i used to sprint in high school
100 meter dashes, the training for it was brutal!
many many 100 meter sprints everyday
i used to listen to the song "more human than human remix by rob zombie"
when i sprinted, started my sprint when it started to go "MORE HUMAN THAN HUMAN MORE HUMAN THAN HUMAN"
i haven't sprinted in a year, i hate listening to that song now, even listening to it is painful like the training for the 100 meter dash
i don't do cardio at all now, i hate it
i haven't done any form of cardio in 6 months
good luck Gene