Heaven forbid that you spend sometime actually focusing on a single topic and immersing yourself in it to try to see the layers authors may have put into their books.
If you're reading something that requires that little of your focus (i.e. you can read it while on an exercise bike), maybe you should choose better reading material.
Don't get me wrong, I'm all for multi-tasking where available, but why are we a culture of trying to maximally absorb information? I was hoping this article was going to tell me that I should spend less time on the dreaded reddit/hacker news cycle.