Sleep Deep, Sleep Science

Can You Catch Up on Hours of Lost Sleep?


Q: I’ve heard the term “sleep debt” but have seen conflicting headlines on whether or not it can be repaid. If I miss a lot of sleep during the week, will sleeping in on the weekends counteract the health risks?

A: Most of my clients over the years have had more sleep debt than they have credit card debt. When you’re killing it career-wise, are fitting in social time, and are potentially also raising kids, it can be nearly impossible to get enough shut-eye.

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But as you cut an hour here and two hours there, sleep debt adds up just like the financial kind. Instead of draining your bank account, it drains your body and leads to major negative health effects, from short-term foggy brain to long-term inflammation and increased risk of obesity and heart disease.

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The short answer is this: you can make up for lost hours by sleeping in on Saturday and Sunday when it comes to counteracting some of the negative effects of sleep deprivation, but it’s still better to prioritize sleep daily.

Here’s a quick explanation of the research.

Can You Repay Sleep Debt by Snoozing?

First, the good news. Not getting enough sleep is clearly linked to weight gain, but recent research showed repaying sleep debt may counteract that effect.

In a study on more than 2,000 people who didn’t sleep enough during the week, sleeping in on the weekends was significantly associated with a lower BMI. The more sleep participants made up, the healthier their weights were.

Other studies have shown that measures of  “daytime sleepiness” and inflammation are significantly reduced after sleep debt has been repaid.

The same research, however, showed people weren’t able to bounce back as easily when it came to some negative cognitive effects of sleep deprivation, like attention span, and other research has backed that up. One very small study, for example, showed long-term sleep debt really threw off people’s mental acuity.

RELATED: Are Your Sleep Habits Messing with Your Mental Health?

An important point: that study was on long-term sleep debt, and that’s the kind I’d say you really want to avoid. If you only get five hours for a couple of days because of a big work event and a super fun night out with friends once in a blue moon, it’s likely fine to just let yourself sleep in before brunch that weekend. But weeks and weeks and months and months of not sleeping enough adds up.

According to a Harvard sleep researcher, “If you’ve shorted yourself on sleep for decades, you won’t be required to put in a Rip Van Winkle–like effort to repay the hours of missed slumber. Nonetheless, it could take a few weeks to recoup your losses.”

So, ideally, try to prioritize sleep the same way you would fitting in workouts. Make a daily effort to get enough—it’s just as important as eating your veggies.