I´m lazy when it comes to running, i hate that **** but prefer sprints, or just some nice 5km ( little bit more than 3 miles) run
Both. You will haver a "fire fight" at some point (think Ward/Gatti R9) and that conditioning from sprinting will benefit you when you go all out. That said, what will keep you going is the cardio from the long distance running. Both have a place.