This research aimed: To identify the effect of a hypoxic interval training program on cardiorespiratory fitness, some physical variables, and the level of skillful performance of squash players. The researchers used the experimental method due to its suitability for the type and nature of this research through the experimental design using the pre and post measurements for one experimental group. Al-Shams Al-Athlete numbered (6) players, bringing the total sample to (16) players. The researchers used measurements of cardiorespiratory fitness, physical tests, and the level of skillful performance as a means of data collection. The extracted data were processed with appropriate statistical treatments, including the arithmetic mean, standard deviation, median, skewness coefficient, significance of differences test (T), simple correlation coefficient (Pearson), and improvement rates. Among the most important results: The hypoxic interval training program for 8 weeks has a positive effect on cardiorespiratory fitness, represented in the improvement in physiological measurements (pulse at rest and after exertion, cardiac impulse, hemoglobin, blood oxygen saturation, maximum oxygen consumption, vital capacity). , pulmonary ventilation, normal breathing volume, inspiratory reserve volume, expiratory reserve volume, inspiratory capacity) for the squash players, the research sample, the proposed hypoxic interval training program had a positive effect on the physical variables and the level of skillful performance of the squash players, the research sample.