While Running is a great activity to aid in fat loss, it has one drawback, it only speeds your up your metabolism while running and for a short period afterwards. Shapefit.com adds that if you would like your metabolism to fly at the speed of light 24 hours a day, get to sprinting. Sprinting not only burns HUGE amounts of calories while sprinting, it also keeps your metabolism flying for days after. Read more on sprinting at the above link.  KEEP MOVING!-Elizabeth, CPT.