Ok Teppy, first of all you need make a clear distinction. Is your goal to lower your body fat or lose weight? There is a difference between the two.
If you want to lose weight, burn more calories than you take in.
If you want to lower your body fat here are a few things:
1. Percent-wise, your body burns more fat during aerobic training (long distance running) compared to anaerobic training (sprints). BUT since the intensity of aerobic training is always less compared that of anaerobic training (sprints, weightlifting), it is not as efficient for burning fat.
2. As you get fitter aerobically, your muscles adapt and require less energy to do the same amount of work. This makes burning stored energy slower - you'll have to run longer distances to burn the same amount of fat.
3. With anaerobic training (high intensity) you burn more energy for the same period of time but you will also probably build up muscle which is heavier than fat.
From my experience and from all the literature I've read, Fartlek exercises
and interval drills
seem to be the most efficient ways to burn stored fat.