4 Of the Most Important Reasons Why You Sleep

The most necessary inconvenience we have is that magical time each day when we disconnect from it all, lay our head on the pillow, and sleep. Are you having trouble sleeping? Waking up in the middle of the night? Are you not sleeping enough hours? Struggling at the gym? Well, read on my friend, because sleep in the right quality/quantity is vital to all of your performance. 

What is Sleep?

The sleep cycle is a complicated milieu of deep consciousness and altered sensory perception and muscle control. There are two basic types of sleep, REM (rapid eye movement) and non-REM sleep. Non-REM sleep is further divided into 3 stages.  

Stage 1 is typical once you close your eyes and may feel sudden jerking movements. 

Stage 2 involves the elimination of your eye movement, but you can still easily be woken up. 

Stage 3, which is deep in slow-wave sleep. Here vague dreams can occur, your heart rate and body temperature drop, and certain sleep disorders can appear.

REM sleep involves complete loss of muscle activity, eye movement, and brain function in an uncoordinated fashion. This is the stage where a vivid dreams and nightmares can occur.

Completion of this cycle takes 90 minutes on average and a good night of sleep will include 4-6 cycles (6-9 hours).

Your body coordinates this process via a combination of various inputs including melatonin (made in the brain), body temperature, stress hormones (cortisol), and light. The combination of these inputs can lead to the sleep timer, termed the circadian rhythm. 

Go to Bed Otherwise You Won’t Grow Up Big and Strong

When you were younger your parents likely said: “go to bed or you won’t grow big and strong.” Guess mom and dad were right. Generally speaking, we sleep to process portions of memory and rejuvenate the various process in the body. 

While sleeping you do experience a rapid increase in human growth hormone, which is important for…uh growth. As a kid there is debate if sleep actually leads to bigger humans, however, as an adult, this role is more linear. In adult men who experienced more slow-wave sleep had higher levels of growth hormone. Increased growth hormone has a direct relationship with increased muscle tone and mass and the opposite when low. So you won’t get taller necessarily, but you may get more from your gym performance without more exertion…yup!

On the subject of muscle, sleep also serves to regenerate your glycogen stores. Glycogen is vital to fueling your muscles during workouts. This carbohydrate is stored in low levels within the muscles and thus re-stocking the shelves is vital to the success of your workouts. 

If you have ever not eaten enough carbohydrates or slept enough, you may have noticed you sucked at your workout the following day. That is because you are operating heavy machinery on empty. Sleep and eat enough carbs and you shall power through those PRs.

The Sleep Recycling Plant

Sleep also acts as a recycling plant for your metabolic pathways which produce garbage. Metabolic pathways, act in the body like factories to process your nutrients and break down environmental exposures. Just like factories, they often will produce waste products called reactive oxygen species (ROS). These species can damage your DNA and lead to poor effects throughout the body including cancer. 

Not only do your metabolic factories decrease production during sleep leading to the production of less metabolic byproducts, but also your body is able to pick up the trash and get rid of ROS easier.

ROS is not the only byproduct that sleep recycles in the brain. Adenosine triphosphate or energy in the cells releases the phosphates to create energy and fuel your daily processes like digestion, walking, reading blogs, etc. When adenosine loses its phosphates, it builds up in the brain, binds to its receptor (like a key in a lock), and informs the brain of the amount used in the body. As you do more activities each day, you have more adenosine in the brain. Once the adenosine levels get too high, you have to get the adenosine out. Guess how that is done…yeah, sleep! Of note, caffeine works by preventing adenosine from binding to its receptor, therefore your brain cannot be aware of the high levels and need for sleep. More on that later.

Another vital breakdown product that is created in your body during the day is neurologic tangles. These protein tangles are the wasted products of bodily metabolism (above). The buildup in the brain and an increased number is associated with Alzheimer’s disease/dementia. Higher quality and quantities of sleep, in particular, slow-wave sleep, are associated with fewer tangles in the brain. Therefore, it is possible that sleep quality weighs into purging your brain of waste and potentially limiting the risk of dementia. 

Sleep to Digest the Day

Along the same lines of memory, another role sleep plays in our lives is with memory consolidation. Your brain utilizes a part called the hippocampus (remember a hippo never forgets). The hippocampus, during deep portions of sleep, takes your daily events, traumas, and activities and filters them into the hippocampus. This essentially forms your memory of the day’s events and your emotions associated with them.

Your subconscious way to deal with such memories during sleep is termed dreaming. Some believe there is strong relevance behind dreaming and your unrevealed desires (Freud), but this can be debated. Either way, you need adequate sleep quality and quantity to dream and you need proper sleep hygiene to have proper sleep.