use special exercises training Recurring manner according to the concentration of lactic acid in the blood and its impact in carrying your speed and accomplish ran 400 meters. jope [Internet]. 2015 Jun. 28 [cited 2024 Apr. 30];27(2):76-91. Available from: https://jcope.uobaghdad.edu.iq/index.php/jcope/article/view/575