In order for muscles to increase, 3 things are needed:
Exercise is required to make the muscular tissues work. When you use power it causes microscopic damages to the fibers. The process of Hypertrophy and influencing your fast twitch type II muscle fibers increase your muscle size.
You body needs food to rebuild your muscle tissues after intense workout. Exercises exhaust the muscle’s energy stores and also cause tiny harm to the muscle tissues. So in the recovery stage, you need Carbohydrates and Creatine foods or supplements to restore the loss glycogen and phosphocreatine supply. Also you need Amino acids to enable the protein synthesis that repairs the broken muscular tissue that would lead to the development of bigger muscle mass fibers.
3. Ample Rest
This factor is needed to help the muscles repair themselves bigger and stronger.
To conclude, you need to stick to your regular exercise schedule and train harder every time to reach your bodybuilding goals. Look out for many subsequent articles on my website for lots of weight training advises and tips.