Diet: Meat, fish, milk, beans and eggs are rich in protein, and protein is needed for muscle building. You can eat more of these foods for three meals; You can take the method of eating less and eating more meals, and you can't eat too much per meal. The interval between exercise and diet should be 30 minutes to 1 hour, and the absorption after 30 minutes of exercise is better than usual. If it is inconvenient to eat at ordinary times, you can have some protein powder or muscle powder (thin people are more suitable to eat muscle powder to gain weight first). You can eat one or two spoonfuls of muscle gain powder or protein powder 30 minutes after exercise.