## 4 Discussion
### Practical Applications  
The findings of this study have several practical implications for sports training and performance optimization, as well as for coaches and practitioners managing mental fatigue. Here are some specific examples and recommendations based on the study's results:  
* Training Program Design: Coaches can incorporate high-intensity interval training (HIIT) sessions into training programs while considering the potential impact of mental fatigue. It is important to avoid scheduling HIIT sessions close to competitions, as they may induce physical and mental fatigue. By carefully planning the timing of HIIT sessions, coaches can ensure that athletes have adequate recovery time and perform at their best during important events;
* Cognitive Task Integration: Introducing a cognitively demanding task, such as the Stroop task, during recovery periods of HIIT can induce mental fatigue in athletes. This information can be utilized to design training sessions that specifically target mental fatigue resistance. Coaches can incorporate cognitive tasks strategically to challenge athletes' mental resilience and improve their ability to sustain focus and performance under mentally fatiguing conditions;
* Subjective Perception Monitoring: Coaches and practitioners should pay attention to athletes' subjective perceptions of fatigue, both physical and mental, during HIIT sessions. Monitoring the subjective feelings of fatigue can provide valuable insights into athletes' readiness and help adjust training intensity and volume accordingly. Athletes' feedback on their perceived effort, fatigue, and mood state should be taken into account when modifying training programs to optimize performance outcomes;
* Motivational Strategies: Coaches can explore the role of motivation as a moderator in the relationship between mental fatigue and physical performance. Implementing motivational strategies, such as goal setting, positive reinforcement, and creating a supportive training environment, may help counteract the negative effects of increased mental fatigue on physical performance. By fostering motivation, coaches can potentially enhance athletes' ability to maintain high levels of performance despite experiencing mental fatigue;
* Individualized Approach: It is essential to recognize that athletes may respond differently to mental fatigue. Future studies could explore individual differences in the relationship between mental fatigue, perceived effort, and performance outcomes. Coaches and practitioners can consider tailoring training programs and interventions based on athletes' unique characteristics, such as their psychological profiles and capacity to cope with mental fatigue. This individualized approach can maximize training effectiveness and support athletes' overall well-being.  
By implementing these practical applications, coaches and practitioners can optimize training programs, manage mental fatigue, and enhance athletes' performance outcomes. The study's findings provide valuable insights into the complex interaction between mental fatigue and physical performance, opening avenues for further research and the development of evidence-based strategies in sports training and performance.