Many researchers have tried to understand how insufficient sleep accumulates over time. Sleeping more on weekends or taking a nap, is it really a good idea?
Does sleeping five hours a night from Monday to Friday, then having two lazy mornings on the weekend allow us to meet our sleep needs?
Is Weekend Sleep Really Effective Against Sleep Debt?
For several years, scientists have published studies on this subject. While the majority reiterated that it was impossible to make up for lost sleep, work published in 2018 claimed that getting more sleep on weekends could negate some of the health risks associated with lack of sleep for the week.
But a study, published in March 2019 by Current Biology (source 1) and cited by theTime, echoes previous beliefs. The researchers explain that the extra weekend rest is not not enough to compensate for the loss of sleep. They add that the benefits of weekend recovery are transient. Indeed, it is impossible to think of sleep as if it were a bank account: we subtract two hours on Thursday evening, and add them on Sunday morning. It’s a little more complicated than that.
Prefer a nap to a long night
Based on research reported by the Time, a person would need four adequate days of rest to compensate for an hour of lack of sleep. It is therefore mathematically impossible offill a week of bad sleep in just one weekend. Result: lack of sleep accumulates over time. The consequences are often tired, a loss of vigilance and efficiency, a disruption of the circadian clock, a lag that is difficult to catch up, an increase in calorie consumption, and health risks.
If you are exhausted by Saturday, opt for an afternoon nap rather than a long night, experts advise. Start by exposing yourself as much as possible to light in the morning, in order to maintain a regular biological rhythm. Then schedule a nap of at least 20 minutes in the afternoon, not too close to bedtime. But the ultimate goal remains, of course, to sleep regularly and sufficiently throughout the week, so as not to have any delays to catch up.
How sleep affects work efficiency
In Finland, a study looked at the impact of sleep on work efficiency. And it would seem that bedtime impacts professional performance. Indeed, those who go to bed late are twice as likely to underperform at work than the mornings.
These findings, published online in February 2021 in the journal Occupational & Environmental Medicine (source 2), ensure that night owls are at increased risk of early retirement due to a disability. Morning chronotypes tend to do best in the early morning, while evening chronotypes do best in the evening. The chronotype is largely genetic, but environmental factors, such as exposure to daylight, work schedules and family life can also influence it.
Due to an hour of late sleep, night owls don’t sleep seven hours a night and are therefore in sleep debt. In the long run, the researchers say, this sleep deprivation is linked to overall health and poorer cognitive performance, which could hinder productivity at work.
For this study, the researchers relied on data from the 1966 study of the Northern Finland Birth Cohort. This is an ongoing study among the general population, originally composed of 12,058 children (6,169 boys and 5,889 girls). At the age of 46, the participants were asked about their professional life, their health and their sleeping habits to find out their natural chronotype.
Compared to larks, owls scored poorly on all variables related to sleep and health. They reported more often short duration of sleep, insomnia and high levels of social jet lag. And they were more often single and unemployed. About 1 in 4 of men (28%) and women (24%) classified as owls performed worse at work by the age of 46. The odds of underperformance were twice as high in owls as in others.
Sleep deprivation: caffeine won’t help you that much
We shouldn’t rely too much on caffeine to “save the furniture” after having slept little or badly, according to a study published on May 20, 2021 in the Journal of Experimental Psychology: Learning, Memory, & Cognition. Researchers have evaluated the effectiveness of caffeine consumption in countering the negative effects of sleep deprivation on cognitive abilities. Over 275 participants were invited to perform a simple attention task as well as a more demanding “space management” task, which required performing tasks in a specific order without skipping or repeating steps.
Verdict: “We have found that sleep deprivation impairs performance on both types of tasks, and that consuming caffeine helps people complete the easier task. However, this had little effect on the performance of the space management task for most participants.”, Summarized Prof. Kimberly Fenn, who led the study, in a communicated. And the researcher adds that if “caffeine can improve the ability to stay awake and deal with a task”,“it doesn’t do much to prevent the kind of procedural errors that can cause medical errors [ou encore] car accidents”. It would therefore be better to give priority to sleep.