If you want to gain muscle mass fast, Make sure to add enough supersets and rest 'n pause sets into your workout program
. This can be the most efficient technique to shock the muscles into maximal grow! I always do at the very least one superset and one rest 'n pause set in my every single training routine!
However it is critical to not overdo it, or else it could overload your muscles too much and the healing of the muscle will be misersble. In order to gain muscle mass, you have to train your muscle, not tear it.