The shape of your body is determined by three things: muscle, bone and fat. While there's really nothing you can do about changing your bone structure, there is a whole lot you can do about muscle and fat. This ratio of muscle to fat is commonly known as your body composition.

And what is the fastest way to change your body composition? Weight training. Why is it so effective? Because it builds muscle.

Muscle is the key to changing your body. While fat certainly gives your body shape, muscle is what gives you the shape you actually WANT!

One of the greatest things about muscle is that it burns calories all day long, even when you're lying on the couch. What this means is that the more muscle you have, the more calories you'll burn during the day and the more you'll be able to eat without gaining weight. Sound interesting? There's more.

Weight training stimulates your metabolism more than aerobic training such as cycling or walking. This means that you'll continue to burn calories long AFTER you've completed your weight training session. The calorie-burning effect of aerobic training generally declines rapidly once you stop the exercise.

Beginning trainers, who are just starting with exercise, are often under the impression that they should stay away from weight training because they might gain weight before they start losing it.

I like to use a car as an analogy. Imagine your body is a car, your muscles are the cylinders in the engine, and your bodyfat is the gas.

With a four-cylinder car, you only burn a minimum amount of gas/fat. Weight training and building more muscle is the equivalent of putting more cylinders into your engine. As you can imagine, you'll burn a whole lot more gas even while idling! And, just like a car with more cylinders, you'll be a lot more powerful too!

The bottom line to you is this...with more muscle, you'll get greater fat loss with less effort.

While it certainly is a possibility that you could gain weight before losing it, if you gauge your success solely by numbers on a scale then you're not getting an accurate picture of yourself. Measure your progress by how you feel, how you look and how well your clothes are fitting, not by which direction the needle on a measuring device is moving.

At the end of the day, I'm not suggesting for a moment that you should eliminate cardiovascular training from your exercise routine, but, if you are struggling to lose fat and keep it off, weight training may be just the thing you need to lose that fat and keep it off for good!