Having new muscle mass will in fact increase your metabolism. As you add muscle your body will begin to burn more calories and in longer durations throughout the day. At some point and with enough constant exercise you will be an efficient fat burning machine. But you really have to add muscle to get to this point.
The body works as a single unit, just with different parts. What you do with your legs will affect what happens to your upper body. In fact, one the best ways to get bigger biceps (for example) is to do squats. This seems counter-intuitive, but it’s the truth. Because your legs are the biggest muscle of your body, when you strengthen them it helps you build muscle everywhere else too, including your abs.
This doesn’t mean that the Ab rocket doesn’t deliver or that it’s worse than other ab machines. No ab machine alone can help you get flat abs. It is always just one part of a more complete diet and fitness solution.
When beginning a muscle gaining program, you will want to increase your caloric intake. However, the question is, how much more should you eat? If you are working for a substantial gain in muscle, you may want to add an extra 750 – 1000 calories to your daily diet. Over the course of a week, this amount of calories will really build up.
For beginners, a complete workout routine review is the best way to pack on muscle very quickly. Stimulating all the muscles in the body at once tends to trigger growth provided your nutrition is in order. Just make sure that the workout routine is a tried and tested one that is both balanced and not overly taxing.
If you gain weight easily and put on muscle without much lifting, finding a routine should not be too difficult. You can look in a muscle magazine. These are intended for a wide audience and help people that gain weight easiest. Another good source of advice might be someone at they gym who also gains weight and builds muscle easily.
So the cons of the whole body routine are that the workouts are lengthy, tiring and physically demanding. Also, if you have any weaknesses, it is difficult to focus on individual muscle groups and full body workouts are often dominated by compound exercises. While they are more favourable for overall development, some weak parts could potentially be neglected.