Near-infrared spectroscopy (NIRS) could allow insights into controversial issues related to blood lactate concentration ([La] b ) increases at submaximal workloads (w˙). We combined, on five well-trained subjects [mountain climbers; peak O 2 consumption (V˙o 2peak ), 51.0 ± 4.2 (SD) ml ⋅ kg −1 ⋅ …