In order to focus in reading, you have to look for a quiet and cooling environment and avoid everything that involves noise and movement.
I struggle with the same problem, but what has helped me focus is listening to the music that plays while your being timed. I really like the music because it’s relaxing and doesn’t distract me. For me, listening with headphones helps fade many small distractions.
I'm using an app called binaural beats it really helps me focus in reading there are many choices in the app you can also search some topics like:sleep,study,meditate