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Sleep is a vital part of staying healthy — that’s why we spend about a third of our life sleeping. However, more than 60 percent of Americans say that their sleep needs aren’t met across the course of an average week. There are many things that can interfere with sleep, from children to stress to medications. In today’s blog post, ACRM is sharing some general information about the importance of sleep and its connection to brain health. Continue reading to learn more about this area of rehabilitation research and if you’re interested in networking with others in the field of rehabilitation medicine, contact us today.

Why Do We Sleep?

Although scientists aren’t entirely sure why we sleep, there are many theories for why we sleep. One of the earliest theories of sleep, called the inactivity theory, suggests that sleep served the purpose of keeping vulnerable organisms from being killed by predators during the dark. Another theory, called the energy conservation theory, suggests that the purpose of sleep is to reduce an organism’s energy demand when there is less food around. 

Other explanations for why we sleep fall under the umbrella of restorative theories. These theories suggest that the purpose of sleep is to restore what is lost in the body when we are awake. Sleep deprivation can kill you, and restorative functions like muscle growth and tissue repair occur when sleeping.

Sleep And The Brain

Other restorative theories for sleep focus on sleep and the brain. When we sleep, the brain can clear adenosine, a by-product of neuron activity during the day. Clearing adenosine can help us feel more alert when we wake. 

One of the more compelling recent areas of study into sleep is called the brain plasticity theory. Studies have shown that sleep is correlated to changes in the structure and organization of the brain. This could be one of the reasons why infants spend so much time sleeping — their brain is developing while they sleep. The link between brain plasticity and sleep is also becoming more clear in adults, and it is an exciting area of rehabilitation research. 


The connection between sleep and learning is not entirely understood, but we do know that healthy sleep is essential for optimal learning and memory function. Evidence suggests that the different sleep stages are involved in the different types of memories that are stored in the brain. These types of memory include declarative memory (fact recall) and procedural memory (how to do something). Evidence also shows that being sleep deprived reduces your ability to learn and remember.

How Much Sleep Do You Need?

The need for sleep changes over a lifetime, and also varies across individuals of the same age. Babies sleep around 16 to 18 hours a day, while school-age children need about 9.6 hours per night. Adults should shoot for 7-9 hours of sleep a night, until around age 60, when nighttime sleep is lighter and often interrupted. Seniors are more likely than other age groups to take medications that interfere with their ability to sleep, and this may be one of the reasons why that age group has less restful sleep during the night.

Can You Catch Up On Sleep?

Many people think that if they have a hard, stressful week and don’t get good rest, they can just “catch up on sleep” over the weekend. However, sleeping doesn’t work that way. It’s nearly impossible to catch up on sleep after sleep deprivation. Experts call the load of sleep you’ve missed “sleep debt” and it is the difference between the amount of sleep you should be getting and the amount you actually get. 

This debt accumulates every night that you sleep less than you need. You can repay that debt, though, by setting a more regular sleep routine. Start by going to bed when you are tired and allowing your body to wake you up in the morning (without an alarm). You may need 10hours of sleep or more until your body readjusts and restores, but after you’re back to a regular schedule, the amount of time that you need to spend sleeping will decrease. 

ACRM – American Congress of Rehabilitation Medicine

The mission of our non-profit organization is to improve the lives of disabled people through rehabilitation medicine and research. Our research groups cover a wide range of topics, from brain injury to neuroplasticity, cancer, and more. There is always something new happening in the field of rehabilitation research, and we’re excited about the questions currently being explored in are of sleep and brain health.

We work with hospitals, universities, professional and advocacy organizations, and rehabilitation professionals around the world. We have 3,000+ members from more than 65 countries and produce the ACRM Journal. Learn about the benefits of joining ACRM as well as member dues and how to apply. If you enjoyed this article, consider joining our Neuroplasticity Networking Group.