How to Improve Employee Productivity: Start With Sleep

Most workplaces reward what people do while they're awake. Underneath that sits a belief: sleep is time taken away from productive work. Here's the thing. It works the other way around.

Here's how I explain it. Think of the brain as an engine: being awake produces exhaust, and sleep is when we clear it. Short on sleep, the exhaust builds up, and the cost lands on attention, reaction time, mood and judgment. Sleep loss can also impair decisions that involve the unexpected or changing plans.^[10]

Emotions shift too. The prefrontal cortex is the CEO of the brain: reason, logic, decision-making. It's also the brake pedal. The brain's emotional center, the amygdala, is the gas pedal. When we're short on sleep, the gas pedal and the brake get disconnected. In a small study of people kept awake for a night, the amygdala reacted more strongly to upsetting images, and its link to that brake weakened.^[11] Little things that wouldn't normally bother us become big things.

It reaches the team, too. After a night of poor-quality sleep, leaders in one daily study were more hostile toward staff, and their teams less engaged.^[12]

On some performance tests, yes. In a study of transport workers and army personnel, performance after 17 to 19 hours without sleep matched or fell below that at 0.05% blood alcohol.^[2] An earlier paper in Nature found a similar pattern on a hand–eye coordination task: after roughly 17 to 19 hours awake, in the early hours of the morning, performance matched 0.05%; after about 24 hours, roughly 0.08 to 0.10%.^[3]

Think of that. Wake at 6 a.m., and you pass 17 hours awake at 11 p.m.

Short nights add up, too. In one small lab study, four nights of five hours in bed slowed reaction time about as much as a blood alcohol level of roughly 0.05%, and one full night of sleep largely restored it.^[4]

Your people may be strong and proud of their stamina. They still aren't tough enough to beat this one. The good news: a long day is a risk you can see coming and plan for.

In a well-known experiment, healthy adults limited to six hours or less in bed a night for two weeks saw performance fall to a level equivalent to up to two nights of total sleep deprivation. Yet their sleepiness ratings barely rose after the first days, and they were largely unaware of the decline.^[5]

I hear it all the time: "Glenn, I can function really well on five hours." I'm sorry. You may feel like you're great, but you aren't your best self when you're sleep deprived.

For leaders, that means asking people how they feel is not a safety system. Build checks into the work itself.

Researchers call it presenteeism: being at work but not working at your best.

For your company

• Fatigue-related lost productivity was estimated at about US$1,967 per employee per year (2010 study): an average across 4,188 employees at four US companies.^[13]
• US workers with fatigue (from any cause) cost employers an estimated US$136.4 billion a year in health-related lost work time, US$101 billion more than workers without fatigue.^[14]
• Insomnia was linked to about US$2,280 a year in lost work performance per worker who has it, in an industry-funded survey of insured US workers.^[15]

A rough illustration: for 500 employees, US$1,967 each (2010 study) is roughly US$1 million a year (500 × US$1,967). That is simple arithmetic from one study, not a NEOS result. Your number will differ.

For the economy as a whole

• United States: insufficient sleep costs up to US$411 billion a year (2.28% of GDP, 2015 dollars), and about 1.2 million working days lost.^[1]
• Canada: up to about C$27 billion a year (1.35% of GDP), and about 78,000 working days lost.^[1]

These RAND figures are model-based upper estimates for a whole economy, not a company's bill. Short sleep is common among US workers: 35.6% in 2018.^[16]

That's the bad news. Here's the good: just because it's normal doesn't mean it's healthy, and it doesn't mean it's inevitable. I think of workplace sleep support as cost recovery, not a cost. You're already paying for tired days.

People with sleep problems get hurt more often. A review of 27 studies, covering 268,332 workers, found that people with sleep problems were 1.62 times more likely to be injured at work, and the authors estimated that about 13% of work injuries could be attributed to sleep problems.^[6] The studies were observational, so this is an estimate, not proof of cause. Even a small loss matters: on the Monday after the spring clock change, when people sleep about 40 minutes less, US mining data showed more workplace injuries, and more severe ones, than on other days.^[17] That is mining data, so we shouldn't stretch it to every workplace.

Now, let me be very clear. You cannot manage fatigue. The only way to manage fatigue is to get the sleep you need. What you can manage is the risk: find when your people are most exposed, and put your effort there. The American College of Occupational and Environmental Medicine has published guidance on how to do this. It's called fatigue risk management.^[18]

For around-the-clock operations, see our work for first responders and shift workers.

It's not just what you do that matters, it's when you do it. Circadian rhythms are daily biological rhythms of physiology and behavior. We all have them. This part is well-established science.

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Two dips matter most. The mid-afternoon lull often lands on the 3 p.m. meeting, a shift change or the drive home. The overnight low, roughly 2 to 6 a.m., matters for anyone working nights. Road-safety data show both: in UK data, sleep-related crashes peaked around 2 a.m., 6 a.m. and 4 p.m.^[8] Road accident risk shows a clear daily rhythm, with a major peak around 3 a.m.^[7] Again, that's road data.

We need to stop fighting our physiology and start working with it. In a German factory study, researchers adjusted shifts to workers' chronotype, their natural timing as an early bird, a night owl or something in between. In this small study, workers with the most extreme body clocks said they slept longer and better on workdays, and reported better well-being.^[9]

I'm not a management guy, and I'm not a union guy. I'm a science guy.

Every workplace is different, so start with a day in the life of your workforce. And I'll be honest: the goal isn't perfect sleep for everyone. It's the best sleep possible given the demands of the job.

Fighting the 3 p.m. slump? Don't push through. Work with your body clock: timing is something you can change.

Shift workers are a different case: planned naps in fatigue-risk zones (see our shift worker guidance). Otherwise, it's entirely up to you how far to take these. If you snore loudly, wake up gasping, or still feel exhausted with a steady sleep window, talk to your physician.