The effect of an eight-week HIIT programme on the performance outputs of 14-16 year old basketball players training programme's impact on some performance outputs

The statistical analysis of the data obtained in the research was carried out using JAMOVI software. The normality of the data distribution was tested using the Shapiro Wilk test, and it was determined that the data were normally distributed. To determine within-group changes, the Paired Samples T-Test was applied. The findings indicated that the implemented training program led to significant and effective improvements in the variables of 20-meter sprint, fatigue index, vertical jump, push-up, squat endurance, Yo-Yo intermittent recovery test, and indirectly calculated maximal oxygen consumption (VO₂max). In conclusion, the results demonstrated that the high-intensity interval training protocol improved general performance levels and had a positive and significant impact on key motor abilities such as speed, endurance, explosive strength, and muscular endurance. These findings are largely consistent with similar studies in the literature and indicate that high-intensity interval training is an effective training method that can enhance multiple performance parameters in a relatively short period. However, it should be noted that the effectiveness of the protocol may vary depending on factors such as the duration and content of the program and its suitability for the specific characteristics of the sport. These factors must be taken into consideration during training planning. Keywords: High-Intensity Interval Training, Basketball, Physical Performanc