Intense exercise is far better for losing BF because of the metabolic changes that it encourages your body to make. Lift heavy weights (or use machines if you prefer) and try to make your workouts intense (really push yourself). Do this maybe 2x a week, no more is needed, and the workouts don't have to be very long either (if you're in the gym longer than 30-45 min then it's almost certainly too much). In addition, sprint once a week. I like doing 4 100m all-out sprints with about a 1 minute rest in between, it's a great workout that's over in roughly 5 minutes -- and it'll do far more for you in terms of lowering BF% than a 3 mile jog.