Study: Weekend Snoozes Don’t Fully Make Up for Weekday Sleep Loss

Sleeping in a few extra hours on the weekends might not be enough to combat the self-incurred damage from weekday sleep deprivation. According to a study from the University of Colorado Boulder, sleep restriction for just a 5-days dysregulated the internal circadian clock and increased late-night caloric intake, leading to weight gain. A recovery period over the weekend to sleep in was unable to mitigate these symptoms compared to a control group sleep deprived over the weekend as well. Weekend recovery sleep is therefore insufficient to counter against the metabolic consequences of prolonged sleep deprivation.

Weekend recovery sleep doesn’t prevent weight gain or reduce insulin sensitivity. Image credit: Wok Apix.

In our productivity-oriented modern society, sleep is typically one of the first casualties in our constant battle to do it all.

We often sleep in on the weekend to counter the sleep deprivation we self-incur during the working week, to varying success.

Sleeping less than 7 hours per night has been linked to a host of poor medical outcomes both mentally and physically. Psychological symptoms include fatigue and inattention, while physical ones include weight gain and increased diabetes risk.

Although we may feel reinvigorated after an 11-hour hibernation following a week of exhaustion, new research out of the University of Colorado suggests that the adverse effects of sleep deprivation linger on.

To specifically investigate the influence of weekend recovery sleep, the authors studied three groups of subjects over a week and a half period, with workweeks flanking an experimental weekend. One group was as a control group allotted the sufficient 9-hour daily sleep, one was a sleep deprived group getting only 5 hours each night, and the final one was a weekend recovery group, that was deprived during the weekday, and then allowed unlimited sleep over the weekend.

By looking at energy intake and metabolic measures, the authors were able to infer physiological activity between the conditions. It has been shown that sleep deprivation entails body-wide metabolic changes, but restorative effects of weekend rest was unknown.

First, the authors found that unrestricted sleeping-in on the weekend did not make up for the total number of sleep hours lost during the workweek deprivation.

The extra hours gained on Friday and Saturday nights were all but washed out by Sunday night, when they had to awaken early once again (even though they chose their own bedtimes). This data suggests that the ability to sleep in on the weekends following a workweek of restricted sleep hours does not necessarily result in individuals making up the missed sleep on an hourly basis.

An important finding of this study was that sleep restriction had substantial effects on the circadian clock timing. Our circadian clock is the driver of cyclical physiological processes that affects numerous cellular functions and gene programs regulating metabolism and sleepiness, to name a few. The regularity of our clock is important for our bodies to use resources at proper times of the day, predicting our needs so we can function optimally.

Melatonin is one element of the circadian clock, whose levels rise and fall every day, and is often used as an indirect measure of our clock timing. Melatonin measurement showed that sleep deprivation delayed both the start and end time of ‘biological nighttime’, and that this delay was not rescued with weekend recovery sleep. As the regulatory mechanisms desynchronized, energy consumption also drastically shifted.

Across all groups, the largest share of total caloric intake came from post-dinner time, but this fraction grew in the sleep restriction group during the weekdays, and then dropped off over the weekend in the weekend recovery group, but not in the sleep deprived group.

These findings were further explored physiologically by looking at insulin sensitivity in the body.

Hepatic insulin sensitivity was lowest in the weekend recovery group, possibly due to the wide fluctuations in energy intake over the trial period, and correspondingly produced the slowest glucose clearance from the body.

Together, the study provides evidence that sleeping in on the weekend may produce short-term emotional benefit, but does not fix the physiological ailments, as, “metabolic correction does not occur quickly,” according to co-author Robert H. Eckel, MD.

These findings also indicate that the disruption of sleep time may have its own negative consequences, such as the dysregulation of the circadian clock, that can remain even after returning to a regular sleep schedule. So perhaps next time you’re ready to binge one more episode late on a worknight, consider saving it for the weekend, and your body will thank you for it.

The results were published March 18, 2019 in the journal Current Biology.

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Christopher M. Depner et al. 2019. Ad libitum Weekend Recovery Sleep Fails to Prevent Metabolic Dysregulation during a Repeating Pattern of Insufficient Sleep and Weekend Recovery Sleep. Current Biology 29 (6): 957-967; doi: 10.1016/j.cub.2019.01.069