Non-uniform quadriceps O2 consumption revealed by near infrared multi-point measurements

Single location muscle monitoring does not reflect the heterogeneous activation of the muscle group(s) during a given exercise. Vastus lateralis and rectus femoris O2 consumption (VO2) was investigated, noninvasively, at rest and during maximal voluntary contractions (MVC) using a 12-channel near-infrared continuous wave spectroscopy (NIRCWS) system (0.1 s acquisition time). VO2 either at rest or during MVC was found to be nonuniform in the 11 out of 12 measurement sites over a surface of 8 × 8 cm2. As expected, VO2 during exercise was significantly higher than VO2 at rest (P < 0.01). However, at each muscle measurement site no difference was found between the mean values (n = 12) of VO2 measured during a 5-s intermittent MVC and the VO2 values measured during 30-s continuous MVC (P = 0.25). These results strengthen the role of NIRCWS as a powerful tool for investigating the spatial and temporal features of muscle oxygenation changes as well as muscle VO2.

Single location muscle monitoring does not reflect the heterogeneous activation of the muscle group(s) during a given exercise. Vastus lateralis and rectus femoris O2 consumption (VO2) was investigated, non-invasively, at rest and during maximal voluntary contractions (MVC) using a 12-channel near-infrared continuous wave spectroscopy (NIRcws) system (0.1 s acquisition time). VO2 either at rest or during MVC was found to be nonuniform in the 11 out of 12 measurement sites over a surface of 8 × 8 cm2. As expected, VO2 during exercise was significantly higher than VO2 at rest (P < 0.01). However, at each muscle measurement site no difference was found between the mean values (n = 12) of VO2 measured during a 5-s intermittent MVC and the VO2 values measured during 30-s continuous MVC (P = 0.25). These results strengthen the role of NIRcws as a powerful tool for investigating the spatial and temporal features of muscle oxygenation changes as well as muscle VO2. © 2001 Academic Press.