If you’re not tired, you’re not busy enough—you could be doing more.

Sound familiar? If so, you’re not alone. The sentiment that tired equals productive is a ubiquitous one. This belief implies that successful people are tired because they are busy, that they put in the long hours needed to get to the top, and that doing so shows dedication. And sure, it does show dedication. Unfortunately, the long hours might be canceling themselves out by ruining your ability to be as productive and alert as possible.

The “I don’t sleep” culture is especially pronounced on college campuses and throughout Silicon Valley.

College students will sleep when they’re dead

Yale Daily News ran a feature last year highlighting the pervasive culture of sleep deprivation on college campuses. The opening anecdote frames the problem perfectly: after a few weeks of sleeping for only four hours a night, a student falls asleep during a lecture, right in front of her professor.

Students describe the attitude toward sleep during college as “I’ll sleep when I’m dead.” Students have this idea that sleep deprivation is something to be proud of. They wear dark under-eye circles and exhaustion like an Olympic medal: it shows they have drive and are important and successful. Among these students, sleep is seen as slothful or weak Those who are well rested often appear lazy or unable to reach their potential.

Silicon Valley never sleeps

The same attitude runs rampant in the tech sector. There is always more work to do, and working excessively to get things done is prioritized over getting adequate rest and doing better-quality work. Yahoo! CEO, Marissa Mayer, in an interview with Bloomberg Businessweek, claimed that one of the keys to her success during her stint at Google was hard work. And in this case, hard work meant putting in 130 hours a week. She accomplished this by planning every moment of sleep, when she would shower, and even every trip to the bathroom.

For those keeping score, 130 hours a week equates to almost nineteen hours a day, seven days a week. If you’d like a day off, you’d have to put in almost twenty-two hours each day. And often, that’s exactly what happened. Mayer claims she worked at least one all-nighter a week for her first five years at the company. She also claims that she can tell which startups will succeed and which will fail based on their willingness to put in those kinds of hours.

This attitude sounds illogical to most people, but in the Valley, it isn’t so far-fetched. In fact, Facebook co-founder Dustin Moskovitz called out the tech industry as a whole for encouraging unsustainable work environments where this sort of intense dedication—and the associated lack of sleep—are encouraged and even rewarded.

The health impact of inadequate sleep

How’s this for irony? People often forgo sleep to get more done, but that very lack of sleep makes it harder to, well, get things done. Fatigue, difficulty concentrating, poor attention span, and mental sluggishness eventually give way to feeling burnt out as you try to sleep even less to make up for your worsening performance.

It doesn’t take long for the effects of sleep deprivation to catch up to you. In the short term, you might experience episodes like the college student above, whose body simply couldn’t handle it and gave out. You may even suffer from temporary cognitive impairment and emotional side effects. And in the long term, you could face serious health consequences for not sleeping enough.

And then there’s the caffeine. Obviously, less sleep means less energy. Many folks try to counteract this lack of energy with coffee and energy drinks—but these beverages are a quick, temporary fix. The inevitable caffeine crash just leads to more tiredness, which in turn leads to more caffeine intake. Many people may even suffer from other issues such as increased anxiety, faster heartbeats, shakiness, nausea, irritability, and weight gain as a result of this extra caffeine in their system.

Studies have reported that going seventeen to nineteen hours without sleep produced cognitive effects equivalent to a blood alcohol content (BAC) of .05%. After twenty-one hours awake, that impairment is the equivalent of a BAC of .08%—the legal limit for driving in most states. Research strongly argues that under these strenuous circumstances, people are incredibly unlikely to perform their best work.

Getting too little sleep over the long term is associated with numerous health problems. Obesity, high blood pressure, breast and prostate cancer, and mood disorders such as depression are just a handful of the serious health issues that have been linked to sleep loss.

What’s being done about it?

On college campuses, sleep education programs inform students of the dangers of not getting enough sleep. Many institutions also provide napping zones and encourage students to take advantage of them to alleviate the lack of sleep that unfortunately can come with the college experience. This can be an effective strategy—although some could argue that it encourages poor sleeping habits rather than actually solving the problem.

Companies are also getting on board with quality-sleep initiatives. Many companies in Silicon Valley, including Google, now provide nap rooms for their employees to use when they’re feeling too worn down. And MattressFirm, one of the largest bedding retailers in the country, runs a campaign to encourage people to pay attention to the way they sleep. This initiative focuses on the technology included in modern mattresses, and the company hopes this emphasis will build awareness and encourage consumers to take their rest more seriously.

What about your own sleep habits? Are you getting enough? Keep this information in mind as you think about how much sleep you get—and why. Is being a part of the “I don’t sleep” culture worth the cost of being consistently exhausted, unproductive, and ill?