Ever notice that every afternoon, you get a case of the sleepies? It’s that time of day when you find yourself nodding off or longing for a cat nap. We often blame the high-carb lunch or boring meeting for this phenomenon, but turns out, there’s more to it than that.
Two times a day our bodies go through what’s called a circadian low. Simply put, this is a time when your body wants to be asleep. We hit these periods usually between the hours of 3 a.m. and 5 a.m. and then again 12 hours later, between 3 p.m. and 5 p.m. The body longs to be in deep sleep during this time and if it has to be awake, like during a staff meeting, it will struggle to stay awake.
If you didn’t get a great night’s sleep last night, or haven’t slept well for a few nights in a row, your circadian lows will be even more intense. Say you only got four and a half hours sleep last night; when 3 p.m. rolls around today, you will struggle to stay awake. If you suffer with sleep apnea or had two terrible nights of sleep, your afternoon low might actually cause you to fall asleep at your desk. And if you are sleep deprived today, tonight when you hit the bed, you will fall dead asleep and most likely will not wake up between the hours of 3 a.m. and 5 a.m.
From a physiology standpoint, how we Americans work makes no sense. Our go-go-go lives are no longer in sync with our sleep cycles and our bodies are taking the brunt of it. We are working earlier shifts and staying at the office later and later into the night. There is even a growing body of research looking at the weight and health of children, and science is suggesting that the best time to go to school is actually around 8:30 a.m.
Poor sleep is also a precursor for weight gain. People who are chronically sleep-deprived tend to gain weight and are also at higher risk for diabetes. After a few days of poor sleep, the body struggles to maintain a normal blood sugar level, and we actually function at a pre-diabetic level. So be aware, those bad-night sleeps are doing more harm to your body than you realize.
As for our safety, the most unsafe time to drive is actually between midnight and 4 a.m. Our bodies want to be asleep during the dead of night, but when we push ourselves to keep performing, we set ourselves up for poor judgment, slower reaction time and skewed concentration. It’s a dangerous combination for driving, yet so many of us do it.
From a performance standpoint, try to avoid holding key meetings or making crucial decisions during that circadian low time frame. Also be aware that at the end of your work day, you will be less alert and have a higher chance of having an accident when heading home in the late afternoon. And again, if you slept poorly the night before, your sleepiness will feel even more intense.
If you have no choice but to work through a circadian low, increase your activity level or have a small dose of caffeine to get you through. Switch from sitting to standing, or go for a walk; anything that will help combat that dip.
Just remember, it’s normal to get the afternoon sleepies, but please, for everyone’s sake, don’t schedule an important meeting then. No one will remember what you said!