Figure 4. Adaptive responses of O₂ pulse (V̇O₂/HR), ventilation (V̇_E), first and second ventilatory threshold (VT₁ and VT₂) to high-intensity interval training using anaerobic speed reserve (HIIT_ASR), HIIT using finial velocity during 30-15_IFT test (HIITv_IFT), and HIIT using maximal aerobic speed (HIIT_MAS). Triangles indicate individual percent change from baseline (X-axes) and horizontal bars represent mean group response. †  Denotes significantly different versus pre-training (p ≤ 0.05).