Your attention span can be influenced by internal factors (your own brain leads you to shift from one task to another) or by external factors (something in the outside world calls to you). To boost your attention span, you must deal with both internal and external factors.

Internal factors: One of the biggest internal factors that disrupt our ability to focus is a lack of sleep. The best way to tell whether you need more sleep is to read something difficult in the early afternoon. If you start falling asleep within five minutes of trying to read, then you really need more sleep. You might be tempted to remedy this with caffeine, but while caffeine can make you feel more alert, it won’t help your brain process and store information more effectively.

A second big internal factor is frustration and boredom. The reality is most jobs have tasks that are difficult or tedious, so you need to figure out a way to stick with them despite the frustration or boredom you may feel.  If you give in to those feelings, then you learn an association between those negative feelings and stopping a task.

External factors: Of course, the modern world is also full of things that draw your attention. In open office environments, there are conversations going on around you and people passing by. If you’re the kind of person who is distracted by these kinds of noises, a white noise machine or some headphones can be a good investment.

The biggest source of external stimulation, though, comes from your email and phone. One thing that you can do to help minimize the impact of these interruptions is to park your cell phone somewhere out of reach when you are working on something important. Shut off your email program (or close that tab on the browser connected to the server). Make it hard to check the status of email and social media quickly so that you are not tempted to stop whatever you’re doing.

Ultimately, the longer you can go between interruptions, the more likely you will be to get key tasks completed. And each time you get a long stretch of work done, you are also training your brain to repeat that strategy again when working on something that requires sustained effort.