I've always best enjoyed working out on the treadmill. I find it not too difficult to do, except when it's a crazy hot day like it has been for the last few days, and it's easy enough that I can do something else while working out. Usually, that something else is either reading an audiobook or listening to music. My most recent treadmill book has been _The Rapture_. It isn't the kind of thing I'd usually read, but I picked it up because it was read by India Fisher, and I find her voice enjoyable to listen too. I often like to have books on the treadmill that I wouldn't otherwise read; reading something different for half an hour a day, over the course of a few months, forces me to add variety to my usual steady diet of fantasy and spacetravel novels, gulped down in a single sitting per book.