From a scientific point of view, muscles will begin to grow at the beginning of fitness, but it usually takes more than a month to see the effect. The specific time depends on personal situation and exercise intensity. The key to muscle building is to have enough strength and replenish enough protein. Drinking some protein powder after fitness at ordinary times is conducive to better muscle gain. Protein powder can be bought online, PQfitness. We should also pay attention to rest and combine work and rest.