In an article headlined The Arrogance of Ignoring Our Need for Sleep leading scientists have warned of the supreme arrogance of trying to do without sufficient sleep.  We are sleeping between one and two hours less per night than people did 60 or so years ago and it’s having a devastating impact upon every part of our lives.

Over the last few months I’ve been collecting research about the dangers of too little sleep, which I’ve summarized below. Once you’ve read that, you’ll probably want to pre-order Adrian Reynolds’ much-needed new book: And So to Bed: A Biblical View of Sleep (might be the best $6 you’ve spent this year!). Also check out 10 Reasons Why We’re Sleeping So Badly.

Physical Consequences

  • Just one week of sleeping fewer than six hours a night results in changes to more than 700 genes.
  • Just one night of sleep deprivation is linked with signs of brain tissue loss.
  • Infection-fighting antibodies and cells are reduced during periods when we don’t get enough sleep.
  • Sleeping fewer than seven hours a night is associated with a tripled risk of coming down with a cold.
  • Sleep loss increases hunger, portion size, and preference for high-calorie, high-carb foods, with the resulting risk of obesity.
  • Chronic sleep deprivation (less than 6 hours a night) is associated with:
    • Skin aging
    • 4 x stroke risk for middle- and older-aged people
    • 50% higher risk of colorectal cancers, and some links with other cancers too
    • High blood pressure
    • 48% higher chance of developing or dying from heart disease
    • Lower fertility rates.

Sport Consequences

More and more elite athletes are increasing sleep and even hiring sleep coaches in order to improve performance. The reasons are obvious

  • Chronic sleep loss can lead to a 30-40% reduction in glucose metabolism.
  • Sleep loss means a 11% reduction in time to exhaustion.
  • 2 days of sleep restriction can lead to 3x increase in lapses of attention and reactivity.
  • Maximum bench press drops 20 lbs after 4 days of restricted sleep.
  • Rested tennis players get a 42% boost in hitting accuracy during depth drills.
  • Sleep improves split-second decision-making ability by 4.3%.
  • Sleep extension provides swimmers a 17% improvement in reaction time off the starting block.
  • Football players drop 0.1 s off their 40-yard dash times by sleeping more.

This isn’t just a theory – consider the average sleep time of top athletes: Roger Federer: 11-12 hours per night; Usain Bolt: 8-10 h; Lebron James: 12 h; Michelle Wie: 10-12 h; Rafael Nadal: 8-9 h; Tiger Woods: 4-5 h (might explain a lot!)

Athlete Quotes

  • I think sleep is just as important as diet and exercise (Grant Hill)
  • Sleep is half my training (Jarrod Shoemaker)
  • If I don’t sleep 11-12 hours a day, it’s not right (Roger Federer)
  • A well-rested body is a healthier, more efficient, more capable one. This could be the hardest thing to accomplish on my to-do list, but it always makes a difference (Kerri Walsh).
  • Sleep is extremely important to me – I need to rest and recover in order for the training I do to be absorbed by my body (Usain Bolt).

Intellectual Consequences

  • Sleep flushes dangerous proteins from your brain, improving mental health. “When you’re sleep deprived, you get a dirty brain.”
  • Sleep allows the brain to consolidate and store the day’s memories.
  • Being exhausted zaps your focus, and can render you more forgetful.
  • Chronic sleep deprivation in adolescents diminishes the brain’s ability to learn new information,

Emotional Consequences

  • Sleep loss produces apathy, irritability, weepiness, impatience, anger, flattened responses.
  • Sleep loss can cause psychological damage because sleep regulates the brain’s flow of epinephrine, dopamine, and serotonin, chemicals closely associated with mood and behavior.
  • People with insomnia are 10x as likely to develop depression and 17x as likely to have significant anxiety.
  • The lack of sleep affects the teenage brain in similar ways to the adult brain, only more so. and can lead to emotional issues like depression and aggression.
  • In one study by researchers at Columbia University, teens who went to bed at 10 p.m. or earlier were less likely to suffer from depression or suicidal thoughts than those who regularly stayed awake well after midnight.

Societal Consequences

Getting sleep is an act of loving your neighbor by keeping the 6th commandment.

  • Sleep is increasingly recognized as important to public health, with sleep insufficiency linked to motor vehicle crashes, industrial disasters, and medical and other occupational errors.
  • Getting six or fewer hours of sleep triples your risk of drowsy driving-related accidents.
  • Just one bad night’s sleep can affect a driver’s eye-steering coordination.
  • The Cognitive Impairment that results from being awake for 24 hours is higher than the drunk drive limit in all states.
  • According to the NHSA, falling asleep while driving is responsible for at least 100,000 crashes, 71,000 injuries and 1,550 deaths each year in the United States.
  • Young people in their teens and twenties are involved in more than half of the fall-asleep crashes on the nation’s highways each year.
  • The Exxon Valdez, Challenger Space Shuttle, and Metro North Train tragedies in New York were all linked to sleep-deprivation.

Financial Consequences

  • Undermines creativity, problem-solving ability, and productivity.
  • Estimated to cost American businesses $63 billion a year.
  • The worst costs arise from the fact that sleep deprivation causes safety lapses and contributes to other health issues.
  • Other people (customers/clients) are likely to register a sleep-deprived person as lacking energy and unhealthy.
  • 32 billion dollars a year spent on meds, mattresses, candles, sleep consultants, etc.

Educational Consequence

  • 60 percent of grade school and high school children report that they are tired during the daytime and 15 percent of them admitting to falling asleep in class.
  • Sleep deprivation is such a serious disruption that lessons have to be pitched at a lower level to accommodate sleep-starved learners.
  • The United States has the highest number of sleep-deprived students, with 73% of 9 and 10-year-olds and 80% of 13 and 14-year-olds identified by their teachers as being adversely affected.
  • In literacy tests 76% of 9 and 10-year-olds were lacking sleep.
  • Children who have more sleep achieve higher in maths, science and reading.

Moral Consequences

  • A lack of sleep robs the fuel for self-control from the region of the brain responsible for self-control, whereas sleep restores it.
  • Studies found that a lack of sleep led to high levels of unethical behavior.
  • In tests, there was a difference of only about 22 minutes of sleep between those who cheated and those who did not.
  • A lack of sleep leads to deviant behavior at work (like falsifying receipts), similarly because of decrements in self-control.

In The Gulag Archipelago, Alexander Solzhenitsyn lists sleeplessness as one of 31 methods that his captors used to break a prisoner’s will. He wrote: “Sleeplessness befogs the reason, undermines the will, and the human being ceases to be himself, to be his own ‘I,’”

Spiritual Consequences

D.A. Carson wrote:

Doubt may be fostered by sleep deprivation. If you keep burning the candle at both ends, sooner or later you will indulge in more and more mean cynicism—and the line between cynicism and doubt is a very thin one….If you are among those who become nasty, cynical, or even full of doubt when you are missing your sleep, you are morally obligated to try to get the sleep you need. We are whole, complicated beings; our physical existence is tied to our spiritual well-being, to our mental outlook, to our relationships with others, including our relationship with God. Sometimes the godliest thing you can do in the universe is get a good night’s sleep—not pray all night, but sleep. I’m certainly not denying that there may be a place for praying all night; I’m merely insisting that in the normal course of things, spiritual discipline obligates you get the sleep your body need. (Scandalous, 147)

Ministry Consequences

An aside from John Piper’s 1995 lecture on Charles Spurgeon:

A personal word to you younger men. I am finishing my 15th year at Bethlehem and I just celebrated my 49th birthday. I have watched my body and my soul with some care over these years and noticed some changes. They are partly owing to changing circumstances, but much is owning to a changing constitution. One, I cannot eat as much without gaining unhelpful weight. My body does not metabolize the same way it used to.

Another is that I am emotionally less resilient when I lose sleep. There were early days when I would work without regard to sleep and feel energized and motivated. In the last seven or eight years my threshold for despondency is much lower. For me, adequate sleep is not a mater of staying healthy. It is a matter of staying in the ministry. It is irrational that my future should look bleaker when I get four or five hours sleep several nights in a row. But that is irrelevant. Those are the facts. And I must live within the limits of facts. I commend sufficient sleep to you, for the sake of your proper assessment of God and his promises.

Think you might need this book?

See also 10 Reasons Why We’re Sleeping So Badly.