## 3 Results  
There were significant differences in the maximum speed achieved in the test according to the phase of the menstrual cycle (X\({}_{2}\)= 9.5; \(p\) = 0.009; \(\eta^{2}\) = 0.16), with the median being significantly higher in the follicular phase (around day 10) (Mn = 10.6; IQ = 5.7) than in the luteal phase (around day 21) (Mn = 10.0; IQ = 4.9) (\(Z=-3.1\); \(p\) = 0.002) and slightly higher than in the bleeding phase (around days 2,3) (Mn = 10.5; IQ = 5.7) (\(Z=-2.2\); \(p\) = 0.031). No significant differences were found in comparisons between the luteal phase and the bleeding phase. There were not differences in shock (G) depending on the phase of the menstrual cycle (F\({}_{2}\) = 2.59; \(p\) = 0.11, \(\eta^{2}\) = 0.27), with higher shock in the bleeding phase and lower shock in the luteal phase (Table 1). Test intensity had a significant effect on shock (F\({}_{3}\) = 8.87; \(p\) = 0.01, \(\eta^{2}\) = 0.56). Pairwise comparisons with Bonferroni adjustment showed they were significantly higher at 80% than the rest, and higher at 100% than at 50% (Figure 1). The interaction between menstrual phase and test intensity had a significant effect (F\({}_{3}\) = 8.87; \(p\) = 0.01, \(\eta^{2}\) = 0.29), which was significantly higher at 50% in the bleeding phase than in the follicular and luteal phases. The menstrual phase had no effect on braking (G) (F\({}_{2}\) = 0.24; \(p\) = 0.89, \(\eta^{2}\) = 0.03), although the values were slightly higher during the bleeding phase. On the other hand, test intensity did have a significant effect (F\({}_{6}\) = 2.91; \(p\) = 0.018, \(\eta^{2}\) = 0.43). It was significantly higher at 80% and 100% than at 50%. The menstrual phase did not affect the peak vertical ground reaction force (F(Bw)) (F\({}_{2}\) = 0.624; \(p\) = 0.55, \(\eta^{2}\) = 0.08), which was slightly higher in the bleeding phase. On the other hand, test intensity did have a significant effect (F\({}_{3}\) = 21.92 \(p\) < 0.001, \(\eta^{2}\) = 0.76), significantly higher at 80% and 100% than at 50%, and higher at 80% than at 60%. The menstrual phase did not influence vertical force rate (N/kg/s) (F\({}_{2}\) = 1.95 \(p\) = 0.18, \(\eta^{2}\) = 0.22) nor horizontal force rate (N/kg/s) (F\({}_{2}\) = 0.469; \(p\) = 0.55, \(\eta^{2}\) = 0.06), which was slightly higher in the bleeding phase. On the other hand, test intensity had a significant effect on vertical force rate (F\({}_{3}\) = 32.48 \(p\) < 0.001, \(\eta^{2}\) = 0.82): it was significantly higher at 80% than the rest and at higher at 100% than at 60% and 50%. In addition, the intensity of the test also had a significant effect on the rate of horizontal force (F\({}_{3}\) = 7.61 \(p\) = 0.025, \(\eta^{2}\) = 0.52); it was highest at 100%, and significantly higher at 80% than at 60% and 50%. The menstrual phase did not influence the swing force rate (N/kg/s) (F\({}_{2}\) = 0.125; \(p\) = 0.88, \(\eta^{2}\) = 0.02), which was slightly higher during the bleeding phase. On the other hand, test intensity did have a significant effect on swing force rate (F\({}_{3}\) = 10.14 \(p\) = 0.012, \(\eta^{2}\) = 0.59): it was highest at 100%, and significantly higher at 80% than at 60% and 50%. Neither menstrual phase nor test intensity had a significant effect on total force rate (N/kg/s). The menstrual phase had a significant influence on vertical spring stiffness (kN/m) (X\({}_{2}\)\({}^{2}\) = 15; \(p\) < 0.001; \(\eta^{2}\) = 0.25), with the median being significantly higher in the follicular phase (17.4) than in the luteal phase (16.0) (Z = -3.7; \(p\) < 0.001). On the other hand, test intensity had a significant effect on vertical spring stiffness (F\({}_{3}\) = 2.95 \(p\) = 0.124, \(\eta^{2}\) = 0.297), which was highest at 50%, followed by 100%. Neither the menstrual phase nor test intensity had a significant effect on leg spring stiffness (kN/m). The menstrual phase had no influence on power (w) (F\({}_{2}\) = 1.97 \(p\) = 0.18, \(\eta^{2}\) = 0.25), although it was slightly higher during the bleeding phase.