Last week, I started explaining the importance of restful and sufficient night sleep. It is one of the very essential lifestyle habits that can be easily neglected due to the demands of modern-day jobs, which have become competitive, demanding long hours due to deadlines, taxing on the health of employees, managers, directors and CEOs. You can add college students to the list as well. To prove themselves, students and employees on the job are sleeping less, spending more late hours at work, and working even at home to meet deadlines, plus rising early to comply with company work hours. After a while, they start burning out and develop mental or even physical exhaustion and disorders (depression, diabetes, heart disease, cancers…). I shall address this aspect later in another part of this series.

Why did I choose to explore sleep in Ramadan? It is because during this month of fasting, people turn night into day, forgoing precious night sleep, which is vital to our psychological and physiological health and well-being.

In Part 1, I began discussing the circadian rhythm, our built-in biological clock, which tells us when to wake up, when to eat as it controls appetite, when to empty our bowels, when to rest, when to shut down, and when to sleep during the 24 hours of the day. This clock is dictated by bright daylight and the hormone, melatonin, which is secreted by the pituitary gland in the brain.

Now, I will continue describing this natural inner clock and its schedule and its influence on body functions, hour by hour, when sleep occurs at night, when the hormone melatonin is released, and when the hormone is suppressed, giving energy during daylight.

Here are how the body operates and when the brain releases certain hormones in order to trigger physiological functions. Darkness and time of sleep are key regulators of this biological clock.

After a good night sleep and just before dawn, the brain decreases the release of melatonin, which makes the body manifest certain physiological happenings in the following sequence, according to scientist Michel Siffre:

• At 6 a.m., the hormone, cortisol, becomes more elevated to stimulate both body and brain into action and also makes the blood pressure increase sharply.

• At 7 a.m., melatonin ceases to release, signaling the end of sleep and time to be active.

• At 8:30 a.m., the bowels start moving in people who enjoy regular bowel movement and eat regular meals.

• At 9 a.m., the body secretes its highest testosterone (sex hormone) for the day.

• At 10 a.m., mental alertness reaches its highest point and then levels down at noon, but this also depends if you are an early bird.

• At noontime, full bright daylight, energy decreases a little, signaling the need for a little rest, a siesta or a power nap (15 to 30 minutes).

• At 2:30 p.m., the body is at its best motor skills and coordination. It is a good time to go for a walk or any other physical activity.

• At 15:30 p.m., reflexes are at their best. Mental and physical responses are at their highest, making you alert for driving back home.

• At 5 p.m., the body is at its best cardiovascular efficiency and the muscles are at their peak of strength. Hit the gym!

• At 7 p.m., blood pressure and body temperature rise to their highest level for the day.

• At 9 p.m., as the body begins to slow down, melatonin gets released, preparing for bedtime. Mental and physical reactions decrease in speed.

• At 10 p.m., the digestive system quiets down and the bowel movement is suppressed to prepare the body for night rest.

• Around midnight with total darkness and quiet, the body and brain tired of a long exhausting day are ready for sleep.

• By 2 p.m., the deepest slumber takes over. Waking up can become a very difficult task.

• At 4 a.m., the body temperature drops at its lowest in 24 hours.

This is how a healthy daily schedule of sleep-wake cycle should work, which I simplified for you.

Now, I will elaborate on how night sleep occurs and explain its different phases and how they influence the body and brain. The quality of our sleep relies on our daylight schedule and energy expended. Our sleep cycle consists of two phases. They are the slow-wave sleep, which is the deep sleep we succumb to at the beginning of the night, and then comes the rapid eye movement (REM) sleep. Each phase leaves a different effect on our bodies and brains.

Slow-wave sleep overcomes the person and puts the body in a complete relaxation mode and deep sleep, when both body and brain are totally still. This happens after 16 to 18 minutes of going to bed, depending on the age of individual. In this phase of deep sleep, the body relaxes; breathing is regular; blood pressure falls; the brain is less reactive to the outside world; and arousal takes much more effort.

This sleep stage is crucial to health in order for the body to perform important functions that cannot be done during waking hours. They consist of the regeneration, healing, and repairing of cells, tissues, neurons, muscles, wounds, systems, organs, and other body and brain restorations and regulations. That is when the pituitary gland in the brain secretes the growth hormone, generating growth and tissue and muscle repair. This includes renewing energy and restoring the immune system.

This phase of sleep is essential for infants and children’s growth. Professional athletes require around 11 or 12 hours of night sleep to repair their bodies after hours of tough daily training. A Stanford study on basketball players found that players, who fulfilled these hours of sleep, performed significantly better and had more accurate free-throw shooting percentage and were faster in sprinting.

The harder one works physically the more sleep is needed. The better the quality of slow-wave sleep is, the more efficient the body is at repairing muscles and regenerating energy and immunity.

REM sleep, on the other hand, does to the brain what slow-wave sleep does to the body. During the slow-wave sleep phases, the brain remains rather quiet. However, with REM sleep, the brain becomes alive with activity. That is when dreams occur also. The brain at this phase sorts out information acquired during the day; does much of the reorganization; discards unimportant or unnecessary data; enhances the memory collected during the day and connects it with earlier events; reinforces the learning process; and develops neural growth and interconnection.

During REM sleep, the heartbeat increases; body temperature soars; and blood pressure elevates with the brain’s activity, while the body remains inert and unmoving. This type of sleep is not profound and happens from three to five times a night and does not last long.

When slow-wave and REM sleep stages do not occur, our cells begin to atrophy or mutate, because they are not given a chance to repair and regenerate. With sleep deprivation, the body starves; the immune defenses fall apart; repair does not occur; and the brain and mental abilities begin to fail. Sleep loss makes the body more susceptible to viral infections, gaining weight, diabetes, high blood pressure, heart disease, mental disorders and premature death.

While slow wave sleep is essential for physiological repair and recovery, REM sleep takes care of the brain, learning, mental growth, and memory reinforcement, making sleep quality paramount to physical health and mental wellbeing.

Next week, I shall talk about the effects of sleep deprivation on the body and brain.

References:

• The Science of Good Sleep: There is a reason You’re Always So Tired by James Clear in Wellness

N.B.:

Individuals with medical conditions or on medication should consult their physicians when they decide to introduce anything new in their diet even if it is natural.

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