Consistent, and progressive muscular training is the best way to increase muscle size(also known as hypertrophy) and strength). It’s also important to understand that building and sustaining muscle requires energy. Your body will not build additional muscle mass unless your caloric intake can sustain more muscle mass. If you are committed to increasing muscle mass, it is worth considering working with a registered dietitian to review the number of calories and distribution of macronutrients in your diet. Adequate nutrition combined with muscular training will help you build and maintain more muscle.