In my last column of the semester, I would like to present a large and important mission for you to undertake this summer. Should you choose to accept, nearly all aspects of your life, from your cognitive performance to relationships to your physical health, will benefit immensely.
I’ve written previously to debunk myths about my favorite topic — sleep — but, in this column, I emphasize something different. Affecting all of the other habits that comprise overall well-being, adequate sleep is perhaps the most important element of a healthy lifestyle.
However, many of us are sleep-deprived without even knowing it. Each person has their own ideal amount of sleep they ought to be getting each night, and our bodies have at least a two-week sleep memory. That means if your ideal amount of sleep is 8.5 hours per night, even if you sleep 8 hours per night — within the the Center for Disease Control and Prevention’s recommendation — your physical and cognitive performance will still suffer.
If your ideal amount of sleep is 8.5 hours per night and you got 8 hours of sleep last night, even if you get 8.5 hours of sleep every night from here on out, you will still be performing worse for the next two weeks. Thus, it is crucial to identify your own ideal number of hours to sleep and to get that amount of sleep every night. In circumstances when you don’t have time to get your ideal amount of sleep for a night, it is important to make up the deficit as soon as possible in order to avoid the negative effects of sleep debt.
To find out your ideal number of hours of sleep, figure out how long you naturally tend to sleep after you have repaid all your sleep debt. Keep in mind that though you might naturally sleep for 12 hours on a weekend, for instance, that is likely an overestimation of your ideal amount of sleep because you are making up for lost sleep during the week.
Find a time when you are able to sleep as much as you want for several days or weeks. This will allow you to make up for accumulated sleep debt. Then, when you find yourself sleeping a consistent amount each night and waking up without an alarm clock, fully refreshed, you know you are hitting your ideal amount of sleep per night. According to the Sleep for Science lab where I worked last summer, the average ideal is 8.4 hours of sleep per night.
Sleeping any less than your ideal number of hours will make you partially sleep deprived. Repeated over many nights, partial sleep deprivation can make you accumulate a sleep debt that has a negative impact on everything you do.
A meta-analysis of studies has demonstrated that sleep deprivation strongly impairs human functioning. Further, partial sleep deprivation has an even stronger effect than either short-term or long-term acute sleep deprivation — i.e. pulling an all-nighter.
Sleep quality and quantity are closely related to student learning capacity and academic performance. Studies have shown sleep loss causes poor declarative memory and procedural learning. One study even found long sleepers — people who sleep more than nine hours a night — reported significantly higher GPAs than short sleepers— people who sleep less than six hours a night. Another study found while subjective sleepiness ratings eventually level off with accumulated sleep debt, cognitive performance continues to decline. Thus, sleep-deprived participants in the study were performing worse and worse on cognitive tasks, but they were largely unaware of their decline since they didn’t feel much sleepier.
The book “SLEEP: A Very Short Introduction” also points out that sleep debt is ”associated with weight gain, increased fat mass deposition, obesity, and diabetes.”
Following sleep restriction, the body produces more of the hormone ghrelin and less leptin, which causes subjects to eat more, especially carbs. The effect of excess carbs is further exacerbated because when we are sleep deprived, our insulin is less effective at lowering blood glucose. Thus, sleep restriction often leads to eating carbohydrates late at night. However, because of these hormonal effects, a meal eaten at 1:30 a.m. will result in higher blood glucose, insulin, and fats for several hours after as compared to eating the same meal at 1:30 p.m. The effect size of the study is so large that the night meals makes blood glucose levels look like those of a diabetic.
Even worse than the cognitive or physical effects, a meta-analysis of studies found that our moods suffer most of all the negative effects of sleep deprivation, and again that partial sleep deprivation accumulated over several nights causes worse moods than total sleep deprivation.
So, your mission for the summer is to figure out your ideal amount of sleep and start getting that amount of sleep every single night. However, sleep deprivation is dose-dependent, and finals are fast approaching. Therefore, the more you can sleep between now and then, the better your performance will be. Give yourself time to sleep your ideal amount, every night, and re-pay your sleep debts ASAP. If anyone gives you beef about sleeping the day away, you now have an arsenal of defenses.
Karen Konkoly, ’17, is a columnist for The Brown and White. She can be reached at [email protected]