The Truth about Sleep Debt
From The Good and Bad News About Your Sleep Debt (Forbes, 2/23/20145)
“Sleep, science tells us, is a lot like a bank account with a minimum balance penalty. You can short the account a few days a month as long as you replenish it with fresh funds before the penalty kicks in. This understanding, known colloquially as “paying off your sleep debt,” has held sway over sleep research for the last few decades, and has served as a comfortable context for popular media to discuss sleep with weary eyed readers and listeners.
The question is — just how scientifically valid is the sleep debt theory?“
The article goes on to describe recent research to test four things that sleep is know to influence:
- attention,
- stress,
- daytime sleepiness, and
- low-grade inflammation.
To establish a baseline, study participants slept eight hours a night for a week in a lab where they were monitored and had blood work done. Next, they went an entire work week with only 6 hours of sleep each night, followed by three days with 10 hours of sleep. Did they recover from sleep debt?
Actually, three of those things measured seem to recover, but Attention did not, and that has at least two serious implications: safety and productivity.
SAFETY — The National Transportation Safety Administration says that driving drowsy with impaired attention is responsible for over 100,000 auto accidents per year, resulting in 1,500 deaths, 75,000 injuries, and over $12 billion in monetary loss every year. What worries me is just how many people drive drowsy and who might be approaching me when there’s no median to separate us. In a poll by the National Sleep Foundation, 60% of Americans said they have driven while feeling sleepy and 37% admitted to actually having fallen asleep at the wheel in the past year.
PRODUCTIVITY — School, work and athletic performance are all affected by sleep, or the lack of it, but at what cost? A 2011 Harvard study measured $63 billion/year in lost worker productivity from short sleep in the corporate workplace. Since the study didn’t include small businesses or the compounding effect on lifetime earning capacity, I developed a spreadsheet model to test my hypothesis and conservative assumptions, knowing that’s it’s nearly impossible to actually study that.
My spreadsheet starts with a new college graduate entering the workforce at $50K/year and then applies estimated career advancement, including duration and sizes of raises & promotions, as well as health impacts that can shorten the career and cause a drain on accumulated wealth rather than adding to it. The net lifetime impact from impaired attention, creativity, decision making, focus, judgment, memory, and patience totaled over a $8 million for the average college grad.
Although not included in the model, I believe the effect of short sleep on children can be even more profound, especially while their IQ is developing. Sleep impacts their learning ability, memory, focus, and grades, as well as what college they qualify for, what starting salary they can command, and what they will ultimately contribute to society.
The impact of not getting enough sleep is HUGE, and you can’t just make up for it on weekends. There’s a message here for parents and for all of us.