## 4 Discussion
### Reactive Agility and Downhill Performance  
One of the main findings of the research was the correlation between aspects of reactive agility and performance during downhill trail running. When analysing inter-session variables, it was found that performance on the mountain (Total Time) was positivelycorrelated with times in the 15 m linear sprint, 5 m linear sprint, and reactive agility reaction time with sport-specific stimulus.  
The correlation with the linear sprint at 5 and 15 m appeared to confirm that runners with higher acceleration capacity in the reactive agility test finished the trail running test in a shorter time. It is logical to think that in a downhill section, it is necessary to decelerate and accelerate again on many occasions either to change direction or to maintain balance and equilibrium depending on the route and type of terrain.  
On the other hand, the correlation found between the RAsp reaction time (reactive agility with sport-specific stimulus) and the total time of the trail running descent coincides with the findings reported by [PERSON] [32], who established a relationship between performance in trail running descents and high visual perception abilities, which are important parts of the RAsp test. It also coincides with studies carried out in team sports, where it has been shown that the capacity for visual perception and reaction capacity significantly differentiates the level of athletes [23].  
However, the lack of correlation found between performance during downhill running and the RAge test leads us to believe that the use of sport-specific images (instead of a numerical stimulus) during the training/assessment of reactive agility is decisive in improving performance in these athletes. By using non-specific stimuli, several important perceptual and decision-making components, such as pattern recognition and visual scanning ability, which are fundamental in trail running, are excluded. Therefore, by not assessing these key aspects, it is understandable that no significant correlation was found between the RAge test and performance in trail running descents. This is in agreement with several authors who found no differences between athletes when using a generic stimulus such as a light but found differences when using a sport-specific stimulus in reactive agility tests [33].  
Another interesting aspect was that the RAsp reaction time was found to be related to the cadence and contact times. Runners who had better reaction times in the test increased cadence with shorter contact times in the downhill and ultimately performed better in the test. In their research, [PERSON] et al. [9] found that leg stiffness was one of the determinants of trail running descents; furthermore, we know from [PERSON]'s research [34] that leg stiffness is largely determined by running contact times, so we can infer that runners reducing their contact times were improving leg stiffness and consequently improving one of the determinants of performance.  
Some authors [35] have suggested that more experienced trail runners and those who reach higher speeds adopt a more forefoot-midfoot stride pattern, as do some experienced track and dirt road runners. In the present investigation, no significant correlation was found between the stride pattern and running performance. This may be due to the fact that in our research, we used only the average of the whole test as a variable. [PERSON] et al. [36] showed how during a trail run, the gait pattern changes constantly according to the terrain and the slope even in the best trail runner in the world, so it would be more appropriate to perform an analysis of the gait pattern continuously during the race and not just an average, as it may not reflect the complete strategy of the runner.