## 3 Results
On the other hand, test intensity had a significant effect on power (F\({}_{3}\) = 16.05 \(p\) = 0.003, \(\eta^{2}\) = 0.73): it was (significantly) highest at 80%, and higher at 100% than at 60% and 50%. As regards physiological variables, the following were analyzed: lactate (mmol/L), lactate recovery after the maximal test, and maximum and average heart rate (bpm). The results are shown below in relation to the phases of the menstrual cycle (Figure 3) and test intensity (Figure 4). The menstrual phase made no significant difference on lactate (mmol/L) (F\({}_{2}\) = 1.3; \(p\) = 0.339 \(\eta^{2}\) = 0.30), although it was lower during the bleeding phase (Figure 3). However, test intensity did have a significant effect (F\({}_{3}\) = 12.87; \(p\) < 0.024, \(\eta^{2}\) = 0.81). Post hoc comparisons with Bonferroni adjustment showed no significant differences and LSD tests performed were significantly higher at 100% and 80% than at 50% and 60% (Figure 2). The resting time after the maximal test showed a tendency to have a significant effect (F\({}_{3}\) = 2.44; \(p\) = 0.80, \(\eta^{2}\) = 0.096) on accumulated lactate, with the lowest lactate value observed immediately after the end of the test. Lactate accumulates until it reaches the maximum value at minute 3 after the test, and then progressively decreases at minute 5 and 7 after the test, but it fails to reach the value observed immediately after the end of the test (Figure 2). Figure 1: Comparison of the effect of test intensity on running kinetic variables. \({}^{\circ}\) Indicates significant differences (\(p\) < 0.05 adjusted Bonferroni) with test intensity at 100%. \({}^{\bullet}\) Indicates significant differences (\(p\) < 0.05 adjusted Bonferroni) with test intensity at 80%. \({}^{\bullet}\) Indicates significant differences (\(p\) < 0.05 adjusted Bonferroni) with test intensity at 60%. \({}^{\bullet}\) Indicates significant differences (\(p\) < 0.05 adjusted Bonferroni) with test intensity at 50%. In the maximal running test, the menstrual phase showed a tendency to influence lactate recovery (Figure 3). In all cases, the highest lactate value was observed in the follicular phase, which tended to be significantly higher than in the bleeding phase after 1 min of recovery (F\({}_{2}\) = 1.81; \(p\) = 0.20, \(\eta^{2}\) = 0.21), and also higher in the follicular phase than in the luteal phase after 5 min of recovery (F\({}_{2}\) = 1.9; \(p\) = 0.186, \(\eta^{2}\) = 0.21). The menstrual phase had a significant influence on peak heart rate (bpm) (F\({}_{2}\) = 4.92; \(p\) = 0.028; \(\eta^{2}\) = 0.45), which was significantly higher in the follicular phase than in the bleeding and luteal phases (Figure 4). Likewise, test intensity had a significant effect as well (F\({}_{3}\) = 107.9; \(p\) < 0.001; \(\eta^{2}\) = 0.94); heart rate increased with test intensity, with the exception of the comparison between 60% and 50%, where the differences were not significant (Figure 4). The menstrual phase had an influence on average heart rate (bpm) (F\({}_{2}\) = 5.5; \(p\) = 0.020; \(\eta^{2}\) = 0.48) (Figure 4). The post hoc least significant difference (LSD) comparisons were significantly higher in the follicular phase than in the bleeding phase and in the luteal phase, although pairwise comparisons with Bonferroni adjustment showed no significant differences. On the other hand, test intensity had a significant effect (F\({}_{3}\) = 46.8; \(p\) < 0.001, \(\eta^{2}\) = 0.89): it was significantly higher at 80% compared to the rest, and significantly higher at 100% than at 60% and 50% (Figure 4). Finally, differences in fatigue scores depending on the phase of the menstrual cycle and the intensity of the test were also analyzed (Table 1). Regarding the menstrual phase, differences were found in the perceived fatigue score before the test (X22 = 3.8; \(p\) = 0.152), with the highest score found in the bleeding phase and the lowest in the follicular phase.