At the end of a hectic workweek, the last thing most of us want to do is to wake up bright and early on a Saturday morning. In fact, many of us elect to sleep in, either as a reward of sorts or as a way to “catch up” on lost sleep. However, doing so may result in more harm than good.
The term Social Jet Lag (SJL) describes the practice of sleeping in on weekends in order to compensate for, or catch up on, sleep you may have lost during the week, a practice that may, at first glance, seem fairly harmless.
However, at the recent SLEEP conference, an annual scientific and clinical meeting for sleep medicine physicians, and sleep and circadian researchers, it was found that “disruption to the body's circadian clock caused by late-night bedtimes followed by later weekend wake times appear(ed) to be an independent risk factor for poorer health”, to the extent that each hour of sleeping in appeared to be associated with an 11.1% increase in risk of heart disease. This is on top of earlier studies conducted on SJL that linked sleeping in to a variety of other negative consequences such as fatigue, bad moods and increased sleepiness.
While the concept of “sleep debt” is very real, the feeling of restfulness is more than just a numbers game. In other words, it’s not just about how many hours you’re getting each day or week – it’s how you’re getting them. If you’re clocking extra Zs by staying asleep during a time of day when your body’s accustomed to being awake, it has to expend extra effort to reacclimatise itself to this new arrangement. The only exception to this occurs in the face of acute fatigue (e.g. a gruelling workout, an arduous hike, etc.).
While the findings of this study may seem terrifying, there is a simple and obvious solution available to the issue of SJL: getting regular, consistent and sufficient sleep. Make use of your waking hours by planning and completing what you have to do, and spend your time before bed winding down – whether it’s with a book or with a soothing cup of (caffeine-free) tea – so that you can get to sleep on time, and avoid disrupting your circadian rhythm.