Heru Syarli Lesmana, Ben Schroeder, Kyohei Marume, Patrick Rodrigues, Justin S. Lawley
The aim of this study was to validate previously developed equations to predict maximal oxygen uptake ((Formula presented.)) from near-infrared spectroscopy (NIRS) during and after a period of limb ischaemia. Moreover, NIRS recovery kinetics after steady-state exercise (SSE) could be used to monitor (Formula presented.) and exercise intensity thresholds. Seventeen healthy adults completed a 3 min 300 mmHg pressure cuff occlusion to measure the occlusion slope, relative rate of muscle reoxygenation at 10 s (Rep 10s), baseline (Rbl), peak (Rpeak) and area under the curve (AUC2min). SSE was performed at 100 W (SSE1) and 150 W (SSE2) to determine the relative rate of muscle reoxygenation (R1bl and R2bl). Thereafter, incremental maximal cycling was used to determine (Formula presented.), ventilatory thresholds (VTs) and gross efficiencies (GEs). The values of Rep 10s (r = 0.61, p = 0.02), Rbl (r = 0.53, p = 0.04), Rpeak (r = 0.60, p = 0.02), AUC2min (r = 0.67, p < 0.01) and occlusion slope (r = −0.68, p = 0.005) were correlated with absolute (Formula presented.). After steady-state cycling, SSE1 Rbl was correlated with absolute (Formula presented.) (r = 0.67, p = 0.01) and relative (Formula presented.) (r = 0.60, p = 0.02), in addition to absolute VT1 (r = 0.66, p = 0.01) and relative VT1 (r = 0.61 p = 0.02). The SSE2 Rbl was correlated with absolute (Formula presented.) (r = 0.58, p = 0.02), relative (Formula presented.) (r = 0.63, p = 0.02), absolute VT2 (r = 0.56, p = 0.03), relative VT2 (r = 0.62, p = 0.01) and GE2 (r = 0.56, p = 0.03). Using previously defined prediction equations, (Formula presented.) could be predicted with a modest degree of typical error (Rep 10s, 521 mL min−1; Rpeak, 525 mL min−1; slope, 393 mL min−1). NIRS kinetic profiles during or after a period of ischaemia or after SSE are related to (Formula presented.) and exercise intensity thresholds. Nonetheless, their predictive validity is limited to a broad estimate of the aerobic fitness of an individual. © 2025 The Author(s). Experimental Physiology published by John Wiley & Sons Ltd on behalf of The Physiological Society.
Department of Sport Science, University of Innsbruck, Innsbruck, Austria; Department of Sport Coaching, Universitas Negeri Padang, Padang, Indonesia; Department of Cardiovascular, National Cerebral and Cardiovascular Center, Suita, Japan; Division of Health, School of Sport and Human Movement, University of Waikato, Hamilton, New Zealand
