Muscle growth, clinically referred to as hypertrophy, doesn't result from exercise alone. Proper and sufficient caloric intake, rest and repetition of the training cycle are also mandatory. Additional factors such as body type, gender, and age also need to be taken into consideration when embarking upon an exercise program to build muscle mass.
Failure Is A Good Thing
It's commonly known that exercises performed to fatigue, in sets with lower repetitions and heavier weight, induce muscle growth. Anecdotal data and empirical research now indicate that working out to fatigue with moderate to light weights will also stimulate muscle growth.
Mix It Up
Some debate whether to do split routines, such as targeting lower body parts, or total body workouts. It's perfectly safe to do both. Data increasingly suggests that greater results are achieved if both types of workouts are performed. Compound movements such as lunges, squats, dead lifts, and presses can be integrated into total body routines. Both approaches require adequate rest time and appropriate nutritional intake.
Sufficient rest and nutrition are just as important as the workouts. Proper protein and carbohydrate intake is required before and after the workout. Avoid excessive intake of calories from sources such as alcohol. Your age, gender and body type will influence the amount of caloric intake require and the rate of muscle gain.