weights 20-25 rep range, 45min steady state cardio?

As the title suggests, I have a book with a weight routine and steady cardio - I am aware that this does not fit in with the current low rep/high weight thing, but how about using it for 6 weeks or so to strip off some fat, and as my body starts to adapt then change to a lower rep/higher weight and cardio based more on HIIT and walking?