries and contributed to about 13 percent of all work injuries.

The loss of sleep is called sleep debt and builds up over time. “You may have had eight hours of sleep last night, but if you only had four hours the nights before that, you’re carrying some sleep debt that will influence your injury risk today as well as your other cognitive functions,” adds Barnes.


Fatigue is related to sleep loss in that it reduces your alertness. “People perform worse over longer and longer shifts,” he says. “It seems to be especially bad once you pass somewhere around nine or 10 hours. We’re setting them up to make mistakes that can harm them that they wouldn’t make if they were better rested.”

Barnes comes from a military background where he says the attitude is similar to that of many people. “The assumption is that people should man up, drink some caffeine and you can push through it.”

He cites the crab boats made famous on TV as a prime example. “It’s easy to rationalize. ‘We’re in a really sweet crab spot, so let’s work a few more hours. I’m a tough guy so I’ll just push through it and everything will be just fine.’ My research was done on miners; they are tough people and they’re vulnerable to the effects of lost sleep. Research with Navy Seals showed the same thing with their cognitive performance on various tasks that we see with normal people.”

Rotating shifts, he says, “are a beast” that cause people to suffer from effects similar to jet lag. “If you skip over eight time zones to travel to another country, you’re going to really struggle to adapt your sleep pattern. It’s the same thing when we rotate people across shifts.”

You can adapt your sleep schedule by about an hour a day, research has found. So if you switch to a different shift, it will take about eight days to get used to the schedule. “For those eight days,” Barnes says, “you’ll have a hard time being asleep when you want to be asleep and a hard time being awake when you want to be awake. You might doze off while you’re working, or at least be highly fatigued and low in alertness.”

The more frequently you rotate shifts, the more frequently you have to begin the process. If you rotate shifts every week, you will never get in sync and will always be adapting to a new sleep schedule.

Barnes says there is some disagreement about erasing sleep debt by catching up, such as sleeping in on weekends. Whether it helps or not, it does create other issues. “It’s disruptive to your future sleep. If you want to have a nice, strong sleep system, you should have a clear pattern and consistency with what time you go to bed and what time you get up. So when you sleep in on the weekend, you’re shifting your entire sleep schedule to be a few hours later. Then, Monday morning, you have to shift again to make everything earlier. It’s like putting yourself through jet lag every Monday.”


There are obvious signs that you are being affected by the lack of sleep: droopy eyes, difficulty concentrating, grumpiness. “Those are the easy ones,” he says.

“The one we don’t typically think of is how long it takes you to fall asleep.”

You might think that getting to sleep right away is a good thing, but it’s actually a symptom of sleep deprivation. “It indicates you’re carrying a lot of sleep debt and your body is trying to get right into sleep to try to discharge that debt. That should be a clear indicator that you’re not getting the sleep that you need.” He says it should take around 20 minutes to fall asleep.


Several years ago, NASA found that naps of about 30 minutes increased cognitive performance by 34 percent and alertness by 54 percent. Google has nap stations, pilots can now take naps on international flights, Huffington Post encourages napping. Ben & Jerry’s provides both nap rooms and free ice cream. Other major companies have embraced workday snoozing, including Nike, the New York Times, Pizza Hut, Time Warner and Metronaps, which makes sense since they make chairs designed for napping at work.

“Naps are mostly a good thing,” says Barnes. “It’s helpful, you get some restoration and you’ll perform better for the rest of the day.”

But be careful — you can make things worse. “If you’re in a deep cycle of sleep when you wake up from your nap, you’ll experience sleep inertia. You’ll wake up groggy with that zombie-like feeling where you’re not all the way awake. For some period of time you’ll be at less than optimal levels of effectiveness and have a hard time concentrating and working.”

A nap can also disrupt your sleep rhythm. “Some people have a hard time getting to sleep at night after they’ve taken a nap during the day. For some people, a nap is just stealing sleep from the future.”

Barnes says naps can be very valuable if they are around 20 or 30 minutes. “The longer the nap, the more restoration that will occur. But the longer your nap, the more likely you’ll enter one of those deeper phases of sleep and risk sleep inertia.”

While a nap is one way to make your life safer, Barnes says he would prefer that people just get enough sleep in the first place.


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