also recall that long slow running burns fat while you are running, and it is mind numbingly boring.
sprinting on the other hand burns no fat while you are running, but it is short and fun to go fast. it raises your metabolism (it and weights are the only two things that effect your resting metabolism - well, and drugs) - and it increases your pituitary glands release of gh - so you will get more fat burn and muscle building with that.
so sprint and enjoy. but don't do it everyday, do it at most 3 times a week and even then, do sprints on one day, intervals another day, and steady state the other.
you will get cut pretty quickly - I know from personal experince in school.