How many hours of sleep do you get at night? If your answer is between seven and ten, then you’re probably doing pretty well! According to the National Sleep Foundation, the amount of sleep you need is dependent on your age. For teenagers between the ages of 14 and 17, the optimal amount of sleep is eight to ten hours. The amount of sleep needed for younger adults (18-25) and adults (26-64) is exactly the same, between seven to nine hours. For adults ages 65 and older, a slightly lower amount of seven to eight hours is needed to feel fully rested. These numbers make sense when you really think about. The younger you are, the more sleep you need to make it through the day.
Next you may ask, why do we need sleep? The answer is, there is no clear reason. Scientists have asked this question for years and there have been multiple studies done, but no one has come up with a clear result. There are, however, several theories as to why both humans and animals feel tired and require sleep. Two popular theories include the Restoration Theory and the Brain Plasticity Theory.
The Restoration Theory states that our body needs sleep in order to “restore” whatever it has lost throughout the day while being awake. While your body is sleeping, it takes the opportunity to “recharge” your batteries in a sense and restore functions like muscle growth, tissue repair, protein synthesis and releasing growth hormones. The Restoration Theory also mentions that sleep has proven to be important for cognitive function. The neurons in your brain produce adenosine, which has been linked to the cause of feeling tired. This may explain why you feel so tired after a long day of work and cognitive activity.
Another theory that has gained popularity is the Brain Plasticity Theory. This theory states that sleep plays a huge role in the structure and organization of the brain. This is especially critical for the brain development in infants and young children, which is why they need more sleep than adults. Studies have shown that a lack of sleep has an impact on the cognitive abilities of adults. For example, adults that did not have enough sleep had a harder time learning and performing other tasks, than those who got a good amount of sleep.
Although no theories have been proven, they have helped scientists get closer to fully understanding what causes us to sleep and why we need it.