[Bama Belle]

Found this info on an ivillage site. Hope it's helpful!

The number of calories you burn while actually weight training is insignificant compared with your energy expenditure when you do continuous cardiovascular (aerobic) exercise for 30 minutes or more. There are so many pauses between sets and between different exercises that you can't keep your heart rate elevated consistently during a weight workout.

Weight training does increase your overall lean muscle mass, and that will raise your resting metabolism, which means you will burn more calories at rest. Whether you choose high reps with low resistance or more weight with fewer reps, you can achieve the same results. Your present fitness and strength levels should determine how you go about weight training.

If you're a beginner new to weight training, anything you do will make you stronger and increase the amount of muscle you have on your frame. I like people in this category to start out with lighter weights that enable them to complete 12-15 repetitions of each exercise for a couple of sets. When 2-3 sets of 15 reps is no longer challenging, we'll add weight, knowing that 12 reps will be possible with the next-higher increment of resistance. I would continue this pattern for 6-8 weeks before adding weight and dropping the number of repetitions.

When someone has completed the elementary stage of a weight program, or has been lifting weights for a while, she or he can handle higher weights with fewer reps per set. More resistance produces greater overload on the muscle fibers involved in a particular exercise. The fibers will grow faster, and you'll get stronger quicker and add more lean mass to your frame. Your resting metabolism will increase, and you'll burn more calories at rest.

Choose as many multi-joint exercises as you can, in either case, in order to engage more total muscle fibers while doing the exercise. Squats or leg presses, bench presses, lat pull-downs and overhead presses all help build muscle more quickly than isolated, one-joint exercises will. More muscle means higher metabolism means more calories burned throughout the day. It doesn't matter which route you take.