In short, nothing good—and just one bad night can trigger a cascade of side effects
Bad sleep 'dramatically' alters body
A run of poor sleep can have a dramatic effect on the internal workings of the human body, say UK researchers.
A Good Night’s Sleep Is Tied to Interruptions, Not Just Hours
New research shows that waking up several times in a night’s sleep can cause bad moods and limit one’s ability to focus and think.
Insufficient Sleep Associated with Risky Teen Behavior
A new study reports teens who sleep for less than 6 hours per night are at greater risk of mental health issues, substance abuse, accidents and other risk taking behaviors.
'Sleep should be prescribed': what those late nights out could be costing you
Leading neuroscientist Matthew Walker on why sleep deprivation is increasing our risk of cancer, heart attack and Alzheimer’s – and what you can do about it
What's Up With That: Why Does Sleeping In Just Make Me More Tired?
Oversleep causes a feeling similar to feeling hung over and it's caused by the same biological function that gives you jet lag.
The myth of the eight-hour sleep
Sleeping in one eight-hour chunk is a very recent phenomenon, and lying awake at night could be good for you, according to scientists and historians.
Sleep deprivation is not a badge of honor
Forgoing sleep is like borrowing from a loan shark. Sure you get those extra hours right now to cover for your overly-optimistic estimation, but at what price? The shark will be back, and if you ca…
Sleep Deficit: The Performance Killer
Reprint: R0610B Companies today glorify the executive who logs 100-hour workweeks, the road warrior who lives out of a suitcase in multiple time zones, and the negotiator who takes a red-eye to make an 8 AM meeting. But to Dr. Charles A. Czeisler, the Baldino Professor of Sleep Medicine at Harvard Medical School, this kind of corporate behavior is the antithesis of high performance. In fact, he says, it endangers employees and puts their companies at risk. In this interview, Czeisler describes four neurobiological functions that affect sleep duration and quality as well as individual performance. When these functions fall out of alignment because of sleep deprivation, people operate at a far lower level of performance than they would if they were well rested. Czeisler goes on to observe that corporations have all kinds of policies designed to protect employees—rules against smoking, sexual harassment, and so on—but they push people to the brink of self-destruction by expecting them to work too hard, too long, and with too little sleep. The negative effects on cognitive performance, Czeisler says, can be similar to those that occur after drinking too much alcohol: “We now know that 24 hours without sleep or a week of sleeping four or five hours a night induces an impairment equivalent to a blood alcohol level of .1%. We would never say, ‘This person is a great worker! He’s drunk all the time!’ yet we continue to celebrate people who sacrifice sleep for work.” Czeisler recommends that companies institute corporate sleep policies that discourage scheduled work beyond 16 consecutive hours as well as working or driving immediately after late-night or overnight flights. A sidebar to this article summarizes the latest developments in sleep research.
Opinion | Rethinking Sleep (Published 2012)
It’s not the quantity of sleep that restores and refreshes, but the quality.
Why Sleep Deprivation Eases Depression
Glial activity reveals how sleep deprivation elevates mood
Are two halves better than one whole? A comparison of the amount and quality of sleep obtained by healthy adult males living on split and consolidated sleep-wake schedules
The aim of this study was to compare the quantity/quality of sleep obtained by people living on split and consolidated sleep-wake schedules. The study had a between-groups design, with 13 participants in a consolidated condition (all males, mean age of 22.5yr) and 16 participants in a split condition (all males, mean age of 22.6yr). Both conditions employed forced desynchrony protocols with the activity:rest ratio set at 2:1, but the consolidated condition had one sleep-wake cycle every 28h (9.33+18.67), while the split condition had one sleep-wake cycle every 14h (4.67+9.33). Sleep was assessed using polysomnography. Participants in the split and consolidated conditions obtained 4.0h of sleep per 14h and 7.6h of sleep per 28h, respectively. Some differences between the groups indicated that sleep quality was lower in the split condition than the consolidated condition: the split sleeps had longer sleep onset latency (9.7 vs. 4.3min), more arousals (7.4 vs. 5.7 per hour in bed), and a greater percentage of stage 1 sleep (4.1% vs. 3.1%), than the consolidated sleeps. Other differences between the groups indicated that sleep quality was higher in the split condition than the consolidated condition: the split sleeps had a lower percentage of wake after sleep onset sleep (11.7% vs. 17.6%), and a greater percentage of slow wave sleep (30.2% vs. 23.8%), than the consolidated sleeps. These results indicate that the split schedule was not particularly harmful, and may have actually been beneficial, to sleep. Split work-rest schedules can be socially disruptive, but their use may be warranted in work settings where shiftworkers are separated from their normal family/social lives (e.g., fly-in fly-out mining) or where the need for family/social time is secondary to the task (e.g., emergency response to natural disasters).
Poor sleeping patterns link to cancer
Irregular sleeping patterns are "unequivocally" shown to lead to cancer in tests on mice, a study suggests.
Opinion | Yes, Your Sleep Schedule Is Making You Sick (Published 2017)
What jet lag, insomnia and mental illness have in common.
Extreme night owls: ‘I can’t tell anyone what time I go to bed’
What happens when your natural sleeping pattern is at odds with the rest of the world?
Scientists discover how deep sleep builds muscle, burns fat, and boosts the brain
Scientists have discovered a surprising two-way relationship between sleep and growth hormone, revealing how the brain carefully balances physical recovery with wakefulness. The findings could help explain why poor sleep harms metabolism and brain health, potentially opening the door to new treatments for sleep and neurological disorders.
