As far as calories go.. one mile burns roughly 100 calories whether you walk, jog or run it. The thing is, if you do sprint intervals over that mile, you will raise your metabolism for HOURS AFTER the cardio as well! So you will be burning more calories overall if you do HIIT as opposed to steady-state (HIIT is very effective for fat burning). While I recognize there are more components that go into it than this, that is the BASIC explanation =)