How much rest are you giving your muscles between training them? Did you know muscle protein synthesis is elevated up to 72 hours following a training session on a certain muscle group. This means your muscles are craving protein to repair and grow stronger. It is also craving Essential Amino Acids that you get from consuming BCAAs which are building blocks of protein. Your muscles need a stimulus to grow, so they need to be broken down every 3 days in order to grow and rebuild. Progressive overload and frequency are the two most important factors when building muscle, which means you need to train your muscles regularly to stimulate growth.
Be sure to allow your muscles enough time to rest, overworking the muscle isn't good either and training them every day will not promote growth.