Reproducibility of Muscle Oxygen Saturation

• Published in: International journal of sports medicine 2011-04, Vol.32 (4), p.277-280
• Main Authors: Thiel, C., Vogt, L., Himmelreich, H., Hübscher, M., Banzer, W.
• Format: Article
• Language: English
• Subjects: Adult; Bicycling - physiology; Biological and medical sciences; Calorimetry, Indirect - methods; Exercise Test; Female; Fundamental and applied biological sciences. Psychology; Humans; Male; Muscle, Skeletal - physiology; Oxygen - metabolism; Oxygen Consumption - physiology; Reproducibility of Results; Spectroscopy, Near-Infrared - methods; Training & Testing; Vertebrates: body movement. Posture. Locomotion. Flight. Swimming. Physical exercise. Rest. Sports; Young Adult
• ISSN: 0172-4622; 1439-3964
• DOI: 10.1055/s-0030-1269922

Abstract The present study evaluated the reproducibility of tissue oxygenation in relation to oxygen consumption (VO 2 ) across cycle exercise intensities in a test-retest design. 12 subjects (25.7±2.1 years; 24.7±1.9 kg · m −2 ) twice performed an incremental bicycle exercise protocol, while tissue oxygen saturation (StO 2 ) in the vastus lateralis muscle was monitored by a commercially available NIRS unit and VO 2 determined by an open-circuit indirect calorimetric system. Coefficients of variation across rest, workloads corresponding to 25, 50 and 75% of individual maximum capacity, and maximum load were 5.8, 4.6, 6.1, 8.0, 11.0% (StO 2 ) and 7.6, 6.0, 3.7, 3.4, 3.1% (VO 2 ), respectively. 95 % CI of relative test-retest differences ranged from −5.6 to +5.4% at 25% load to −17.2 to +7.5% at maximum load for StO 2 and from −7.3 to +7.7% at rest to −3.3 to +3.2% at maximum load for VO 2 . With advancing exercise intensity, within-subject variability of StO 2 was augmented, whereas VO 2 variability slightly attenuated. NIRS measurements at higher workloads need to be interpreted with caution.