Purpose <p>This study aimed to investigate the effects of sprint interval training with voluntary hypoventilation (VHL) on aerobic and anaerobic energy metabolism in young men.</p> Methods <p>Fourteen healthy male university students were randomly assigned to a normal breathing group (CON, n = 7) or a VHL group (n = 7). Both groups performed repeated sprint training for three weeks. Pre- and Post-training, we assessed maximal oxygen uptake (VO₂max) as an index of aerobic capacity, and maximal accumulated oxygen deficit (MAOD) and repeated sprint ability (RSA) as indices of anaerobic energy metabolism, together with VO₂, oxygen pulse, and arterial oxygen saturation (SpO₂) during the RSA test.</p> Results <p>During training, SpO₂ transiently decreased in the VHL group. After the three-week intervention, VO₂max increased significantly in the VHL group, whereas no significant change was observed in the CON group. During the RSA test, oxygen pulse and VO₂ during the later sprint repetitions were also higher post-training in the VHL group only, while MAOD did not change in either group.</p> Conclusions <p>Sprint interval training with VHL enhanced oxidative metabolism through improvements in VO₂max and oxygen pulse, thereby supporting sustained performance during repeated sprints. However, anaerobic metabolic capacity (MAOD) did not improve within the short training period. As VHL requires no altitude exposure or artificial hypoxic devices, it may serve as a practical and accessible training strategy.</p>