Paying off sleep "debt" takes longer than you think

I cannot overemphasize the critical importance of adequate sleep. These deep, restorative sleep cycles are a fundamental part of your body’s repair process. A number of studies have demonstrated that failing to get enough comes with consequences. Still, many Americans continue to “run on empty” during the week, with the hopes of making up for it later.

According to recently published research, however, this is a dangerously flawed approach to dealing with your sleep deficit… because as it turns out, catching up on lost sleep is not such a simple process after all.

In this small study, researchers from Brigham and Women’s Hospital followed the effects of sleep loss—both acute (defined by spending a full 24 hours or longer awake) and chronic (marked by only four to seven hours of sleep per night over a longer period of time)—on the daily functioning of nine healthy volunteers.

Subjects were monitored for three weeks on a schedule that combined 33 hours of time awake, followed by 10 hours of sleep, each “day”—translating to roughly five-and-a-half hours of sleep per 24-hour cycle.

Among the findings: Performance was always good upon waking from each 10-hour sleep session, but would deteriorate as the day went on. Furthermore, researchers noted an increasingly faster deterioration rate over the course of the study period—an outcome that can be linked back specifically to chronic sleep deficit. Finally, performance was also strongly connected to circadian rhythm—that is, the body’s natural “clock”—remaining relatively normal during the peak periods of late-afternoon/early evening, and dropping dramatically during late night/early morning hours, in conditions of both acute and chronic sleep loss.

So what does this mean for you? Ultimately, just a few days of much needed rest isn’t enough to get your body back on track after prolonged periods of sleep deprivation, and your reaction times will most certainly suffer for it. This is especially true if you are working extended hours or night shifts—and especially dangerous if you’re also driving or operating other heavy machinery.

It’s clear from this research that sleep “debt” cannot be paid off easily, and that long-term lifestyle changes are necessary for your body to function properly. I would also like to point out that simple measures of performance aren’t the only aspects of your health that are affected, especially where chronic sleep loss is concerned.

Aside from the negative impact they have on your immune response, poor sleep habits can raise your risk of coronary events dramatically over time as well, with studies linking chronic deprivation to increased total and LDL cholesterol and triglycerides, along with lower levels of health-promoting HDL cholesterol. Research also suggests that chronic sleep loss could raise your risk of metabolic syndrome by as much as 45 percent. It compromises the activity of appetite-controlling hormones like leptin, leading to a higher risk of both obesity and diabetes.

Finally, chronic disruption of your body’s restorative sleep cycles has been linked to certain cancers as well. Population studies show that breast, endometrial, prostate, and colorectal cancers are all more common among sleep-deprived individuals.

Unfortunately, difficulty sleeping can become an increasingly common problem with age, especially when combined with stress. Sleep deprivation can also be related to sleep apnea, a condition in which the sleeping individual stops breathing for frequent periods during the night, with dangerously low oxygen levels. Anyone with sleep issues should be evaluated for this condition. Additionally, women going through menopause often experience difficulties with sleep that can be related to changing hormone and neurotransmitter levels.

If you have no such medical conditions contributing to your sleep deprivation, simple changes to your lifestyle will often have a very beneficial impact: Get plenty of exercise and avoid caffeine in the evening. Try to go to bed at the same time each night, and treat your bedroom as a restful sanctuary, without unnecessary distractions like computers or televisions. As I’ve mentioned in recent newsletters, meditation before sleep can also help, allowing you to shed the stresses of daily life and calm your mind.

These are all small commitments that can be easily integrated into your evening routine for maximum benefit—not only to your daily performance, but to your lasting health, as well.

Source: Cohen, D. Science Translational Medicine, Jan. 13, 2010; vol 2: p 14ra3.