Next time you "oversleep" after a hard mental or physical day, rather than give in to unnecessary guilt, realise your body knows best. Photo / Getty Images
Next time you "oversleep" after a hard mental or physical day, rather than give in to unnecessary guilt, realise your body knows best. Photo / Getty Images
Every one of us, male or female, young or old, is allotted 24 hours each day. Some of this time is spent in a waking state, consciously active, while about one-third is spent in an "inactive" sleep state. Or is it?
Before 1950, most people believed the brain and bodyto be completely dormant during sleep time because the prevailing belief was that "sleep was a passive activity". However, ongoing studies proved this weak theory wrong as scientists and researchers continue to reveal something entirely different - that both our brain and our body stay remarkably active while we sleep.
Furthermore, neurologist and sleep expert Mark Wu, MD, PhD, along with fellow researchers from Johns Hopkins University, discovered that "sleep is not only a period during which the brain is engaged in a number of activities necessary to life – but that these specific activities are also closely linked to the quality of life".
The reality is, nearly all systems in the body and every type of tissue (including our brains, hearts, and lungs) is either positively affected by quality sleep or negatively affected by lack of it.
Chronic lack of sleep compromises our immunity, putting our health at risk. Basically, we become sitting ducks for illness and disease and common disorders such as obesity, cardiovascular disease, high blood pressure, diabetes, and depression are all given the upper hand.
Here are a few amazing things that our brain and our body experiences when sleeping:
• Brain activity – Sleep is the perfect time for the neurons in the brain to go to work reviewing, sorting, filing, and storing information gained during the day.
• Hormonal activity/release – Hormones are chemical messengers and many of them are replenished and/or released into the bloodstream during sleep. Some of them are released in the brain and others in the body.
• Melatonin – As darkness settles in, this hormone, produced in the brain, is released and is responsible for giving the body the signal to sleep. It is best to eliminate as much bright light as possible at bedtime because light can seriously affect or even stop the release of this "sleep" hormone.
Chronic lack of sleep compromises our immunity, putting our health at risk. Photo / 123rf
• Oxytocin – Produced in the hypothalamus (base of the brain) and involved with lactation, childbirth, and social interaction/behaviour. Levels of this hormone may influence dreams.
• Growth hormone – A major hormone, essential for tissue growth and repair.
• Ghrelin and leptin – Leptin, the hormone released in the body that helps regulate body weight by inhibiting hunger. Quality sleep balances our appetite by maintaining healthy levels of these two essential hormones released at night.
• Insulin and cortisol – Sleep also controls the hormonal levels of insulin and cortisol released so our bodies use insulin correctly and when we wake, our appetite naturally prompts us to eat breakfast. We also experience optimal energy and increased immunity with the fortitude and strength to face the day's challenges.
• Prolactin – Produced in the brain/pituitary gland and related to and involved with over 300 body functions including metabolism and immune system regulation. Lack of quality sleep for extended periods of time can throw levels of this hormone out of balance, damaging and weakening our immune system, making it harder to concentrate during the day and ramping up carbohydrate cravings (adding to an already difficult time losing weight!)
There are other hormones produced in the brain such as ADH (antidiuretic) that affect urine production. Women and men both have their own specific issues with hormones as well. Women with premenstrual symptoms can experience reduced levels of melatonin (and other hormonal issues) causing poor sleep, night-time restlessness and waking along with daytime sleepiness.
Men, whose major hormonal player is testosterone, experience their highest levels of testosterone during sleep, but it requires at least three consecutive hours to reach this peak. Lack of sleep or sleep deprivation, ageing and other physical problems result in low levels of testosterone. In other words, sleep affects the production of testosterone and the production of it affects sleep!
Sleep is personal and the amount required by us changes as we age, so it is important to understand there is no perfect "number of hours" of sleep that works for everyone. Babies going through active growth and development sleep the most, requiring as much as 18 hours daily, while children and teens come in about 9-10 hours daily and adults at 7-9 hours of sleep per 24 hours. Those over 60 require shorter periods of sleep that is lighter and often interrupted by waking.
Without a doubt, sleep is a dynamic yet complex process vital for both mental and physical health. Our metabolism, disease resistance and even our moods and productivity all depend on quality sleep. Lucky for us, the body has mechanisms in place that automatically alert us when we need it.
It seems honouring, developing, and fostering a good sleep routine is the real key to experiencing mental clarity, physical balance and productivity and the warm, contented feeling of success and happiness we crave when awake.
Next time you "oversleep" after a hard mental or physical day, rather than give in to unnecessary guilt, realise your body knows best and has earned this time for rejuvenation, growth and repair and enjoy it! Sleep – "it does a body and a brain good!"
