If you thought pulling an all-nighter for work was a shortcut to being more productive, think again.
Scientists have reaffirmed that there's a sleep "sweet spot" — and it's between seven and eight hours a day. Though this number has long been known to sleep researchers, a new study emphasizes that not getting roughly the right amount of rest each night backfires big time when it comes to work, causing most to miss significantly more work days.
The study: Finnish researchers surveyed 3,760 men and women aged 30 to 64 on their sleep habits and number of missed work days over seven years, finding that both people who got much too little and far too much sleep. People who slept five hours a night or less or more than 10 hours more likely to take time off from work, missing between five to nine more days of work than those who hit the happy medium, and suffering insomnia-like symptoms, tiredness, interrupted early-morning sleep and needing sleeping pills.
The results, published in Sleep, are another affirmation that getting enough sleep is important to maintaining a healthy lifestyle. Being tired the next day won't just make you miserable, but it will have a detrimental effect on your ability to even show up at the office at all.
There's a strong message here for bosses, too: Overworking your staff until they don't have enough time to rest will cause problems down the line. If all the people involved in this study got the right amount of beauty sleep, the direct cost of sick time would plummet by up to 28%.
"Optimal sleep duration should be promoted, as very long and very short sleep indicate health problems and subsequent sickness absence," principal investigator Tea Lallukka told ScienceDaily. "Those sleeping five hours or less or 10 hours or more were absent from work every year for 4.6 to 8.9 days more, as compared to those with the optimal sleep length."
"Insufficient sleep, due to inadequate or mistimed sleep, contributes to the risk for several of today's public health epidemics, including cardiovascular disease, diabetes and obesity. Getting at least seven hours of nightly sleep is a key to overall health, which translates to less sick time away from work," American Academy of Sleep Medicine president Timothy Morgenthaler said.
Why it's important: If you think you're getting by with less sleep, you're probably wrong. Previous research has established that a small number of people may have a genetic mutation that allows them to sleep around six hours a night with few ill effects, but as many as 95% of people who think they're the exception to the 7- to 8-hour rule are wrong. Leading sleep researcher Hans Van Dongen told Vox that "[i]f you sleep much less than you need, we have good reason to believe that will impair your health."
So if you've been really burning that midnight oil to finish an important project or please your boss, this is yet more evidence that you're not doing yourself or your employer any favors. Unfortunately, in an economy where many of us are logging extreme hours, a lot of people don't have a choice.