This study utilized Near-Infrared Spectroscopy (NIRS) to assess the oxygen metabolism characteristics of lower limb skeletal muscles during ankle pumping exercises, simulating short-duration, high-intensity dynamic exercise. Four NIRS probes were used to simultaneously measure the bilateral medial gastrocnemius muscles. Data were collected from 20 healthy subjects over two sessions of ankle pumping exercises, including measurements of oxygenated, deoxygenated, and total hemoglobin. The results showed that oxygen metabolism during the second exercise session (2.24 ± 0.88 µM) was consistently higher than during the first (26.56 ± 14.36 µM), likely due to a post-exercise effect. During the second session, the blood flow response in the medial gastrocnemius was classified into three distinct metabolic patterns: an increase, stabilization, or decrease in total hemoglobin levels. Among these, an increase in total hemoglobin during exercise was the most common, observed in 64% of cases, possibly resulting from endothelial-related vasodilation induced by exercise. The variations in NIRS measurements within the same muscle are hypothesized to be due to the differing compositions of arteries, veins, and microvessels through which the light passes. Therefore, when using NIRS to evaluate dynamic tissue oxygen metabolism and hemodynamic physiological responses, careful consideration should be given to factors such as the measurement location within the muscle, the initial state of the muscle tissue, the warm-up duration and intensity before exercise, and the baseline metabolic characteristics prior to the exercise session.