What is Sleep Debt & How Do You Catch Up on Sleep?

We break down what sleep debt is, the impact it has on your body, and the most effective ways to “catch up” on lost sleep.

Roughly 1 in 3 adults suffer from sleep debt on a regular basis, according to research from the CDC. And given that the data is based on self-reported stats of whether or not people get 7 hours of sleep per night, it’s very likely the actual numbers are significantly worse.  

What Is Sleep Debt?

When you don’t sleep as much as you need to, you start to accumulate sleep debt. Also known as a sleep deficit, sleep debt is the difference between the amount of sleep your body requires and the amount you actually get. Sleep debt builds up over time, so by sleeping less than usual for multiple nights in a row your sleep debt can progressively get worse and worse.  

What Happens When You Don’t Get Enough Sleep?

The National Sleep Foundation recommends adults get 7-9 hours of sleep each night. However, an individual’s nightly sleep needs vary due to a number of factors (more on this later). When you don’t meet your nightly sleep need and sleep debt starts to accrue, you begin to become sleep deprived. In the short term, the side effects of sleep deprivation may include:

• Poor concentration
• Decreased focus and alertness
• Moodiness
• Daytime sleepiness
• Increased anxiety
• Reduced coordination and athletic performance
• Elevated stress hormone production
• Lower energy expenditure and greater drive to eat, which may cause weight gain

Over the long term, chronic sleep loss can lead to:

• Increased risk of Type II Diabetes, heart disease, and cancer
• Lower levels of appetite-control hormone leptin, creating a higher risk of obesity
• Reduced immune system functioning and greater risk of infections
• Dementia
• Depression and other psychiatric disorders

Can You Make Up For Lost Sleep?

“The way sleep debt works is that it follows you around for a few days,” says WHOOP VP of Data Science & Research Emily Capodilupo (Podcast No. 57: Naps--Your Greatest Recovery Amplifier). If you don’t catch up on last night’s lost sleep tonight, you’ll continue to feel the effects of it tomorrow. And while you can’t go back in time and make up for past sleep that you’ve lost, there are several things you can do to counteract your recent sleep debt and set you on the right path going forward.  

4 Tips For Catching Up On Sleep Debt

The obvious way to catch up on sleep debt is to go to bed earlier than usual (or sleep in later) and get more recovery sleep tonight. Since that’s often harder than it sounds, here are some other things you can do to help combat sleep debt.

1. Make efforts to decrease sleep latency (the length of time it takes you to fall asleep).

If an earlier bedtime is not an option, the least you can do is try to spend more of your time in bed asleep. Things like avoiding screened devices in bed, lowering the temperature of your bedroom, and blocking out as much noise and light as possible can all help you get to sleep more quickly. Learn More: 28 Simple Techniques to Fall Asleep Fast

2. Don’t plan to catch up by sleeping in on weekends.

You're not going to be able to fix 5 nights of poor sleep during the week with a couple good ones on the weekend. Additionally, altering your normal sleep patterns with a different schedule on the weekends throws off your circadian rhythm (the body’s 24-hour internal clock) and leads to lower quality sleep overall. Learn More: How to Reset Your Circadian Rhythm & Fix Your Sleep Schedule

3. Improve sleep efficiency with sleep consistency.

Conversely, a consistent sleep schedule where you go to bed and wake up at regular times each day reinforces your circadian rhythm and increases the efficiency of your sleep. In fact, locking in your sleep consistency can actually enable you to get more sleep while spending less time in bed. Learn More: The Benefits of Sleep Consistency

4. Nap.

If you can find a way to squeeze one in, an afternoon nap is often the most effective way to catch up on your sleep debt. For example, if you have an hour of sleep debt hanging over you from last night, a quick 30-minute snooze can cut that in half and boost your chances of making up the rest tonight. Learn More: Ideal Nap Length, Benefits & Reducing Sleep Need  

Track Sleep Debt & Get All the Sleep You Need with WHOOP

WHOOP tracks your nightly sleep in detail, including the time you spend in each stage of sleep and your overall sleep efficiency (the percentage of time in bed that you’re actually asleep). Our Sleep Planner feature incorporates your physiology, amount of recent sleep, and the strain put on your body during the day to calculate exactly how much sleep you need.

WHOOP tracks your sleep debt and calculates how much sleep you need in order to catch up.

Based on this, the Sleep Planner then tracks any sleep debt you accumulate and factors it into your sleep need the following night, making a recommendation for when to go to bed in order to best catch up on your sleep. Learn More: The Optimal Sleep Playbook - Managing Sleep Debt with WHOOP