Contribution of Double Legs Speed Hops and Pull Down Resistance Bands Training to the 50 Meter Breaststroke Swimming Speed of Male K.U II Athletes at the Medan Aquatic Swimming Club in 2023. JIAS [Internet]. 24 Februari 2024 [dikutip 20 Maret 2026];1(1):1-12. Tersedia pada: https://jurnal.unimed.ac.id/2012/index.php/jias/article/view/51719