Figure 4. Adaptive responses of O2 pulse (V̇O2/HR), ventilation (V̇E), first and second ventilatory threshold (VT1 and VT2) to high-intensity interval training using anaerobic speed reserve (HIITASR), HIIT using finial velocity during 30-15IFT test (HIITvIFT), and HIIT using maximal aerobic speed (HIITMAS). 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).