“Sleep is for the weak,” said no doctor ever. In fact, the opposite is true: if you want to be fit, healthy and resilient—both emotionally and physically—you need sufficient sleep. The National Sleep Foundation recommends seven to nine hours of sleep per night for adults aged 26 to 64. Yet more than a third of American adults do not get the sleep they need.
“Multiple studies on health outcomes and sleep have made it clear that consistent, good-quality sleep improves health and can extend life,” says physician Dr. Kyle Varner.
Research shows sleep affects virtually every facet of health and well-being. From weight management and heart health to learning, athletic performance and mental wellbeing, here are 13 reasons to prioritize sleep, along with practical expert tips to help you rest better.
Want to sleep better and have more energy while awake? Download Loóna, an award-winning sleep app that combines art, guided relaxation, storytelling and science to help people unwind and achieve more restorative sleep.
Sleep Can Improve Your Heart Health
Insufficient sleep can increase cardiovascular risk. A study from the University of Gothenburg found that middle-aged men who slept five hours or less per night had roughly twice the risk of experiencing a major cardiovascular event over the next two decades compared with men who slept seven to eight hours. Conversely, some research indicates that consistently sleeping much longer than average can also carry risk: people sleeping eight to nine hours showed a slightly higher risk of major cardiovascular events than those sleeping six to eight hours.
Expert tip: Avoid caffeine late in the day. Coffee, soda and other caffeinated drinks after mid-afternoon can interfere with nighttime sleep, says sleep specialist Whitney Roban, Ph.D.
Sleep Helps With Weight Management
Sleep plays a crucial role in regulating appetite, metabolism and blood pressure. Getting fewer than six hours per night is associated with higher body mass index (BMI) and an increased risk of obesity. Reviews of multiple studies show short sleepers—both children and adults—are significantly more likely to gain excess weight. Poor sleep disrupts hormones that control hunger and satiety, such as ghrelin and leptin, which can lead to increased appetite and calorie intake.
Expert tip: The blue light from screens suppresses melatonin and tricks your brain into thinking it’s daytime. Turn off electronics at least one hour before bed to support natural sleep onset, advises Roban.
Sleep Strengthens Learning and Memory
A well-rested brain is better at processing and retaining new information. Sleep consolidates recent learning into long-term memory and supports the acquisition of new skills. For example, a Northwestern University study found that a 90-minute nap improved participants’ performance on a musical task—participants made fewer mistakes on the melody that was replayed during sleep.
Expert tip: Keep a regular day-night schedule. The body operates on a circadian rhythm, so try to limit daytime napping and prioritize nighttime sleep, says Dr. Varner.
Sleep Boosts Athletic Performance
Sleep deprivation impairs strength, endurance and overall exercise performance. On the other hand, increasing sleep duration can enhance athletic ability: Stanford researchers found that basketball players who slept at least 10 hours per night improved accuracy, speed, reaction time and mental wellbeing.
Expert tip: Aim for daily physical activity—about 20 minutes or more—but avoid intense workouts within three hours of bedtime, which can energize the mind and delay sleep, Roban advises.
Sleep Helps Reduce Diabetes Risk
Short sleep duration is linked to a higher risk of type 2 diabetes. In one study, healthy young men limited to four hours of sleep per night for six nights developed signs of prediabetes; these symptoms improved after a week of extended sleep. A broad review of research suggests that seven to eight hours of sleep nightly is optimal for lowering diabetes risk.
Expert tip: Maintain consistent sleep and wake times and get daylight exposure during the day to reinforce your circadian rhythm, recommends Dr. Fran Walfish.
Sleep Strengthens the Immune System
Even modest sleep loss can impair immune function. A study that intentionally exposed participants to a cold virus found that people sleeping fewer than seven hours were nearly three times more likely to develop a cold than those sleeping eight hours or more. Quality sleep supports immune defenses and helps the body recover from infections.
Expert tip: Create a cool, dark sleeping environment—light suppresses melatonin, and a bedroom temperature between about 60 and 67°F supports restorative sleep, per the National Sleep Foundation.
Sleep Enhances Creative Problem-Solving
Research suggests that both non-REM and REM sleep phases contribute to creativity. During non-REM sleep the brain replays and consolidates memories, extracting general patterns; during REM sleep the brain explores connections between distant ideas. This tandem process helps isolate and then link concepts, boosting insight and creative problem-solving.
Expert tip: Reduce sodium at dinner and throughout the day to avoid fluid retention that can affect circulation and sleep, advises Colin Zhu, D.O.
Sleep Lowers Inflammation
Poor sleep is associated with higher levels of inflammatory markers and with inflammatory conditions such as inflammatory bowel disease. People who sleep six hours or less tend to have increased blood levels of proteins linked to inflammation, which is connected to diseases like heart disease, stroke, diabetes, arthritis and premature aging.
Expert tip: A calming bedtime routine can help; chamomile tea contains apigenin, an antioxidant that promotes relaxation, Walfish recommends.
Sleep Supports Mental Health
Sleep and mental health are closely connected. Many people with depression report poor sleep, and chronic insomnia raises the risk of developing depression. Studies of adolescents show that sleeping six hours or less increases the risk for major depression, which in turn can further disrupt sleep. Addressing sleep problems is often an important part of managing mental health conditions.
Expert tip: If you suspect depression or other mental health concerns, seek help from a physician or therapist—treating underlying issues can improve sleep quality and overall wellbeing.
Sleep Reduces Stress
Good sleep helps regulate cortisol, the hormone central to the body’s stress response. When you’re sleep-deprived, cortisol patterns become dysregulated, making it harder to respond effectively to everyday challenges and increasing emotional reactivity.
Expert tip: To lower stress before bed, practice breathing exercises, meditation, guided imagery or listen to slow, calming music, suggests Colin Zhu.
Sleep Enhances Brain Function
Sleep deprivation harms cognition, concentration and performance. In one study, medical interns working extended shifts made significantly more serious errors than those who had more sleep. Sleep disturbances in midlife and beyond are also associated with increased risk of later cognitive decline. Prioritizing uninterrupted sleep preserves attention, memory and decision-making skills.
Expert tip: Foods containing tryptophan—such as almonds, turkey and dairy—can have a calming effect. A warm cup of milk before bed may help promote relaxation, notes Dr. Walfish.
Sleep Improves Social Skills
Lack of sleep impairs the ability to read facial expressions and emotional cues, reducing empathy and emotional regulation. Sleep-deprived people are less accurate at recognizing anger, sadness and happiness, which can strain relationships and increase the likelihood of conflict.
Expert tip: Avoid alcohol close to bedtime. While it may initially induce drowsiness, alcohol interferes with sleep architecture and can prevent restful sleep, says Walfish.
Sleep May Contribute to a Longer Life
Both short and excessively long sleep durations are linked with higher mortality risk. Sleep may reflect overall health or be affected by diseases that also influence lifespan. For example, a British study found that fewer than five hours of sleep was associated with a substantially higher risk of death from cardiovascular disease. While research continues to clarify exact mechanisms, sufficient restorative sleep is a clear component of long-term physical and mental health.
Expert tip: Keep your weekday and weekend sleep schedules as consistent as possible—try to limit variations to about an hour. Large shifts in sleep timing on weekends can disrupt your circadian rhythm and make Monday mornings harder.
Want to sleep better and have more mental and physical energy when you are awake? Download Loóna, an award-winning sleep app that uses art, guided meditation, storytelling and science to help people unwind, relax and get more restful sleep.