Sleep deprivation also reduces attention, focus, and concentration, making problem solving and learning more difficult. In the gym, lack of sleep impacts our strength, speed, reaction time, muscle recovery, chance of injury, focus, and teamwork.
All of these impairments will improve after one good night of sleep, however for a more complete recovery it will likely take several nights.
Drowsy Driving and Workplace Accidents
Driving when drowsy leads to slow reaction times and reduced awareness, making driving incredibly dangerous. 1 in 6 crashes in the UK that are either fatal or cause serious injury are due to fatigue, and certain times of the day are most associated with fatigue-related crashes: 02.00-06.00 and 14.00-16.00.
A large proportion of all serious car crash injuries are associated with driver sleepiness. For the majority of us who need 7-9 hours of sleep a night, sleeping for only six hours for 10-12 days can result in the same degree of cognitive and motor impairment as a blood alcohol level (BAC) of 0.08, which is considered legally drunk. The same level of impairment may be present when achieving only four to five hours of sleep for one week, or by going a full night without sleep. While we may not realise it, drowsy driving is similar to intoxicated driving in terms of our level of impairment, yet many people never hesitate to drive their children and loved ones when tired.
Sleep deprivation also impacts our ability to avoid workplace accidents. Highly fatigued workers are far more likely to be involved in accidents than workers with low fatigue levels.
Calorie Intake
People who don’t get enough sleep also experience hormonal disturbances that affect body weight. Lack of sleep leaves us craving more energy in a hope to boost energy levels and feel more alert, and often it is sugary snacks that we reach for as they provide a quick fix of energy. They only provide a short term energy boost though, blood sugar levels will spike and then reduce again shortly, leaving us craving energy once again, leading us into a vicious cycle that if exposed to over time will result in weight gain.
Similarly when we are tired our brain can struggle to distinguish between feelings of tiredness and hunger, often leading us to believe that we are hungry, therefore it is important to take a step back and think 'am I really hungry? Does my body need more food?', as it may just be tiredness.
Emotional Intelligence, Judgement, and Relationships
Inadequate sleep results in a worsened ability to accurately read other people’s facial expressions, among other cues key to our emotional intelligence. People who are sleep deprived tend to view others as more threatening than someone who is not sleep deprived. Sleep deprivation also makes it harder to control and appropriately express emotions. Having more difficulty making decisions about right versus wrong is another side effect of insufficient sleep. Similar to alcohol intoxication, we become less aware of our own impairment the more sleep deprived we become. Given that lack of sleep is linked to poor decision making, less humour and positivity and a reduced ability to solve problems, it is not surprising that sleep deprivation negatively impacts the ability to create or maintain healthy relationships.
Immune System and Recovery
The body’s immune system relies upon good sleep in order to function properly. Sleep deprivation is linked to an increased risk of cold and flu. Cold symptoms may linger longer when sleep deprived. Lack of sleep is also tied to longer times for vaccines to become effective. When sleep deprived, the body takes longer to recover from general body soreness and muscle repair as well as from injuries and major illnesses because energy is being diverted to keeping us awake as opposed to being focused on our immune system.
Sex Drive and Fertility
Research has shown that lack of sleep, even in the short term, leads to significantly decreased testosterone levels for men. A similar effect on libido has also been found in women. Research also suggests that lack of sleep can negatively impact our reproductive hormones, thus having an negative impact on our fertility levels.
References;
http://www.cdc.gov/features/dssleep/
http://www.today.com/health/5-sleep-myths-are-making-you-more-tired-1C9422113
https://sleepfoundation.org/sleep-topics/drowsy-driving
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1739867/
http://ajcn.nutrition.org/content/early/2014/06/25/ajcn.114.086579
http://www.ncbi.nlm.nih.gov/books/NBK19958/
http://www.webmd.com/sleep-disorders/excessive-sleepiness-10/relationships
http://www.huffingtonpost.com/dr-michael-j-breus/sleep-linked-to-infertili_b_260367.html
Article written by Optisum