The most efficient way to build muscle mass involves a combination of strength training, proper nutrition, and rest. A focus on compound exercises, such as squats, deadlifts, and bench presses, allows for training multiple muscle groups effectively. Aim for progressive overload by gradually increasing the weight or intensity of your workouts. Nutrition plays a critical role; ensure adequate protein intake to promote muscle repair and growth. Lastly, allow time for recovery, as muscles need rest to grow. Tailoring these components creates an optimal environment for muscle development.