We all know that getting enough sleep does wonders for how we feel. But few of us realise that during sleep, the body is doing more than resting – it’s working to restore our physical and mental wellbeing. Alongside other essential elements such as nutrition, hydration and meditation – sleep is the cornerstone of a balanced rest and recovery program – a fundamental requirement in achieving and sustaining musculoskeletal health and wellness.
We’ve all sacrificed sleep to fit more into our days. The immediate result is usually a blend of grogginess, grumpiness and irritability. If you continue to short-change yourself on sleep, you may experience further adverse affects on your brain’s ability to function in the short and longer term, such as:
Chronic sleep deprivation can also be a significant contributor to a range of serious medical issues including: high blood pressure, diabetes, heart attack, stroke, obesity, and psychiatric problems such as depression and other mood disorders.
So for those who brag that they can “get by” on just a few hours sleep, perhaps some insights about the science of sleep will reveal that sleeping is far from unproductive. Indeed, it’s a crucial component of a healthy, productive, and high quality life. And for those of you who long to improve your sleep experience – read on for helpful tips and strategies.
What does your body do while you’re asleep that is so important to health?
Sleep is divided into two categories: rapid eye movement (REM) and non-rapid eye movement (nREM). The first phase of sleep is nREM, and it splits into four stages, each stage deeper than the last, and each followed by a shorter REM phase. Every total cycle lasts approximately 90 minutes and these cycles repeat throughout the night and into the morning. The average person should aim to have 5 or 6 sleep cycles each night.
REM and nREM are necessary for optimal health but they have very different effects on the body. During nREM sleep the body is healing – regenerating tissue, building bone and muscle, and strengthening the immune system. During the REM cycle the brain rejuvenates, processing and consolidating experiences associated with memories, emotions and learning.
In January 2014, The New York Times described the brain as playing the part of “mental janitor” during sleep, clearing the mind of excess “rubbish” and flushing out toxins that build up during waking hours. Similar to toxins that build up in the muscles after a workout, the brain becomes saturated with information during a full day of thinking. This produces what some researchers believe to be toxic by-products that can often prevent further processing. So the old maxim – to “sleep on it” – before you respond to an emotional or difficult situation, may just have some science behind it.
And if you still feel groggy and unrefreshed after more than 7.5 hours of sleep, you may have awakened between a sleep cycle – essentially breaking the cycle. To help you bounce out of bed, you may want to plan your sleep to wake up at the end of a 90-minute cycle.
During sleep, the muscles in your body are at their most relaxed. This gives your body the chance to repair and rebuild your muscle tissue. Poor sleep can leave you sensitised to muscle overload from exercise or the postural stresses of life.
While you are sleeping and your body is immobile, your digestive system slows down dramatically. This allows the digestive system to rest and renew after converting food into the energy you need to go about your busy day.
Because the digestive system slows down so much during sleep, eating too much before bedtime will lead to that bloated feeling that might keep you awake and uncomfortable. Spicy and fatty foods can trigger acid production, which can flow back into the oesophagus and cause acid reflux/heartburn that will wake you up later in the night.
Alcohol is both a sedative and a stimulant, and too much alcohol or alcohol consumed too close to bedtime, interrupts the normal sleep cycle. Alcohol consumption causes the sleep cycle to be disrupted by jumping over the early sleep phase straight into deep sleep. As the alcohol metabolises (wears off) one reverts to the REM sleep where it is easier to wake up. Women metabolise alcohol more quickly than men, meaning they speed through the initial sedative effects of alcohol and typically wake up earlier or more frequently than men as a result.
When you are awake, your body is stimulated by hormones including adrenaline and natural corticosteroids which kick-start important processes. When you sleep, these hormone levels drop and your body starts to produce human growth hormone (HGH), which promotes growth, maintenance and repair of muscles and bones. During this process, every tissue in your body is renewed. Regular sleep will ensure that your body can regulate hormone production, helping you remain alert during the day and sleep well at night. Sleep also help regulates the hormones gherkin and leptin which help control feelings of hunger and fullness. When we are sleep-deprived, the production of these hormones is reduced and we may tend to eat more, potentially leading to weight gain.
There is science behind the adage “beauty sleep.” During the day your top layer of dead skin is shed. While you sleep the metabolic rate of your skin speeds up and new skin cells grow and replace older cells. This process is important for repairing damage from pollution and UV rays and rejuvenating your skin. A lack of sleep disrupts this renewal process. We all know that when you skimp on sleep it shows on your face.
During sleep your immune system releases certain agents that fight disease and help protect you from colds, flu and other ailments. Sleep deprivation suppresses the immune system, putting us at an increased risk of illness. When we are ill, we often feel an increased level of fatigue. This is the body’s way of encouraging you to get more sleep to enable your body to rest, fight the illness and sustain the battle.
Many studies have been conducted about the amount of sleep that is recommended for different age groups. Because we are unique in body composition, daily routine, genetic make-up and more, we have different needs for sleep. But certain principles can apply across the board.
Studies have shown that on average, the optimum amount of sleep for:
Sleep is highly beneficial for almost every part of your body and your mind. When you sleep, your body repairs itself, regulates vital processes and releases toxins so you can wake up feeling refreshed. With these restorative benefits in mind, be sure to get enough sleep. Your body, mind and overall state of wellness will thank you.
Source: Konnikova, Maria. “Goodnight. Sleep Clean.” The New York Times. The New York Times, 11 Jan. 2014. Web. 15 Dec. 2014.