You can eat egg whites before and after exercise, but you should pay attention to a time, preferably at least one and a half hours before exercise and about 30 minutes after exercise. Egg white is a good source of protein, which is very helpful for us to gain muscle and lose fat, but we should pay attention to a quantity problem. The protein content of an egg white is about 3 grams, but a bodybuilder should supplement at least 2 grams of protein per kilogram of body weight every day to achieve the purpose of repairing muscles. An average person weighs about 70 kilograms, so the egg white to be ingested is about 40, so we should also supplement our protein with other sources from protein, and if possible, we can appropriately ingest egg yolk. Many people think that excessive intake of egg yolk will increase cholesterol, but this is not the case. Many high-level athletes only eat about 2 egg yolks every day because of their high calories, so we ordinary people eat 2 to 3 whole eggs every day. In addition, many people reject protein powder because of misunderstanding. Protein powder is the most convenient source in protein, and there is no hormone as expected. Supplementing protein powder 20 to 30 minutes after exercise can make our body absorb it quickly. If we eat meat or protein, our absorption will be slower. Moreover, there is casein in the protein powder, which is a kind of slow-release protein and is usually taken before going to bed. Protein in milk is mostly casein, but the content of protein in milk is about 3%. It is convenient, fast and efficient to take protein powder.