Effects of interval and fartlek training on VO₂max across leg muscle endurance levels

Hakim Irwandi Marpaung (Universitas Cenderawasih)
Evi Sinaga (Universitas Cenderawasih)
Ilham Ilham (Universitas Negeri Padang)
Kurdi Kurdi (Universitas Cenderawasih)
Ipa Sari Kardi (Universitas Cenderawasih)
Ansar Ansar (Universitas Cenderawasih)
Irfan Deny Oktavian (Universitas Cenderawasih)

Jurnal Penelitian Pendidikan Indonesia
Vol. 12 No. 1 (2026): JPPI (Jurnal Penelitian Pendidikan Indonesia)

This study aimed to compare the effects of interval and fartlek training on VO₂max improvement across different levels of leg muscle endurance. Twenty sports science students participated in a 2 × 2 factorial experiment, VO₂max and leg muscle endurance were assessed using the Multistage Fitness Test and Wall Sit Test, respectively. Data were analyzed using two-way ANOVA. Training method significantly affected VO₂max improvement (F = 21.443, p < .001), as did leg muscle endurance level (F = 160.105, p < .001). However, the interaction between the two factors was not significant (F = 3.905, p = .066). Interval and fartlek training produced different VO₂max adaptations, while leg muscle endurance was independently associated with VO₂max improvement; however, no significant interaction between the two factors was detected.