The effect of hypoxic exercises using an altitude training mask on the strength and extensibility of the respiratory muscles to call for physical effort among young soccer players. RJSS [Internet]. 2026 Apr. 15 [cited 2026 Jun. 24];29(90):30-43. Available from: https://rsprs.uomosul.edu.iq/index.php/rsprs/article/view/62565