Quality sleep is one of the most fundamental nutrients that every person needs in order to perform at their optimal. Sleep deprivation creates a heightened stress response within the body that disrupts normal healing and tissue rejuvenation processes. Sleep deprivation increases allostatic load on the body and rapidly accelerates the aging processes.
The term allostatic load was originally developed by Stellar and McEwan in 1993. It is defined as the physiological consequences of chronic exposure to fluctuating or heightened neural or neuroendocrine responses that result from repeated or chronic stress. Frequent activation of the body`s natural stress response, essential for adapting to acute survival threats, can damage the body in the long run. The higher the allostatic load an individual experiences the greater the toll on the body. Higher allostatic load increases the risk for sickness, injury, disease and early mortality. Healthy sleep cycles help to reduce allostatic load and allow individuals to adapt to life`s stressors more effectively.
Sleep Deprivation and Your Hormones:
Sleep deprivation is something that most people encounter at some point in their life. This process enhances the activity of the hypothalamic-pituitary-adrenal axis, which controls the stress response while regulating digestion, immunity, mood, cognitive function, and energy usage. This increases stress hormone release, which is counterproductive to healing. Sleep deprivation initially causes elevated cortisol and norepinephrine levels. As this progresses, the adrenals burn-out and stress hormone production is reduced.
Sleep deprivation dramatically reduces human growth hormone secretion and testosterone production. Both of these hormones are responsible for tissue healing and boosting metabolism to burn fat and build muscle as well as for providing a healthy immune response. Sleep deprivation causes a decrease in lean body tissue, an increase in fat storage and decreased immune coordination. Lowered immune coordination increases inflammatory processes and increases the susceptibility to auto-immune conditions.
Sleep Loss and Your Metabolism:
Sleep loss has a dramatic effect on energy homeostasis. Researchers have found that a reduction of sleep to 4 hours for 2 consecutive nights decreased circulating leptin levels and increased ghrelin levels as well as self-reported hunger. Leptin is our satiety hormone that signals to our body that we are satisfied and alters our metabolism to burn fat. Ghrelin is our hunger hormone that enhances feelings of hunger. Similar findings have been found in just one night of reduced sleep.
Sleep deprivation also reduces insulin receptor sensitivity leading to increased susceptibility to diabetes type II. Sleep deprivation also dramatically increases the risk of heart disease, cancer, and overall mortality.
In athletes, sleep deprivation reduces glycogen synthesis in skeletal muscle and liver cells. Additionally, it reduces cellular anti-oxidant status and bicarbonate formation. This process affects the athletes’ available energy stores during anaerobic exercise and limits the ability to buffer the metabolic byproducts involved in intense training.
Sleep Deprivation and Your Brain:
Sleep deprivation dramatically affects brain and cognitive function. In a study performed by the USCD School of Medicine, regions of the brain`s prefrontal cortex displayed enhanced activity in sleep deprived individuals during simple verbal tasks. This processing showed a decreased processing efficiency. It was hypothesized that the brain was compensating for reduced neural coordination with increased metabolic activity.
“We know that sleep loss is going to create significant detriments in performance,” says president of Alertness Solutions and a former NASA scientist, Mark Rosekind, PhD. “There are lab studies that show that if you’re an eight-hour sleeper and you get six hours of sleep, that two-hour difference can impact your performance so that it equates to how you would perform if you had a 0.05 blood-alcohol level.”Memory performance has been shown to be significantly reduced in sleep deprived individuals. Coordination, balance and reaction time are also known to be reduced in chronically sleep deprived individuals.
Sleep Deprivation and Your Memory:
Memory performance has been shown to be significantly reduced in sleep deprived individuals. This is due to the excessive release of the neurotransmitter GABA. GABA has an inhibitory effect on neuronal structures. Elevated GABA levels inhibit the body from forming new memories effectively. Coordination, balance and reaction time are also known to be reduced in chronically sleep deprived individuals.
A 2002 University of California study demonstrated that non-rapid eye movement sleep (NREM) is necessary for turning off neurotransmitters. This process allows the receptors to recharge and improves receptor sensitivity. The monoamines (norepinephrine, serotonin and histamine) depend on this process to function effectively. This natural process leads to improved mood regulation and increased learning ability.
Effective sleep recovery depends upon the period of time in which the sleep deprivation has occurred. Cognitive and endocrine function is recovered more rapidly after acute total sleep deprivation than after chronic sleep restriction. One night of recovery sleep can reverse adverse effects of total sleep deprivation. Recovery sleep has shorter sleep latency & increased amounts of deep & REM sleep.
Sources For This Article Include:
Schmid SM, Hallschmid M, Jauch-Chara K, Born J, Schultes B. A single night of sleep deprivation increases ghrelin levels and feelings of hunger in normal-weight healthy men. J Sleep Res. 2008 Sep: 17(3):331-4.
Hatfield, Heather. “How to Sleep Like an Olympic Athlete.” WebMD. Jan 1st, 2007