That is a great question.
Intensity is what burns calories.
Remember always check with your doctor before you begin to exercise. Nat, Louisville, KY Well Nat, That really depends on your goals. I am assuming that your goal is to get in shape or sustain muscle tissue. As a rule of thumb, when you begin, you should always workout doing 2 sets of 8-15 reps per body part. This is really the ideal number of reps for females.