We live in a culture that embraces this mantra: You snooze, you lose. But actually, the opposite may be true: A growing body of research suggests that what scientists call “sleep extension” may be highly beneficial for people who consistently skimp on shut-eye.
While you may have never heard of the term sleep extension, odds are you’ve probably done it. Sleep extension is the official term for when you intentionally increase your snooze time by an hour per night or sleep longer than eight hours per night for a stretch of several days. And depending on your sleep debt, doing this could help you become a healthier, more productive version of yourself.
In particular, sleep extension has been shown to be helpful for enhancing cognitive function, athletic performance, weight management, cardiometabolic health, and other aspects of physical health, especially among people who don’t get enough sleep on a regular basis. In other words, the detrimental effects of chronically sleeping too little are at least partially reversible.
Let’s take a closer look at the head-to-toe perks of sleep extension.
Sleep extension can lead to sharper minds and better moods
A study published in a July 2022 issue of the journal Sleep Health found that when adults ages 18 to 24 who consistently slept fewer than seven hours in a 24-hour period increased their “sleep opportunity” by 90 minutes, their daily moods improved, and so did their sleep quality.
In a study in a 2014 issue of PLOS One, researchers investigated the effects of sleep extension on people who regularly slept fewer than 6.5 hours per night and developed neurocognitive impairments as a result. After increasing their nightly slumber by an average of 11% and maintaining this increased sleep pattern for more than a year, the participants had noteworthy improvements in their global cognitive function, attention levels, memory, and executive functions. Previously, a study in a 2004 issue of the journal Sleep Medicine found that when college students extended their snooze time “to sleep as much as possible during a sleep extension period,” they gained substantial improvements in their daytime alertness, reaction time, and mood.
Sleep extension can lead to healthier diets and better weight control
In a study in an April 2022 issue of JAMA Internal Medicine, 80 adults who were overweight and habitually slept fewer than 6.5 hours per night were randomized to either a two-week sleep-extension intervention (increasing their nightly snooze time to 8.5 hours) or a continuation of their usual sleep patterns. Both groups were instructed to continue their usual daily activities, without any advice about diet or physical activity. After two weeks, those in the sleep-extension group were found to have decreased their calorie intake by an average of 270 calories per day.
The theory is that “when you get sufficient sleep, your body systems, particularly your appetite hormones, are better regulated, and your brain tells you to eat less, and you feel less hungry, making you want to consume fewer calories,” says study co-author Dr. Esra Tasali, an associate professor of medicine and director of the UChicago Sleep Center at the University of Chicago.
In addition, a study in a 2018 issue of the American Journal of Clinical Nutrition found that when adults who regularly slept for fewer than seven hours per night extended their nightly sleep over the course of four weeks, they naturally reduced their intake of dietary fat and free sugars, thus improving their overall diet quality.
How sleep extension improves overall health
As one group of researchers noted, “Sleep extension has the potential to attenuate obesity risk and cardiometabolic dysfunction,” given that it may improve blood sugar control, decrease blood pressure, and facilitate weight loss. A review of studies, published in a January 2022 issue of the European Journal of Cardiovascular Nursing, found that increasing sleep time by 51 minutes per night was associated with reductions in systolic and diastolic blood pressure among people with prehypertension or stage 1 hypertension.
Meanwhile, a review of studies published in a 2021 issue of the journal Primary Care Diabetes found that when healthy participants and those with diabetes engaged in sleep extension for seven to 14 days, their blood sugar control and insulin sensitivity improved.
On the other hand, skimping on sleep may contribute to increased universal inflammation, oxidative stress (an imbalance between unstable atoms and antioxidants in your body), sympathetic nervous system activation, endothelial dysfunction, and cholesterol abnormalities, notes Bilgay Izci-Balserak, Ph.D., an associate professor of sleep medicine at the University of Illinois Chicago. “Additionally, short sleep duration may lead to cardiometabolic disease by impairing glucose metabolism and dysregulating the neuroendocrine control of appetite, [blood] glucose, and caloric intake.”
In a completely unrelated perk, sleep extension may reduce pain sensitivity: In a study in a 2019 issue of Sleep Medicine, researchers had healthy adults increase their sleep time by nearly two hours per night for five nights and then measured their pain tolerance with a cold pressor task (which involves placing a hand in ice-cold water): They found that sleep extension increased the participants’ pain tolerance — the amount of time the person kept their hand submerged in the cold water — considerably above their baseline levels.
How sleep extension can even enhance sports performance
As far as athletes go, lengthening the person’s sleep duration even more dramatically may confer benefits on performance while competing. A study in a 2015 issue of Physiology & Behavior found that when members of a college varsity tennis team increased their nightly sleep time by approximately two hours, the accuracy of their tennis serves improved significantly.
Similarly, research in the journal SLEEP found that when men on the Stanford University men’s varsity basketball team increased their nightly sleep time — with a minimum goal of 10 hours in bed each night — over five to seven weeks, they improved their shooting accuracy (both their free-throw and three-pointer percentages) as well as their sprint times.
More recently, a study found that after five nights of sleep extension, professional baseball players reacted 122 milliseconds faster on a test of cognitive processing speed and 66 milliseconds faster on a test of selective attention while facing distractions. This is significant because, as the researchers note, it takes a fastball approximately 400 milliseconds to travel from the pitcher to the batter, which is why batters need quick reaction times. As a bonus, the players’ levels of fatigue, tension, and daytime sleepiness decreased by more than 33% after sleep extension.
The bottom line on sleep extensions
Tasali notes that it’s important to keep this in mind: “The minimum recommended sleep duration for an adult is seven hours, and the range for recommended sleep duration is from seven to nine hours depending on individual needs.”
If you’re not currently getting the optimal amount, you may be wondering how you can extend your sleep on your own. “Extending sleep may not be as hard as people think,” Tasali says. “In addition to following general sleep hygiene recommendations, small changes in behaviors around bedtime or in the morning can make a huge difference. For example, the most effective intervention in our sleep hygiene program was limiting the use of electronic devices before bedtime.”
Here’s another strategy that may help: “For those who don’t get enough sleep, a simple message could be to spend at least 8.5 hours in bed each night,” says Marie-Pierre St-Onge, Ph.D., an associate professor and director of the Sleep Center of Excellence for Research & Education at the Columbia University Irving Medical Center in New York City. “Now, that may not guarantee more sleep, so other things to consider to improve sleep are environmental conditions and daytime behaviors.” That includes sleeping in a room that’s not too hot or cold and is dark and quiet.
Izci-Balserak says other go-to sleep hygiene practices can help you extend your sleep, such as:
- Exercising regularly but avoiding strenuous exercise within six hours before bedtime.
- Getting adequate exposure to natural light during the day and limiting exposure to bright light in the evenings.
- Sticking with a consistent bedtime and wake-up time that allows you to get at least seven hours of sleep, even on weekends and holidays.
- Following a consistent, relaxing routine in the 30 to 90 minutes before bedtime, which Izci-Balserak says “can help train the brain to naturally feel tired when it’s bedtime.”
In addition to these sleep hygiene practices, using a wearable sleep tracker may help you extend your sleep duration, Izci-Balserak notes. In fact, a study in a 2019 issue of the Journal of Clinical Sleep Medicine found that using a wearable sleep tracker and an interactive smartphone app, along with receiving weekly coaching by phone, helped adults with prehypertension or stage 1 hypertension increase their sleep time and reduce their blood pressure after six weeks. After all, the data you get from a wearable sleep tracker can uncover factors that can help you get a long, restorative night of sleep and troubleshoot those that don’t.
When it comes right down to it, extending your sleep may be a powerful investment in your long-term health and functionality.