You need 8 hours of regular sleep every night, and here’s why
Getting regular sleep is one of the most underrated things, and it's more important than you might think. A CDC study found that more than one-third of American adults aren't getting regular sleep on a daily basis.
Failing to get proper rest has been linked to obesity, heart disease, mood disorders and impaired concentration and decision-making.
Sleep and Health
Regular sleep is crucial for overall health and well-being. Numerous studies have demonstrated that adults who consistently get 7-9 hours of sleep every night have improved cardiovascular health, more robust immune function, better metabolism and weight control. It also helps reduce the risk of diabetes, stroke, and heart disease compared to those who regularly get insufficient sleep.
For example, a large study published in the European Heart Journal followed over 21,000 adults, aged 42-81, for 25 years. It found that those who struggled with insomnia and failed to get adequate sleep were 27 percent more likely to develop cardiovascular disease. The researchers concluded that poor sleep is an important risk factor for heart health.
Other research has linked regular sufficient sleep to lower blood pressure, healthier cholesterol levels, and moderate stress hormone levels like cortisol. One reason is that growth hormone is primarily secreted during deep sleep phases. This growth hormone plays a key role in repairing blood vessel damage that occurs each day.
Skimping on sleep reduces growth hormone release, resulting in elevated stress on the cardiovascular system over time.
On the immunity front, research has shown that well-rested individuals have a more vigorous immune response to viruses and vaccines compared to those who lack sleep.
For example, a study vaccinated healthy adults against the flu virus. Those who slept less than seven hours per night had just half the immune response of those getting eight or more hours of sleep. The researchers theorized that without enough sleep, the body doesn’t produce sufficient cytokines and other compounds needed for an optimal immune reaction.
Sleep and Mental Health
Sleep is crucial for our mental health and cognitive functioning. Numerous studies have shown that adequate sleep improves mood, cognitive function, and memory.
When we don't get regular sleep, it impairs our ability to regulate emotions and process information. Sleep deprivation leads to increased anxiety, irritability, and heightened emotional reactions. Lack of sleep also makes it more difficult to concentrate, retain information, and perform tasks that require critical thinking or creativity.
Research has consistently found that poor sleep is associated with lower life satisfaction and a higher risk of depression. One study found that insomnia doubled a person's risk of developing depression within the next year.
Other studies show that treating sleep problems can help alleviate symptoms of anxiety and depression. This is likely because quality sleep facilitates emotional regulation and allows the brain to process emotions from the previous day.
Sleep is also vital for memory consolidation and cognitive function. During sleep, the brain shifts memories from short-term storage to long-term storage. Not getting enough sleep impedes this process, which is why trying to retain new information after a poor night's sleep is very difficult.
Multiple studies have shown that memory is boosted by getting at least 7-8 hours of sleep each night.
Sleep and Productivity
Studies have shown that adequate sleep improves productivity and performance in the workplace and in academics. Research from the Division of Sleep Medicine at Harvard Medical School found that workers who got less than 6 hours of sleep a night had significantly lower productivity, performance, and safety outcomes compared to those who got 7-8 hours of sleep.
Sleep-deprived individuals made more errors, had slower response times, and lower motivation on tasks.
In academics, studies have demonstrated that later school start times allowing teens to get more regular sleep resulted in improvements in grades, standardized test scores, attendance, and graduation rates. Researchers believe that with sufficient sleep, students are more focused and better able to retain information from studying and classes.
Well-rested individuals have also demonstrated greater creativity and innovation in studies. Getting regular sleep helps the brain make connections between ideas and solve problems more effectively. When you are tired, it's much harder to think creatively or come up with innovative solutions.
How Much Hours of Regular Sleep Do We Need?
Sleep experts recommend different amounts of sleep for different age groups:
- Newborns (0-3 months): 14-17 hours
- Infants (4-11 months): 12-15 hours
- Toddlers (1-2 years): 11-14 hours
- Preschoolers (3-5 years): 10-13 hours
- School-age children (6-13 years): 9-11 hours
- Teenagers (14-17 years): 8-10 hours
- Adults (18-64 years): 7-9 hours
- Older Adults (65+ years): 7-8 hours
The recommended amount of regular sleep for healthy adults is at least 7 hours per night. Getting less than seven hours on a regular basis can lead to health problems over time.
Some people claim to feel well-rested on just 5 or 6 hours of sleep. However, research suggests that people who believe they are getting enough sleep with such little sleep duration may still have impaired judgment and cognitive functions.
Creating a regular sleep routine by going to bed and waking up at the same time each day can help regulate your body's circadian rhythm so you fall asleep more easily.
Avoiding blue light exposure, limiting caffeine intake, keeping your bedroom cool and dark, and doing relaxing activities before bed also promote better sleep. If you continue having trouble getting regular sleep, it may be worthwhile to seek medical advice to identify and address any underlying issues.