Factors such as age, gender and genetics affect metabolism and can be controlled. However, in the past it was thought that diet and aerobic exercise increased metabolism. Diet can have a very small effect, but strength training gets the blue ribbon for increasing metabolism - not aerobic exercise.

     Greater muscle mass means higher metabolism. For every one pound of muscle, your body burns 45 calories per day. But for every one pound of fat, your body burns fewer than two calories per day. So the more muscle you have, the higher your metabolism will be and the more calories you'll burn at rest.

     Take the following steps to add muscle and accelerate your metabolism. By doing so, you'll shift into high gear with more energy, more strength and lower percent body fat.

Consult with a certified fitness trainer or exercise physiologist to set up a safe strength-training program and help you learn the proper form. No one is too old or out of shape to benefit from added strength.

Aim for two to three days of resistance training per week for all you major muscle groups in addition to your regular aerobic exercise routine each week. (Be sure to skip a day between muscle workouts so your muscles have 48 hours to rest.)

Stick with the program for the rest of your life.