Muscle Development
For the most part identifying the fastest ways to build muscle must not always involve weight training or calisthenics exercises. Although pumping iron or using the natural weight of your body is imperative for building muscle mass, it is only 40-50% of the picture. Generating muscle mass is a endeavor that requires making micro-tears to your muscle cells, which results in them building themselves back up stronger. Given this, anyone who wants to increase definition rapidly will not reach their desired result if they over do it and stress their muscles beyond repair when doing calisthenics (whether that involves free weights or your own body's weight does not matter).
While doing calisthenics is important, giving your body satisfactory rest and eating properly are just as important. The majority of people only do what they understand has a large impact on building muscle (resistance training), while neglecting the less understood side: rest. When you slumber your body human growth hormone, which is vitally important when enhance definition.