Muscle Oxygen Saturation Measurement in Male Collegiate Basketball Players

Lucas Beltran, Craig Horswill, PhD


The MOXY device provides a non-invasive measure of muscle oxygen saturation (SmO2) during exercise. Using near-infrared spectroscopy (NIRS), MOXY may help determine which physiological system limits physical performance by providing real time readings of SmO2.  Purpose: The aim of this preliminary study was to generate a hypothesis by evaluating patterns between muscle oxygen saturation (SmO2) and VO2max as well as anaerobic threshold (AT) during a progressive workload running test on the treadmill.  Methods: As a part of pre-season fitness assessment, college-age basketball players (n=8; mean ± SD: Wt: 92.7 ± 12.3kg; Ht: 191.4 ± 5.8cm) performed a progressive workload running test on the treadmill until volitional exhaustion. The treadmill slope increased every 2 min.  Before the treadmill test, the MOXY device was placed on either the right quadriceps, right calf, or right triceps muscles.  The triceps site was used in one subject as a reference of less active muscle not directly involved in the motion while whole body VO2 increased with progressive work. Main Outcome Measures: VO2max and AT were measured using indirect calorimetry. SmO2 was measured using the MOXY device. VO2max and AT values were compared with the slope of the relationship between log of VO2 and log of SmO2. Pearson correlation coefficients were generated for VO2max and the slope and AT and the slope.  Results: The correlation between VO2max and the slope was 0.516 (p>0.05), while the correlation between AT and the slope was 0.547 (p>0.05). Interpretations: It cannot be concluded that subjects with a higher VO2max and AT can predict the decline in SmO2. However, a future study with at least 15 subjects might be able to detect a relationship between these variables, and allow us to hypothesize that muscle oxygenation may be a limiting factor in maximum oxygen uptake during exercise.