Developing tone in your body or bodybuilding is simply the process of increasing the muscle mass of the body and decreasing the amount of fatty tissue in the body, lowering your body fat percentage. This is accomplished through the use of progressive resistance training. Progressive resistance simply means to progressively use heavier weights as your muscles get stronger.

Increasing resistance is possible due to the body's ability to adapt to stress by becoming stronger in response to the stimulus of exercise. Simply put, when you work a muscle hard, the fibers are actually damaged or broken down and the body responds by repairing the muscle and making it slightly bigger and stronger to prepare for the work to be repeated. If the work (exercise) is repeated frequently (with enough rest in between sets and workouts for the muscles to recover and repair respectively) with increased resistance each time, theoretically, the muscle will get progressively larger and stronger. That is the basis of bodybuilding weight training.

It is a simple process, but there are many variables that can affect how fast and how much the muscle will grow. These factors include, but are not limited to, the following:

1) Nutrition
2) Rest
3) Intensity of workouts
4) Frequency of workouts