## 4 Discussion  
The aim of this study was to investigate the acute effects of the FIFA 11+ and Harmoknee warm-up protocols, known for their injury prevention effects in female football players, on physical performance (flexibility, vertical jump, and shooting speed). To this end, the FIFA 11+ and Harmoknee warm-up protocols were applied to the participants at 48 h intervals, and their acute effects on flexibility, vertical jump, and shooting speed measurements were investigated and compared. When the warm-up protocols were compared, it was observed that the FIFA 11+ warm-up protocol had a statistically significant impact on vertical jump compared to the Harmoknee protocol among female football players (\(p\) = 0.04). No statistically significant difference was found between the FIFA 11+ and Harmoknee protocols on flexibility and shooting speed test values (\(p\) > 0.05). When the correlation analysis between physical parameters and performance tests was conducted, it was concluded that the relationship between vertical jump and height, height and body weight, and BMI and height were statistically significant (\(p\) < 0.05). An examination of the literature highlights diverse findings regarding the impact of warm-up protocols on flexibility. In a study by [PERSON] et al. [40], no significant difference in flexibility (sit-and-reach) between the experimental and control groups was found when pre-test and post-test values were compared, where a 10-week FIFA 11+ warm-up program was performed. In their research on young football players, [PERSON] et al. [41] found that 4 weeks of FIFA 11+ practice improved their flexibility. [PERSON] et al. [42] investigated the acute effects of the FIFA 11+ warm-up protocol and concluded that it had a positive impact on flexibility. In their study, [PERSON] et al. [43] found that among child football players of different age groups, the FIFA 11+ and the Harmoknee warm-up had positive acute effects on flexibility. [PERSON] et al. [44] and [PERSON] et al. [45] found that the FIFA 11+ protocol produced a significant difference in flexibility between experimental and control groups. [PERSON] et al. [46] reported that the dynamic stretching and polyometric  
Figure 5: Vertical jump scatterplots and box-plots of participants according to FIFA 11+ and Harmoknee warm-up protocols. Figure 6: Shooting speed scatterplots and box-plots of participants according to FIFA 11+ and Harmoknee warm-up protocols. movements included in the FIFA 11+ protocol aim to develop ROM (range of motion) and flexibility, positively affecting overall athletic performance. In their study on young female football players, [PERSON] et al. [25] indicated that the FIFA 11+ protocol had no significant effect on flexibility. It is suggested that this finding may be ascribed to the age and gender characteristics of the subjects. The literature presents conflicting results regarding the FIFA 11+ protocol's effect on flexibility, and fewer studies have focused on the Harmoknee protocol, indicating the need for further research in this area. [PERSON] et al. [17] found positive effects on the vertical jump in 12 male soccer players after 9 weeks of practicing FIFA 11+. In a study by [PERSON] et al. [47], a significant increase in vertical jump and agility was observed in the FIFA 11+ group after 4 weeks of training. In the research conducted by [PERSON] et al. [48] on 36 elite male football players, the athletes were divided into three groups: FIFA 11+, Harmoknee, and dynamic warm-up programs. As a result of 24 sessions of the warm-up program applied 3 days a week for 8 weeks, a significant increase was observed in athletes' jump heights in the FIFA 11+ and Harmoknee groups. (FIFA 11+: \(p\) = 0.000, Harmoknee: \(p\) = 0.002). No similar increase was found in the dynamic warm-up group. [PERSON] et al. [27] found no statistically significant difference in jump performance between the FIFA 11+ and dynamic warm-up protocols. [PERSON] et al. [49] investigated the acute effects of the FIFA 11+, Harmoknee, and dynamic warm-up protocols.