# Performance-Determining Variables of a Simulated Skimo
## 4 Discussion
[45] only found a non-significant correlation between relative VO2 max and simulated sprint performance. The authors contended that, within a homogenous group of elite cross-country skiers, aerobic capacity establishes a foundational role, with neuromuscular characteristics such as Vmax assuming greater significance for success in sprint competitions. This interpretation may elucidate the lower correlation coefficients between VO2 max and performance in the final, as the physiological indices of the participants were more homogenous than with all participants included in time-trial, quarterfinal, and semifinal. In contrast to observations in cross-country sprint skiing, where aerobic capacity tends to play a progressively influential role in subsequent heats [12; 14; 46], our study did not identify a growing correlation between VO2 max and sprint performance as the Skimo competition unfolded. The absence of an escalating correlation strength throughout the competition may be attributed to the near-perfect correlations already evident from the initial runs. Notably, the individual trials in Skimo, especially the prolonged uphill sections, surpass the duration of those in traditional cross-country skiing. This extended duration likely constrains speeds to levels well within the aerobic system's capacity, setting it apart from the shorter, more intense bursts typically encountered in cross-country sprint skiing. Despite this distinctive dynamic, the emerging correlation between sub-maximal gross efficiency and performance from the individual time trial to the final. This echoes patterns documented in prior literature, suggests an increasing significance of VO2 max as the Skimo sprint competition advances. This observation suggests a nuanced interplay between sub-maximal gross efficiency and the evolving demands of the competition format, highlighting the potential for VO2 max to become even more important as the sprint competition progresses. In accordance with the robust correlation observed for VO2 max, Vmax also demonstrated very large correlation coefficients with performance in skimo sprint competitions. These findings highlight the general importance of the ability to generate high maximal speed and extends upon the existing body of literature, encompassing both skimo (particularly in vertical races) [6] and cross-country sprint skiing [43; 45; 47] across various terrains, including flat and uphill sections [43]. The generation of high velocities is influenced by cardiovascular factors, as well as neuromuscular and anaerobic characteristics [48; 49; 50; 51]. Accordingly, it has been suggested that the maximal velocity achieved during cross-country skiing diagonal striding may be limited not only by energy systems, but also by the rate of force development [52]. This is due to reported stride durations of approximately 200 ms per leg. During the simulated competition, the cycle duration lasted for approximately 800 ms, resulting in a stride duration of below 400 ms per leg. Although Skimo allows for a longer duration of force generation, the neuromuscular ability to produce the largest possible ground reaction force within short ground contact times may still limit skiing velocity. These results are further supported by the moderate to large correlations observed with strength measures, particularly highlighting the importance of lower body strength. Additionally, the increasing correlations found between \(\mathrm{VLA_{max}}\) and superior performance in the finals reinforce the hypothesis that the relationship between \(\mathrm{V_{max}}\) and the ability to sustain speed in sprint competitions may indicate a heightened anaerobic capacity [17; 45; 53]. While the previous literature emphasized the substantial role of anaerobic capacity, constituting approximately 20-30% of total energy expenditure during maximal efforts in cross-country sprint skiing [15; 54; 55], the present study underscores the pronounced significance of the aerobic energy system in Skimo sprint performance.