A person who follows a rigorous exercise routine and eats a healthy diet with adequate protein intake can begin seeing initial muscle gain in approximately four weeks. If significant gain in muscle mass is the goal, expect to see these results in six months to a year.
Individuals build muscle at varying rates based on their muscle structure and overall build, the consistency with which they perform muscle-building exercises and the intensity of their workouts. Diet and adequate protein intake also play a role in building muscle. Adequate rest between intense workouts gives torn muscle tissue time to repair, which facilitates muscle growth.