Festiawan, Rifqi, Suharjana Suharjana, Galih Priyambada, and Yudha Febrianta. “High-Intensity Interval Training Dan Fartlek Training: Pengaruhnya Terhadap Tingkat VO2 Max”. Jurnal Keolahragaan 8, no. 1 (April 30, 2020): 9–20. Accessed July 1, 2025. https://journal.uny.ac.id/index.php/jolahraga/article/view/31076.