I love running with audiobooks. People I talk to are initially thrown off (don't you need high-tempo/"pump" music?) but if you're get into the habit and don't push yourself too hard it's easy to listen to fiction 20-40 minutes at a time while doing cardio. It's positive feedback, too - I look forward to running because I get to listen to my book. And I like my book because (after getting into a routine) running makes me feel good.