Why are Americans so tired? Aside from hoping sleep can be replaced by a nonfat double latte, there are lots of sneaky culprits that steal our shut-eye. We covered 7 surprising reasons in Why Am I So Tired?, but they don’t stop there: here are four more things that may be sabotaging your sleep. Reason #1: Sleeping In Say what? It’s true: sleeping in can actually make you feel more tired. Why? The answer lies in your circadian rhythms. If you have a job with set hours, you probably wake up at the same time every day during the week. On the weekends, though, you may relish the chance to get a few more hours of shut-eye. However, from plants to animals to bacteria, all living things follow a built-in daily rhythm, and your body is no different. Its circadian rhythms follow a 24-hour cycle; your body temperature, metabolism, and levels of hormones like cortisol and melatonin, ebb and flow. These rhythms are controlled internally by groups of cells in your hypothalamus, but also take cues from the external environment, especially daylight. By sleeping in on Saturday morning, you inadvertently throw off your rhythms, which make you feel jet-lagged: groggy, unable to concentrate, not to mention grumpy. We won’t even get into the GI symptoms, but suffice it to say your gut hates it when you sleep in. What can you do instead? Scrape yourself out of bed at your usual time, but, later in the morning or early afternoon, treat yourself to a short nap or two, as long as they’re less than 45 minutes each. It will refresh you without making you feel hungover. Why less than 45 minutes? That’s about how long it takes to get into the deeper, more restorative phases of sleep, including REM. A shorter snooze will keep you in the early stages of sleep and won’t disrupt your circadian rhythms, unlike sleeping in. Reason #2: Interrupted Sleep Anyone who’s ever had a newborn can tell you that interrupted sleep can feel as bad as pulling an all nighter. You’d think that getting woken up for a few minutes here and there wouldn’t amount to much, but a 2014 study in the journal Sleep Medicine found that participants whose otherwise good night’s sleep was interrupted four times for 10-15 minutes at a stretch were just as cranky, unmotivated, and spacey as participants whose sleep was restricted to just four hours. Notably, small creatures not of the human variety are major culprits for interrupting your sleep multiple times a night. Cats and dogs inevitably choose 4 a.m. as the time to meow for breakfast or bark as if there’s a ninja breaking into your house. But no matter who’s waking you up repeatedly, know that when sleep gets interrupted, you lose a lot more than those few minutes you spend shooing the cat out of the room or settling the baby. Reason #3: Electronics Reading in bed has helped people wind down and fall asleep for centuries. But this century, technology is keeping us awake: the short-wave blue light emitted by our laptops, tablets, and phones suppress melatonin, the hormone that makes us sleepy. In an eye-opening (ha-ha) 2014 study in the journal PNAS, a group of participants read a book before going to bed for five consecutive evenings, while another group read on an iPad. After the five initial nights, they switched places for five more nights. What happened? Those who read on the iPad produced an average of 55% less melatonin than the book-readers, took 10 minutes longer to fall asleep, and had significantly less REM sleep throughout the night. Worse, iPad readers woke up feeling sleepier than the book readers and took hours—hours!—to attain the same level of alertness as the book readers. But melatonin suppression isn’t just limited to iPad users. In particular, many trauma survivors sleep with the TV on—they say it provides comforting background noise and makes them feel safer. But TVs emit the same blue light, so if you prefer background noise during the night, consider a white noise machine or leaving the radio on at a low volume, but ditch the TV, iPad, and other light-emitting devices. Reason #4: Not Exercising We’ve all heard that sitting is the new smoking, but it turns out that a sedentary lifestyle isn’t just bad for your health, it’s also bad for your sleep, especially as you age. A 2012 study in the Journal of Physiotherapy aggregated six different studies of adults age 40 and over with sleep problems. In each of the studies, some participants were asked to start an exercise program while others were allowed to remain on the couch. After a few months, the exercisers found they fell asleep faster, had better quality sleep, and needed less sleep medication. In sum, good sleep is both the cause and an effect of a healthy lifestyle. It can be hard to prioritize exercise and sleep in a 24/7 culture, but at least now you have backed-by-research permission to turn off your work email and take a nap! Source