Mainly to supplement protein. Therefore, in terms of diet, eating more foods with high content of protein, such as chicken breast, beef and some vegetables, such as broccoli, is a better fitness supplementary food. However, it is not enough to get muscle growth from food alone. We can consider getting enough nutrition from special fitness supplement protein powder or muscle gain powder. In addition, after practicing well, the body will feel pain. In addition to massage to accelerate the decomposition of lactic acid in muscles, another time-saving method is to take BCAA, an amino acid that can prevent muscle decomposition and relieve muscle soreness. It is essential for fitness people. Beginners need these two supplements at present.