“the The effect of Oregon circuit training and Tabata on increasing VO2Max in male junior karate athletes at Tako Dojo Kodim 0206 Dairi in 2025: eng”, Compet. J. Pendidik. Kepelatihan Olahraga, vol. 17, no. 3, pp. 2771–2779, Oct. 2025, doi: 10.26858/cjpko.v17i3.402.