Want to be more productive? Quit multitasking.

Are you a pro at updating a spreadsheet while making an unrelated call, or knocking out email responses while in a meeting? If so, you may pride yourself on being super-efficient. But research suggests that multitasking actually makes us less productive.

In fact, people who multitask all the time may be the worst at doing two things at once. So if it isn’t really effective, why do it? Well, intuitively it can feel like we’re actually doing more in less time—no matter what the researchers say. And the idea of multitasking as the modern way to get more done is epidemic. Our jam-packed schedules contribute to the sense that we can, and should be, juggling several things at once.

Our always-connected gadgets and apps keep dinging and buzzing, announcing that something else needs our attention. But studies show that, while it may feel like we’re accomplishing a lot, multitasking is bad for productivity, stress levels, and even our brains.

Are we actually even multitasking?

True multitasking means doing two tasks simultaneously. And research shows we can only accomplish it when one of those tasks is so automatic it doesn’t require focus or thought, like walking—or when two tasks require different types of brain processing, like reading and listening to instrumental music.

That’s because each of us has only so much working memory, the part of the brain responsible for briefly storing and processing information so we can perform complex cognitive tasks—like reasoning, planning, and making decisions.

Studies suggest that our working memory can only hold a limited amount of information, which is why it’s nearly impossible to add 67 and 15 in your head while also composing an email. What we think of as multitasking is actually task switching, which is simply moving among multiple things—browsing email, responding to texts, writing a report—so quickly that it seems like we’re doing them all at once.

Our brains call it multi-taxing

Multitasking has a number of negative effects on the brain. For instance, switching from one thing to another uses up oxygenated glucose that the brain needs to focus, making us feel tired more quickly than when we sustain attention on one thing. By trying to do too many things at once, we’re actually depleting the resources we need to be productive.

Constant task-switching can also be stressful. You’ve probably experienced it yourself—a day filled with email alerts, pop-up chat windows, last-minute meetings, and “do you have a minute?” requests from co-workers can feel like you ran a marathon without actually getting anywhere. One study found that, after only 20 minutes of interrupted performance, people reported significantly higher stress, frustration, workload, effort, and pressure.

And chronic stress has been linked to memory loss, depression, and to changes in the brain regions that regulate emotion, self-control, and cognitive processing. And while multitasking can make us feel like we’re working smarter, one University of London study showed that multitasking can lower your IQ—with an effect equivalent to missing a night’s sleep.

Multitasking can make us 40% less productive

When we switch tasks to respond to interruptions, it can take a lot longer than we think to return to what we were originally doing—typically around 23 minutes. So when we’re multitasking, it takes a lot more time to get things done than if we devoted our full attention to one thing. Researchers estimate that multitasking can cost a whopping 40% of a day’s productivity. We also make more errors when we switch our attention, and the more complex the task, the more errors we make.

The prescription? Single-tasking.

Deep and singular focus is just what the doctor ordered, but in our hyper-connected world, it isn’t always easy. And in fact, the internet, emails, productivity apps, and social media might actually be training our brains to be more easily distracted, which explains why we find it nearly impossible to ignore an email once we know it’s in the inbox.

You could chuck all your gadgets and move to the woods, but luckily you don’t need to get that drastic. Experts say you can begin to retrain your brain and take advantage of deep focus by concentrating on one thing at a time, managing your use of technology, and reframing the “instant-response” expectations of your colleagues—and yourself. Here are a few tips to get started:

• Notice yourself multitasking. Multitasking may be such a habit that you’re not even aware of how fractured your attention is. Start with your morning routine—are you checking Facebook, making breakfast, and responding to emails simultaneously? How often are you burning the toast because you got lost in something else?
• Turn off notifications. Silence your cell phone and mute email, news, and other app alerts clamoring for your attention. Then determine preset times that you’ll check in throughout the day. This can feel disconcerting at first, but you might be amazed at the level of focus you can achieve with just this one step.
• Consider your environment. A quiet workspace is best for most people who are trying to focus, though extroverts are a bit better at filtering out background noise than introverts. Intermittent speech—like a nearby co-worker on a phone call—is the hardest background noise to tune out, so if you don’t have a quiet space, consider investing in some noise-canceling headphones.
• Build in time to focus. Focused work needs chunks of time, so create some spaces in your day that are free of distractions and non-interruptible. It might take some work to train co-workers to consider when you’re open to being disturbed, but it can also have a positive ripple effect that encourages them to do the same.
• Shut down online distractions. Breaks are good, and the kind of break that helps focus and productivity is a short walk that gives your brain a rest, rather than engaging in a slew of social media posts. If the temptation to check Facebook, Twitter, and Instagram is too strong, a quick search can help you find an app to block them.

Brains work best when they’re focused on one thing. While you can’t control everything that life throws at you in a day, noticing your own multitasking habits and experimenting with changes that support deep focus will go a long way to helping you feel less stressed and more productive.

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