Your Alarm Clock Is Bad for Your Health. (Here’s How to Wake Up Without One.)

Read more from our #SLEEP primer here.

Whoever invented the alarm clock must have possessed a deeply cruel streak. After all, an alarm clock’s sole purpose is to jolt or jar or propel you out of a peaceful slumber, to raise you from your warm, comfy bed in such a way as to discourage continued rest. It’s also an aptly named appliance: As all alarms are meant to alert you to the threat of danger, you should be forewarned that awakening to a loud blaring noise day after day can be dangerous to your health.

Even if you set your clock to play music or ascending chimes of a bell, if it strikes at the wrong time during your sleep cycle—when you are in deep sleep, for instance—it could cast a shadow over your entire day. Here’s why. When your alarm sounds, pulling you from a deep sleep, it triggers a sequence of unnatural and unhealthy involuntary physical responses. One of them is sending adrenaline coursing through your body—triggering the same fight-or-flight response as if you were facing down a hungry lion or other imminent bodily harm. This causes your heart rate to increase and your blood pressure to spike. A study by the National Institute of Industrial Health in Japan confirmed that participants who were suddenly awakened had higher blood pressure and increased heart rates than those who were allowed to wake up in their own time.

Maybe you hit the snooze button and pull the covers over your head. This is not a great idea. You might think that 10 more minutes of sleep will finish out your natural sleep cycle so you’ll wake up feeling refreshed, but that’s not what happens. As you drift off, your brain hits the reset button and your sleep cycle starts all over again. When your alarm goes off for the second time, you’re likely to be in an even deeper, earlier phase of your sleep cycle, so you’ll get up feeling worse than you would have if you’d gotten out of bed the first time. Way to grumpy-start the day.

If all these biological misfires weren’t enough, a study published in the Journal of the American Medical Association found that morning grogginess from being jolted awake, called sleep inertia, can dampen your mental acuity—a good reason to delay important decision-making until the fog clears. And the more abruptly you’re awakened, the more seriously fuzzy-headed you’ll be. Though it may feel like you’re roused into instant consciousness when your alarm goes off, in reality the physiological process is far more gradual. Brain-stem arousal systems (the parts of the brain responsible for basic physiological functioning) are activated almost instantly, but the prefrontal cortex (the part of the brain involved in decision-making and self-control), can take longer to come on board. Said Kenneth Wright, a neuroscientist and chronobiology expert, “Cognition is … worst near habitual wake time.” One study found that sleep inertia can take anywhere from two to four hours to dissipate completely.

So what’s a working stiff or a responsible parent supposed to do when you’ve got either an 8:00 a.m. scrum or a starving kid? When sleeping away the morning is not an option?

How to Wake Up Without an Alarm

What if you could train yourself to to wake up rested and refreshed a few minutes before your alarm goes off? Well, you can.

The key is understanding how to use your body’s natural circadian rhythm—i.e., your 24-hour body clock—to your benefit. Your circadian rhythm is what makes you feel alert or sleepy, depending on the time of day. When your daily schedule is in sync with your body clock, you’ll wake up naturally alert without an alarm because your body was ready to stop sleeping. (Conversely, when an alarm forces you awake before your body is ready, you’ll drag yourself out of bed feeling like crap.)

To banish an alarm clock from your life, you’ll need to create a consistent rhythm from day to day. If you go to sleep around the same time every night knowing when you need to wake up in the morning, you can actually train your body to come to at the right time. However, the plan won’t work if you’re completely exhausted. Meaning you can’t tame your circadian rhythm if your body is consistently sleep deprived.

Step one is to figure out how much sleep you really need to function at your best. While most people do well with seven to nine hours, you’ll want to know if you’re at the high or low end of that range. To do this, set aside a few days (maybe over a long weekend or while you’re on vacation) and let yourself to sleep in until you’re good and ready to get up. Once you’ve determined that, count backwards from the time you have to wake up to nail the hour that (in a perfect world) you should be going to sleep. For instance, if you require a hard eight and want to be drinking your first cup of coffee at 6:30 a.m. sharp, you should be hitting the hay no later than 10:30 p.m.

If that’s earlier than you’re used to, start backing up your bedtime gradually, in 15-minute increments—11:15 p.m. during the first week, 11:00 p.m. during the second week, and so on, until you hit your goal. Transitioning slowly gives your body a chance to adjust to a new schedule, making it easier to actually fall asleep.

Step two is establishing a bedtime routine, and some good sleep hygiene habits. An hour or so before your new bedtime, dim the lights, turn off electronics, and relax—take a warm bath, read a few pages in your book, or meditate. Come morning, it’s a good idea to get some sun (or bright) light exposure as soon as possible, as that signals your body and brain that it’s time to wake up. This might mean leaving the blinds or curtains open just enough to let in the light, or putting your lamps on a timer if you are rising before dawn.

Sleep specialists recommend trying not to sleep in on weekends as that can wreak havoc on the routine you’ve worked hard to put in place. Better to take a 20-minute power nap (between the hours of 2:00 and 4:00 p.m. when your natural circadian rhythm dips) if you feel overtired than to throw off your body clock.

Alarm Clock Alternatives

If all else fails–i.e., early bedtimes are giving you a hard time–think about waking up to a kinder, gentler alarm, such as these sunrise wake-up alarms, or downloading an app for your phone that promises to ease (rather than jolt) you into the start of a new day. Not only are they healthier options for your body, they’ll ease the wake-up process, and leave you a little less cranky about opening your eyes.