Heru Syarli Lesmana, Kyohei Marume, Justin S. Lawley
Measuring and monitoring individual cardiorespiratory fitness through a valid and accessible non-exhaustive surrogate is required. Techniques measuring haemodynamics have shown promise, and this study aimed to optimize the predictive validity of these approaches alongside developing predictive equations. In a two-study design, 8 (pilot study) and 30 (confirmation study) healthy adults completed exercise testing to assess maximal oxygen consumption ((Formula presented.)) and an ischaemic occlusion test on the upper thigh to assess superficial femoral blood flow from ultrasonography and skeletal muscle oxygenation (SmO2) by near-infrared spectroscopy (NIRS) before, during and post-cuff release. In study 1, treadmill running and a 5-min 220 mmHg ischaemic cuff pressure were performed, whereas in study 2, cycling ergometry and a 3-min 300 mmHg cuff pressure were applied. In study 1 and study 2, abs (Formula presented.) and rel (Formula presented.) were correlated to peak blood flow post-cuff occlusion (r = 0.57–0.84, all P < 0.01). In study 2, several NIRS based metrics of post-occlusive reactive hyperaemia were strongly correlated with abs (Formula presented.) and rel (Formula presented.) (all P < 0.001). Moreover, the magnitude of oxygen desaturation during the cuff occlusion was highly significantly related to both abs (Formula presented.) and rel (Formula presented.) (all P < 0.001). As an example, the SmO2 desaturation slope was strongly associated with abs (Formula presented.) (r = −0.74, P < 0.001). Finally, intercorrelations between the rate of SmO2 desaturation during cuff occlusion and the rate of SmO2 reoxygenation and peak skeletal muscle blood flow post-cuff occlusion were observed (P < 0.01). An ischaemic-based test of skeletal muscle haemodynamic profiles could potentially be used to predict (Formula presented.) and estimate a person's fitness. © 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
