Don't think that only the meal after fitness is useful. Every meal will be useful for 2-3 days. So what you should pursue is the daily intake of protein.
When your basic diet can meet protein's total intake of1.5 ~ 2g. You can start thinking about taking protein powder.
In addition, the diet should be determined according to the training level. If you improve your diet by one grade, your muscles will increase by one grade. Fitness needs to be done step by step. For the first 1.2 months, just eat 1 and 2 eggs every day. After 3 months, increase some meat intake and slowly start to increase food intake. Old Yin Jiahai wishes you a happy Dragon Boat Festival.