First of all, protein powder is not everything. Doesn't mean you can gain weight by eating protein powder and muscle powder. It is also possible that it will be lighter if you don't practice well. Even the best protein powder, muscle powder, creatine, etc. It's all fitness supplements! Since it is a tonic, it is to supplement the effect that you can't achieve with three meals a day. It is based on a normal diet of three meals a day. If your complementary food is not in place, protein powder alone is ineffective. Besides training, swimming is aerobic training, and aerobic training can't achieve the purpose of muscle gain. If you want to gain muscle by swimming, it is not easy to gain weight, and it depends on the time you swim. Aerobic exercise will consume your fat and muscles, which is a kind of weight loss exercise. A cup of protein powder alone is not enough to supply energy. Again, from the point of view of food supplement, if you used to eat two steamed buns at a time, I think you should be able to eat four steamed buns at a time after exercise. If you can't eat one meal, you can change three meals into five. Only when your diet keeps up can your weight change. If you consume more energy than you consume every day, you will only gain weight, otherwise you will only lose weight.