What Your Midlife Sleep Patterns Can Reveal About The Length Of Your Career

Most of us treat sleep as the flexible part of our schedule, the thing that has to give when work gets busy or the calendar gets out of hand. But a large new study out of Finland suggests that trade is pricier than it looks.

Researchers tracked how working adults slept at midlife, and how that impacted their careers.They found that poor sleep quality was associated with an earlier departure from the workforce. Not by days, but months, and in some cases years.

Plenty of studies have examined why people leave work early, from early retirement to exits driven by disability and poor health. But according to the researchers, none had asked whether adequate, good-quality sleep helps people stay.

To find out, they pulled data from two long-running observational studies. The first, the Finnish Public Sector study, followed over 70,000 public sector employees between 2000 and 2016 (80% of them women). The second, the Health and Social Support study, tracked a random sample of over 6,000 Finnish working-age adults from 1998 to 2013.

Sleep information came from the first survey each person completed after turning 50. Usual nightly sleep was sorted into short (under 7 hours), mid-range (7 to 8½ hours), and long (9 or more hours). Sleep problems from the previous four weeks, including trouble falling or staying asleep, waking too early, and sleep that left people unrested, were grouped as none, moderate (two to four nights a week), or severe (five nights a week up to nearly every night).

Compared with people who reported no sleep problems, those with moderate disturbances could expect to work nearly 5 fewer months. Those with severe disturbances could expect 8 fewer months.

In plain numbers, working life expectancy after age 50 was 13 years and 5 months for people with no sleep problems, 13 years for those with moderate problems, and 12 years and 10 months for those with severe ones.

Based on this data, you may expect the takeaway to be to sleep as much as you can to extend your career. But this isn't the case.

Short and mid-range sleepers landed in exactly the same place, a working life expectancy of 13 years and 2 months, with no clear difference between them regardless of sex or job type. But long sleepers were the outliers.

Among public sector employees, sleeping 9 or more hours a night was associated with a working life expectancy of 12 years and 5 months. When compared to people getting 7 to 8½ hours, the 9-plus group could expect around 9 fewer working months in the public sector study.

As with many health conditions, the burden here is not evenly shared. Researchers compared participants in professional jobs or with high education who also had no sleep disturbances and short or mid-range sleep, with participants in routine jobs or with low education who also had severe sleep disturbances or long sleep.

The gap between those two groups widened to roughly 1 year and 5 months in the public sector study and a full 5 years in the community sample.

Among 50-year-old public sector participants, the longest working life expectancy (around 13 years and 7 months) was seen in men and women with professional jobs and short nightly sleep. Highly educated women had the longest working life expectancy (about 11½ years). The shortest in both groups, only around 6 years and 5 months, was seen among men in routine jobs or with low education who slept 9 or more hours a night.

Healthy sleep didn't just extend working years overall, it disproportionately benefited people who already had more career advantages. The absence of healthy sleep hit hardest for people who already faced more workplace disadvantages.

This becomes an increasingly real concern as retirement ages continue to creep up. Statutory retirement ages have been rising in more than half of the countries in the Organisation for Economic Co-operation and Development (OECD), a response to aging populations across the global. This means more people are being asked, or are required, to stay in the workforce longer than previous generations.

Plenty of research has looked at why people leave the workforce early, from disability to poor health to burnout. But this is the first study of its kind to specifically connect sleep health to how long someone stays employed. If governments and employers want people to work longer, this research suggests sleep (and wellbeing more generally) is an important piece of the puzzle.

The study's authors point to workplace-level solutions rather than putting the burden solely on individuals to "fix" their own sleep. Specifically, they suggest workplace health interventions, whether it be something as simple as offering educational resources, or more involved options like connecting employees with therapists to treat insomnia.

Many people think of sleep as determining how tomorrow feels, but it may be determining much more than that, especially in midlife.

Keep your eye out for both chronically disrupted sleep and a standing 9-plus-hour habit—both are signals worth investigating.