Typically speaking, multitasking makes you worse at everything. There’s plenty of scientific research to back this up and you probably have your own anecdotal evidence to support it. But sometimes, you just might need to—and sometimes, it just might be OK. The times when multitasking actually works are pretty rare and specific, so here’s what you need to know. 

Why not multitask all the time?

When you multitask, you’re interrupting yourself and your progress on every single task you’re doing. It’s considered by researchers to be “interruption behavior that decreases efficiency and wastes time.” Your performance slows down, your errors increase, and you get less done (or at least less done well) than you would if you scheduled your day so you approached one to-do list item at a time.

Obviously, it’s best to avoid this altogether. Get yourself a planner and allocate your time wisely so you have sufficient space to do one task at a time. 

When might multitasking work

That said, lives are busy. Some things just don’t go according to plan and there’s nothing you can do about it. You may find that you need to double up on activities just to get it all done. If possible, only multitask in one of these two situations: 

When you’re not working on something too complex and can handle a brief, even simpler interruption (like responding to an email that pops up while you’re organizing your desktop)

When one of the tasks is something you practically do on autopilot, like walking on a treadmill or brushing your teeth

If you’re listening to an audiobook while you run or calling your mom while you drive, that’s fine, as long as you’ve run or driven so much that it’s pretty much second nature. Still, anything that makes it complex—like unexpected road construction or a stretch of street lights going out—can suddenly turn the task into an unfamiliar one, and that’s when multitasking won’t work as well. 

To the best of your ability, avoid doing it altogether. Try using the Pomodoro technique to work on one task for a sustained amount of time, then take a five-minute break before getting back to it. During that break, you can shift gears, respond to emails, call people back, relax, or do whatever else. Pick up a timer to keep track of how long you’re working so you don’t accidentally get sucked into multitasking by checking your phone for the time and noticing a message that needs responding to.