Research suggests that bodyweight training can build muscle effectively "independent of an external load". Key advantages include:

: Programs include various difficulty ratings, making them suitable for beginners while still challenging for advanced athletes. Specific Exercises & Programming

Effective bodyweight programs often focus on fundamental movements that can be progressed as strength increases. Bodyweight Strength Training Anatomy eBook - Amazon.com

: Exercises can be performed anywhere (home, hotel, work) and require little to no expensive equipment.