Pereira Hugo M, Larson Rebecca D, Bemben Debra A
Department of Health and Exercise Science, The University of Oklahoma, Norman, OK, United States.
Front Physiol. 2020 Jun 26;11:517. doi: 10.3389/fphys.2020.00517. eCollection 2020.
Estrogen and progesterone have distinct concentrations across the menstrual cycle, each one promoting several physiological alterations other than preparing the uterus for pregnancy. Whether these physiological alterations can influence motor output during a fatiguing contraction is the goal of this review, with an emphasis on the obtained effect sizes. Studies on this topic frequently attempt to report if there is a statistically significant difference in fatigability between the follicular and luteal phases of the menstrual cycle. Although the significant difference (the -value) can inform the probability of the event, it does not indicate the magnitude of it. We also investigated whether the type of task performed (e.g., isometric vs. dynamic) can further influence the magnitude by which exercise-induced fatigue changes with fluctuations in the concentration of ovarian hormones. We retrieved experimental studies in eumenorrheic women published between 1975 and 2019. The initial search yielded 921 studies, and after manual refinement, 46 experimental studies that reported metrics of motor output in both the follicular and luteal phases of the menstrual cycle were included. From these retrieved studies, 15 showed a statistical difference between the luteal and follicular phases (seven showing less fatigability during the luteal phase and eight during the follicular phase). The effect size was not consistent across studies and with a large range (-6.77; 1.61, favoring the luteal and follicular phase, respectively). The inconsistencies across studies may be a consequence of the differences in the limb used during the fatiguing contraction (upper vs. lower extremity), the type of contraction (isometric vs. dynamic), the muscle mass engaged (single limb vs. full body), and the techniques used to define the menstrual cycle phase (e.g., serum concentration vs. reported day of menses). Further studies are required to determine the effects of a regular menstrual cycle phase on the exercise-induced fatigability.
雌激素和孕激素在整个月经周期中的浓度各不相同，它们除了使子宫为怀孕做好准备外，还会引发多种生理变化。本综述旨在探讨这些生理变化是否会影响疲劳收缩期间的运动输出，并重点关注所获得的效应大小。关于这一主题的研究常常试图报告月经周期的卵泡期和黄体期之间在疲劳性方面是否存在统计学上的显著差异。虽然显著差异（p值）可以说明该事件发生的概率，但它并未表明差异的大小。我们还研究了所执行任务的类型（例如，等长收缩与动态收缩）是否会进一步影响运动诱导疲劳随卵巢激素浓度波动而变化的程度。我们检索了1975年至2019年间发表的关于月经周期正常女性的实验研究。初步检索得到921项研究，经过人工筛选后，纳入了46项报告了月经周期卵泡期和黄体期运动输出指标的实验研究。在这些检索到的研究中，有15项显示黄体期和卵泡期之间存在统计学差异（7项显示黄体期疲劳性较低，8项显示卵泡期疲劳性较低）。效应大小在各项研究中并不一致，范围很大（分别为-6.77；1.61，有利于黄体期和卵泡期）。研究结果不一致可能是由于疲劳收缩时使用的肢体不同（上肢与下肢）、收缩类型（等长收缩与动态收缩）、参与的肌肉量（单肢与全身）以及用于定义月经周期阶段的技术（例如，血清浓度与报告的月经日）存在差异。需要进一步的研究来确定正常月经周期阶段对运动诱导疲劳性的影响。
