This chapter delves into the critical role of oxygen metabolism in skeletal muscles during dynamic exercise, emphasizing the importance of efficient oxygen supply to sustain muscle activity, particularly during high-intensity efforts. The study employs Near-Infrared Spectroscopy (NIRS), a non-invasive technology, to measure concentration changes of oxygenated, deoxygenated, and total hemoglobin in muscle tissues. This approach provides valuable insights into the oxygen supply-demand balance under varying exercise intensities. The research focuses on the medial gastrocnemius muscles of healthy subjects, using NIRS to record oxygen metabolism changes during short-duration, high-intensity exercises. The findings reveal significant differences in oxygen utilization between the first and second exercise sessions, highlighting the impact of post-exercise effects on muscle oxygen metabolism. The study also categorizes oxygen metabolism characteristics into increased, stable, and decreased total hemoglobin trends, with the majority of participants exhibiting an increase in blood flow during the second exercise. This chapter offers a comprehensive analysis of NIRS data, discussing the implications for monitoring peripheral arterial occlusion disease and the importance of careful measurement site selection and muscle preparation for accurate assessments. The detailed methodology and insightful discussions make this a compelling read for those interested in the intricacies of muscle oxygen dynamics and the application of NIRS technology in exercise physiology.