Weight training needs correct technique. An excellent guide to muscle gaining is the course by Jason Ferrugia. It’s called Muscle Gaining Secrets and guides both beginners and others through a muscle-building program. When done the right way strength training helps in building muscles and strength. Incorrect technique leads to injuries, strains and muscle tears.
Learn the right way to do weight training. If need be take the help of a professional trainer or coach. There are many theories to muscle gaining and each is conflicting with the other. It is recommended by experts that one set of 12 reps done with the right weight is enough to do wonders to your muscles and body.