Ask ten people what type of exercise you should do to burn fat and fire up your metabolism and probably all say the same. They will tell you to do 30-40 minutes of moderate aerobic exercise on a treadmill, elliptical, stepper, etc. for 3-5 times a week.
They will probably tell you that more is better ... 4 times a week would be better than 3, and 5 times a week would be even better.