To gain muscle is to eat enough, but don't eat too much before exercise, because after eating enough, the blood is concentrated in the digestive tract. At this time, the heavy load of impedance training will lead to blood flowing to muscles, which is easy to indigestion for a long time. In the second stage, the muscle blood supply is insufficient and the exercise effect is not very good.

Generally speaking, muscle training is impedance training in fasting and semi-fasting (not full but not hungry) States, and then quickly replenish energy to improve blood sugar levels. So look at those muscular boxers in the gym. Many of them are like picnics after practice, with fruits, bread and drinks (made of protein powder) available.