Heru S. Lesmana, Patrick Rodrigues, Lydia L. Simpson, Kyohei Marume, Dean R. Perkins, Justin S. Lawley
Exercise training improves maximum aerobic capacity, in part, through improvements in skeletal muscle function. This study aimed to investigate adaptations to improved aerobic capacity training through non-invasive and non-exhaustive tests of hyperemic muscle blood flow and near-infrared spectroscopy (NIRS) muscle oxygenation kinetics. An experimental study was conducted on 18 participants (age, 28.2 ± 5.3 yr; absVO2max, 3.60 ± 0.67 L·min−1). Before and after the intervention of a 6-week of high-intensity interval training (HIIT), participants underwent three tests: (1) a graded cardiopulmonary exercise test; (2) a vascular occlusion test; and (3) a steady-state exercise (SSE) at 60% of PPO. Expired gas analysis, superficial femoral blood flow (occlusion test only) and SmO2 kinetics were measured. The intervention increased maximal aerobic capacity absVO2max (p < 0.001, d = 0.65) and PPO (p < 0.001; d = 0.41). Moreover, steady-state absVO2 (p = 0.006; d = 0.37) and HR (p = 0.001; d = 0.65) were reduced. With the cuff test, the SmO2 desaturation slope increased (p = 0.04; d = 0.52), while peak muscle blood flow (p = 0.02; d = 0.51) and the SmO2 10 s reoxygenation rate increased (p < 0.001 d = 1.11; 0.74 ± 0.28 to 1.17 ± 0.45%/s). During steady-state exercise, SmO2 decreased less (p = 0.02; d = 0.43), and the 10s recovery kinetics rate was slowed (p = 0.01 d = 0.30; 0.28 ± 0.20 to 0.22 ± 0.21%/s). The improvement in VO2max had a moderate correlation with the SmO2 recovery rate post-steady-state exercise (p = 0.05, r = −0.54). HIIT changed maximal aerobic capacity alongside improvements in skeletal muscle hyperemic blood flow, SmO2 post-occlusive reactive hyperemia and SmO2 post-exercise recovery kinetics. Thus, the findings indicated that non-invasive and non-exhaustive hemodynamic kinetic profiles can monitor adaptations to improved aerobic capacity. © 2026 by the authors.
Department of Sport Science, University of Innsbruck, Innsbruck, 6020, Austria; Department of Sport Coaching, Universitas Negeri Padang, Padang, 25132, Indonesia; Division of Health, School of Sport and Human Movement, University of Waikato, Hamilton, 3240, New Zealand; School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, BS8 1QU, United Kingdom; Department of Cardiovascular, National Cerebral and Cardiovascular Center, Suita, 564-0018, Japan; Doctock Co., Ltd., Tokyo, 107-0062, Japan; Institute of Mountain Emergency Medicine, Eurac Research, Bolzano, 39100, Italy
