Author: Subia Khan
How adequate sleep is, its timeliness and quality is as crucial as diet and workout. We know this now!
Part 1 of the article focused on how sleeping pattern is, how it is regulated, causes of sleep deprivation and measures to correct the same
Here we are continuing with even more critical insights..
How your various systems function while you are at rest and what are the repercussions of poor sleep on them. Obesity, hypertension and associated disorders, hormones etc. are so connected to How you sleep!
What your body does when you are resting. A must know!
Systems at work during sleep:
Our body has various systems performing their set of activities. A properly timed sleep ensures maintaining health of all our systems – nervous, circulatory, digestive, endocrine, respiratory and so on. Below mentioned summary indicates how systems function while human body is at rest.
1)Nervous System: The most essential component responsible for the complete body co-ordination is our central nervous system (CNS). Sleep aids all our cellular functions, cellular repair of all the vital organs / systems in body. Lack of sleep is a major cause for poor decision making, reduced activity of brain cells, poor memory coupled with reduced thinking power, situation handling and response mechanism. So next time you feel that you are tired, you have some headache or fatigue, you cannot put mind like you do every day; go back in time by a day or two and see how many hours you slept!
- Autonomic / Involuntary Nervous System – A Part of nervous system is responsible for functioning of muscles of the internal organs and glands. ANS regulates the processes which we cannot consciously dictate or get worked upon by choice. It is basically self-regulated.
Sympathetic nervous system works towards our physical and mental activity. It regulates heartbeat, aids respiratory system functions, suppresses digestion etc. The system is in full swing while the person is awake. Parasympathetic nervous system works for bodily functions at rest. It activates metabolism, stimulates digestion and relaxes mind.
A proper sleep is essential for healthy functioning of CNS and ANS.
2)Digestive System: Gastrointestinal system function slows down with the start of a slow wave sleep (NREM – our deep sleep cycle). On the other side REM witnesses a fastened gastric emptying state (Emptying food from stomach).
A)The digestive system requires energy to churn and metabolize food. Our system tried to save on this energy during the deep sleep hours and hence the salivation (producing saliva – the first step towards digesting carbohydrates), upper esophageal sphincter pressure (responsible for avoiding food reflux in pharynx) etc. are also reduced during sleep.
B)Studies also reveal dietary intake of a sleep deprived individual is on a higher calorie side resulting in increased BMI, fat percentage and finally obesity.
3)Endocrine System: Endocrine system has an adaptive mechanism with respect to our body’s sleep and wake-up pattern. It tends to reduce activity and energy consumption during sleep. It also governs our core body temperature, secretion of hormones like melatonin and cortisol etc. which play an important role for sleep.
A)A fall in core temperature towards night induces sleep and governs total sleep duration.
B)Melatonin – Secreted by pineal gland, melatonin is low during the day and rises during the night. It is responsible for promoting sleep. An anxiety prone / depressed individual may be having a reduced melatonin level which doesn’t help to trigger sleep in him and causes failure of rest period often creating more metabolic damage.
C)Cortisol – The stress hormone has its peak in the morning and fall during night. Cortisol levels are generally elevated in individuals who have sleep disturbances.
4)Immune System: Adequate sleep results in fighting infections and recovery at a better pace. Our capacity to remain healthy is affected by loss of sleep. A proper sleep maintains T-Helper (Th) cells in our body which helps in building a strong immunity by releasing antibodies to fight infections. This works in close connection with our neuroendocrine system (Responsible for secretion of Human Growth Hormone – HGH, Cortisol and Prolactin) which supports the natural process of immunity also.
Quality sleep also helps to rejuvenate our body, helps in cellular and tissue repair, aids absorption of nutrition; especially protein absorption leading to muscle growth. This happens through the release of HGH (Growth Hormone) while sleeping which enhances muscle growth and bone health. Hence it is an effective dietary strategy (based on fitness goals) to include pre-sleep protein in order to facilitate muscle protein synthesis (MPS) which in turn improves skeletal muscle’s response to strength training.
Repercussions of an Inadequate and Untimed Sleep:
With lack of sleep, our systems fail to perform as effectively as they should. Hence sleeping less than 6 – 8 hours per night on a regular basis can cause adverse health outcomes in adults:
- Endocrine System:
> Higher evening cortisol levels (Stress hormone).
> Reduced leptin levels (a hormone that regulates satiety, decreases appetite basically).
> Increased ghrelin levels (a hormone that regulates hunger, increases appetite basically).
- Nervous System: Alterations (Basically increased sympathetic nervous system activity which is majorly responsible for involuntary actions and fight-or-flight response.
- Weight gain / obesity: Nightmare of every individual eating quantified towards a fat loss goal! An un-regulated control of appetite due to reduced Leptin level and increased ghrelin leads to impaired signalling for caloric need of individual causing obesity. Sleep deprivation also causes a reduced NEAT, less physical activity and energy expenditure due to built-in fatigue and hence fat accumulation.
- Diabetes & Hypertension: While poor sleep results in obesity which itself is a reason for Type 2 Diabetes; fluctuations in HGH, Leptin, Gh, Cortisol etc. cause increased insulin resistance and reduced glucose tolerance resulting in accumulation in the form of fat over the time.
- Poor Cardiovascular health: Poor glucose intolerance, nutrient absorption and obesity can in turn lead to poor cardiovascular health. Choking of arteries because of fat accumulation might result in feeling of breathlessness and lack of stamina and endurance of an individual. Most of us know that extreme of choking arteries is a heart stroke!
- Poor nutrition absorption: Is it not scary to even think of this? Nutrients not reaching the cells responsible for giving you energy will eventually make them starve and die! Who will be responsible for vital functions then!
- Metabolic slow down: Metabolic damage for any of us; one wanting to loose fat or other wanting to build muscle is a total No-No! A system not given its due rest period will over the time perform poor (Think of your car not being serviced in its due time – How will the engine and mileage be?).
- An Impaired Immune System: Lack of sleep causes poor recovery and repair of our cells on a day to day basis. Over the time this causes poor immunity and decreased fighting ability of body towards infections.
- Depression and anxiety: Don’t give me food but let me sleep – most of us demand this. Quite obvious why!
So Let us go back to basics and revise the measures to ensure an adequate sleep:
- The more stable and consistent our circadian rhythm is, the better our sleep is. Hence sticking to a fixed routine helps getting quality sleep.
- Block your Clock: Sticking to a fixed sleep and wakeup time helps. With exception to occasions and contingencies, setting the clock for going to bed helps.
- Avoiding Caffeine, Alcohol and Nicotine, Smoke towards sleeping hours is highly recommended. (A) Caffeine can stay in system for hours affecting next day performance. It is easier to tame mind and go off to sleep after having a cup of coffee; however it is not possible to stop the systems churning once caffeine enters the system and generates stimulus. (B) Alcohol might generate a sedative effect initially; however it metabolizes during those sleeping hours thereby affecting the quality of sleep.
- Eat right: Every individual is aware of his system and how it responds. For e.g. If eating high protein or fat diet towards night causes reflux then it is wise to time the meals according to what best suits to the body.
- Free your mind: Psychological stressors and troubles should be side-lined while going to sleep. The switch to thinking cap and stress about next day has to be turned off.
- Meditation: A short meditation before going to sleep cools down the mind and brings positivity. This improves sleep quality.
And we never thought sleep to be so critical. Less or more than workout and nutrition is dependent on each of us, but sleep matters much more than we think it does!
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