The aim of this study was to investigate local muscle oxygen consumption (mVO2) during various protocols of isometric handgrip exercise. mVO2was measured by near-infrared spectroscopy (NIRS) during sustained, rhythmic, and intermittent isometric handgrip exercise. Whereas rhythmic handgrip exercise has the advantage that local muscle metabolism can be measured over the full range from low- to high-intensity work, the advantage of sustained handgrip exercise is that it is less prone to movement artifacts. Intermittent isometric handgrip exercise enables calculation of mVO2 at short time intervals providing information about the time response of local oxygen consumption in relation to the onset of exercise. Ten healthy subjects participated in this study. The different protocols were performed on separate days and in random order. mVO2 during rhythmic exercise was significantly higher than that during sustained exercise at all work intensities tested (P ≤ 0.05). However, the highest oxygen consumption value for the three exercise protocols was measured during the steady state of intermittent exercise (P ≤ 0.05). These results show that the measurement of task-specific muscle metabolism during exercise can be measured noninvasively and with relative ease by near-infrared spectroscopy. © (2003) COPYRIGHT SPIE–The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.