Increased destruction of red blood cells can lead to anemia. During exercise, the spleen releases lysolecithin, which increases the fragility of red blood cells and weakens the resistance of red blood cell membrane. In addition, the blood flow accelerates during exercise, and violent collisions occur between red blood cells and between red blood cells and blood vessel walls, leading to the rupture and hemolysis of red blood cells, which leads to exercise anemia.

Secondly, insufficient intake and increased consumption of protein and iron can also lead to anemia. During exercise, the metabolism is vigorous, muscle growth increases protein's demand, while sweating during exercise increases iron excretion, so if there is not enough protein and iron supplement in food, the lack of protein and iron in the body will affect the production of hemoglobin, thus causing sports anemia.