## 1 Introduction  
Currently, in sports sciences, sensors using non-invasive near-infrared spectroscopy (NIRS) technology are employed to measure muscle oxygen saturation (SmO\({}_{2}\)), defined as the ratio of oxygenated hemoglobin (O\({}_{2}\)Hb) to total hemoglobin (tHb) (SmO\({}_{2}\) = O\({}_{2}\)Hb \(\div\) tHb \(\times\) 100%) [1]. SmO\({}_{2}\) can be evaluated during exercise, and over the past decade, its assessment at rest has attracted researchers, allowing for the study of muscle metabolism through a vascular occlusion test (VOT) without requiring physical exertion [2; 3]. A VOT shows how the muscle desaturates and resaturates after oxygen deprivation, indicating how muscle oxygen is utilized and recovered [4]. One of the primary objectives of a VOT is to identify \"reactive hyperemia\", a physiological phenomenon where blood flow temporarily increases following a brief interruption, which is useful for detecting endothelial capacity deficiencies [5]. A VOT-NIRS has demonstrated a slower oxygen recovery rate and a lower reactive hyperemia response in diseased populations compared to healthy subjects [6; 7; 8; 9]. Additionally, the kinetics of muscle reoxygenation during a VOT describe the speed at which a muscle reoxygenates after ischemia and the restoration of blood flow, indicating non-invasively skeletal muscle oxidative capacity [10]. Recently, VOT protocols have been suggested as an important tool for determining sports performance [11; 12] since they allow for the examination of muscle adaptations from a metabolic perspective [2]. However, few researchers use VOT-NIRS to identify performance improvements, partly due to the numerous methodologies and lack of consensus on data collection. It is important to highlight that the timing of VOT-NIRS measurements can cause variations in SmO\({}_{2}\) for athletes. For example, exercise-induced acute fatigue can destabilize muscle oxygen transport [13]. It has been described that female footballers do not return to stable SmO\({}_{2}\) levels after an official match [13], and faster reoxygenation kinetics of resting SmO\({}_{2}\) has been associated with severe injury risk compared to controls in footballers [14]. However, it was a short VOT (30 s) that allowed for the identification of adaptations to training [15]. Additionally, SmO\({}_{2}\) dynamics, such as desaturation and resaturation, have been related to the power of a countermovement jump (CMJ) before and 24 h post-exercise [12]. CMJ performance decreased 24 h after the match due to neuromuscular fatigue and was related to SmO\({}_{2}\) at rest [12; 13]. SmO\({}_{2}\) measured with VOT-NIRS has the potential to track improvements in muscle oxidative capacity over prolonged training periods (i.e., six months) [2]. Most studies use VOT-NIRS at rest without prior exercise, which causes acute fatigue. Conversely, other studies have assessed post-exercise VOT-NIRS after a time trial and have identified a correlation with VO\({}_{2}\)max [16]. Additionally, resting SmO\({}_{2}\) showed better predictive power for performance (92.7%) compared to other variables such as power, heart rate (HR), and VO\({}_{2}\)max, which are metrics widely used in endurance sports [16]. However, when a VOT-NIRS was conducted on separate days without the influence of prior exercise, no relationship with VO\({}_{2}\)max was found [17]. In contrast, [PERSON] et al. [11] found a correlation between resting oxygen consumption and VO\({}_{2}\)max in tests conducted on separate days without prior exercise influence, but this relationship was only observed in the vastus lateralis (VL) muscle and not in the gastrocnemius muscle, causing controversy among researchers. VOT-NIRS protocols have differences in application times, and researchers should consider this to be a possible interference in the results due to increased blood flow resulting from post-exercise or acute fatigue [18]. Based on the above, other studies have suggested a 30 min rest period to allow blood flow to return to resting conditions [19].