Protein is really needed for muscle synthesis, but drinking protein powder before going to bed will increase the burden on the kidneys. Protein powder needs to be supplemented by bodybuilders. Such people spend a lot. For people who usually aim at fitness, we only need to ensure one or two eggs a day and eat enough meat to fully meet the protein needs of fitness. Don't be fooled by the so-called personal training in the gym. They sell protein powder on commission!