What are the Four Stages of Sleep?

A person will go through four stages of sleep as they are sleeping at night. Each sleep stage has a specific function and responsibility to restore and maintain your brain’s overall cognitive performance. The first three stages of sleep are considered non-rapid eye movement (NREM) sleep, and the fourth is referred to as rapid eye movement (REM) sleep.

Why Do We Need Sleep?

There are many reasons we need sleep, including:

• Energy conservation: Sleeping helps to conserve energy and reduces our caloric needs because our bodies function at a lower energy as they are sleep.

• Cellular restoration: Sleep allows cells to repair and grow. Processes, like muscle repair, protein synthesis, tissue growth, and hormone release, all occur as a person is sleeping.

• Brain function: Sleeping helps the brain to reorganize its nerve cells, clearing our waste from the central nervous system. While asleep, your brain’s glymphatic system removes toxic byproducts and other buildup, resulting in a well-working brain when a person wakes up the next day. Functions of the brain that are positively affected by sleep are learning, memory, problem-solving skills, decision-making, focus, and more.

• Immunity: Sleep contributes to a healthy and strong immune system. While asleep, the body makes proteins that fight infections, which is why sleep is so critical when a person is sick.

• Weight maintenance: Sleep controls a person’s hunger hormones like ghrelin (which increases appetite) and leptin (which increases the feeling of being full after eating). Lack of sleep imbalances these hormones, and can cause a person to eat more calories and gain weight.

• Emotional well-being: During sleep, brain activity increases in areas that regulate emotion. This helps a person to react responsibly to a number of events that can happen throughout the day.

• Proper insulin function: Insulin is a hormone in the body that helps your cells use glucose (sugar) for energy. If your body doesn’t produce the proper amount of insulin, it may result in high blood glucose levels and perhaps Type 2 Diabetes.

What is a Sleep Cycle?

A sleep cycle is a process that involves both NREM and REM sleep. This cycle repeats every 80 to 100 minutes, resulting in 4-6 cycles per night depending on how much sleep a person gets.

What Happens If You Don’t Get Enough Sleep?

Sleep deprivation can have many short and long-term effects on the body. Sleep deprivation can increase the risk of mental health disorders (like depression and anxiety), make you feel tired and unfocused during the day, increase your risk of chronic health problems (like heart disease, diabetes, stroke, obesity, and more), and decrease your overall quality of life.

How Much Sleep Do You Need?

Tips for a Healthier Sleep Cycle

Establish a bedtime routine. A bedtime routine includes doing the same few activities before bed and creating a routine for yourself that lets your brain and body know it is time to wind down and fall asleep. Close your curtains, put pajamas on, brush your teeth, and more are all great low-energy options to do to get ready for bed.

Avoid alcohol at night. Alcohol is a stimulant that can prohibit you from falling asleep and also may negatively your sleep cycle during the night.

Exercise regularly. Getting regular exercise can improve sleep and health because it uses some of your body’s energy, resulting in falling asleep faster. Exercise 3-4 times a week, not too close to bedtime, to see the optimal results.

Reduce blue light exposure. Blue light is emitted from electronic screens and can keep you awake at night. Turn off your TV, put down your smartphone or laptop, and find new ways to relax yourself at night.

Relax and clear your mind. Practicing relation techniques, like doing yoga, taking melatonin, or reading a book, will help your mind get used to knowing that it is time to wind down and soon fall asleep. These types of practices have been proven to improve sleep quality.