Wheelchair Tennis is a dynamic sport that necessitates a blend of speed, agility, quickness, strength, power, and endurance. An athlete not only requires these attributes but also must maintain a high-performance level throughout an extended season. Consequently, adjustments in programming are essential to enhance cardiorespiratory capacity, upper-body strength, and agility proficiency in a manner that incorporates intermittent features. One viable approach is the utilization of high-intensity interval training (HIIT) methodology. Consequently, the aim of this research was to evaluate the alterations in cardiorespiratory fitness, musculoskeletal strength, and agility proficiency among wheelchair tennis athletes following a HIIT regimen. The study involved 30 wheelchair tennis players with spinal cord injuries aged between 19 and 28 years. They were divided into an experimental group, which participated in a HIIT program [EG, n = 15], and a control group, which adhered to a standard training regimen [CG, n = 15]. All participants underwent anthropometric assessments, the wheelchair yo-yo test, and hand grip evaluation. The results displayed a significant Time x Group interaction for the yo-yo test and hand grip evaluation, indicating a marked improvement in the intervention group (p < 0.001). Conversely, no substantial changes were observed in the control group. Therefore, it could be claimed that that the inclusion of a HIIT protocol in the daily training regime leads to a significant positive influence on the cardiorespiratory fitness, musculoskeletal strength, and agility capabilities of wheelchair tennis players.