The use of hypoxic exercises in terms of the concentration of lactic acid in the blood to develop speed endurance and the completion of a 200-meter run. cbej [Internet]. 2022 Dec. 14 [cited 2024 Jul. 20];21(91):873-96. Available from: https://cbej.uomustansiriyah.edu.iq/index.php/cbej/article/view/7376