When I was in college I would study by making flashcards, don't judge. I'd take my trusty flashcards to the gym with me, run on the treadmill and go through each one, committing it to memory. I wouldn't let myself off the treadmill until I could effortlessly go through each and every flashcard and come up with the right answer (I also did this in the sauna, and wouldn't let myself out of the sauna until I had memorized every singly painting for my Art History courses, sick?). It probably wasn't smart, and it definitely was a bit masochistic, but it was effective.
Now studies have finally confirmed that this maniacal method may have actually been smart. A recent New York Times article talks about a series of studies that prove exercise can increase our ability to remember.
So while I do not recommend reading while riding, maybe swapping out music for an educational podcast every now and then could be a good thing.
Oh, and not to brag, but I got more 100%'s on tests studying while on the run than any other way.
Read the article over on the New York Times site, here.