Figure 2. Overview of the experimental protocol. IET, incremental exercise test; MSS, maximal sprint speed; IFT, 30-15 incremental fitness test. HIITASR, high-intensity interval training using anaerobic speed reserve (ASR); HIITvIFT, HIIT using finial velocity during 30-15IFT test (VIFT); HIITMAS, HIIT using maximal aerobic speed (MAS).