You can eat after working out because after exercise, muscle cells are activated and in an anabolic period that lasts about 1 to 2 hours. This period is a critical time to replenish nutrition, providing sufficient protein and carbohydrates can accelerate anabolism, promote muscle repair and increase muscle mass. If protein and carbohydrates are not provided after exercise, anabolism in the organism can be converted into catabolism and consume muscle, so it is necessary to eat after exercise.