We're been trained that focus is the key to productivity. The only hitch is that it doesn’t always work, according to expert Elizabeth Grace Saunders in an article for Fast Company. In fact, some situations just aren’t meant for long stretches of intense, unbroken focus. 

Here are three common situations when intentionally switching tasks is the most efficient thing you can do to stay productive.

1. Knocking out small, boring tasks.

Most of us tend to procrastinate and leave certain mundane tasks on our to-do lists for way too long. One way to help overcome "small-task fatigue" is to deliberately switch gears between different types of activities, even if they’re all minor. Letting your mind wander within a certain type of task can reduce your resistance to them.

Another effective way to task-switch is to switch between boring and (relatively) exciting tasks. 

2. Rotating deep-focus tasks.

For many, getting in even an hour or two of concentrated work time is an accomplishment. But if you’re among the lucky few who can clear even longer stretches to focus on tasks requiring thoughtful attention, you should still plan on setting a timer.

Author and research Cal Newport says four hours is the cognitive limit and recommends even breaking that up into two-hour sessions in a typical work day

By switching gears periodically, you can stay focused without getting mentally fatigued,

3. Problem-solving.

Sometimes the best way to solve a problem is to stop trying to solve it. Switching tasks can break your brain out of a focused mode that isn’t getting you anywhere and lead you into a more diffuse mental state where useful ideas may surface.

Just remember: You aren’t procrastinating. You’re just giving your brain the variety it needs to stay alert — and productive — for longer.