Muscle Performance During the Menstrual Cycle Correlates With Psychological Well-Being, but Not Fluctuations in Sex Hormones

Tine Vrist Dam; Line Barner Dalgaard; Vassilis Sevdalis; Bomartin Bibby; Xanne Janse De Jonge; Claus H. Gravholt; Mette Hansen

Disclosures

Med Sci Sports Exerc. 2022;54(10):1678-1689. 

In This Article

Abstract and Introduction

Abstract

Purpose: We aimed to study variations in strength and power performance during the menstrual cycle (MC) in eumenorrheic young women and during the pill cycle in oral contraceptives (OC) users.

Methods: Forty healthy, normal-weight women between 18 and 35 yr (n = 30 eumenorrheic women; n = 10 OC users) completed this prospective cohort study. Seven to nine times during the MC/pill-cycle, the participants completed a physical performance test series, a questionnaire about psychological well-being, blood sampling, and determination of body mass. The physical tests included isometric handgrip strength, elbow flexor strength, countermovement jump (CMJ) height, and a 10-s Wingate bike test.

Results: No direct correlation was observed between the variations in sex hormones and physical performance parameters. However, positive correlations were observed between physical performance outcomes and self-reported motivation, perception of own physical performance level, pleasure level, and arousal level. CMJ was 6% lower in the late luteal phase (LL) compared with the midluteal phase (ML) (P = 0.04). Wingate peak power was 3% lower in early follicular (EF) compared with the ML (P = 0.04). Furthermore, Wingate average power was 2%–5% lower in LL compared with all other MC phases. In line with these observations, physical pain was higher in EF and LL, and the pleasure level was lower in EF compared with the other MC phases. In OC users, we observed no variation in performance and self-reported parameters between the placebo-pill phase and the OC-pill phase.

Conclusions: Impairments in CMJ and Wingate performance were observed at the end and start of MC compared with other MC phases, which were associated with lower psychological well-being, but not the sex hormone fluctuations.

Introduction

The primary function of the female sex hormones is to regulate fertility and thereby reproduction. However, research has suggested that the sex hormones, specifically estrogen, positively influence cardiovascular, respiratory, neuromuscular, neurocognitive, and metabolic parameters and thereby physical performance.[1,2] In female elite athletes, a minor difference in performance (<5%) related to the menstrual cycle (MC) will be of great importance during competition.

Variation in performance during the MC has been evaluated in a meta-analysis by McNulty et al..[3] This meta-analysis included 78 studies in which 1193 women had their performance tested during the MC. However, 53 studies (68%) were of low or very low quality, and only 6 studies (8%) were classified as being of high quality. Therefore, the authors concluded that current evidence does not permit any strong conclusion concerning variation in physical performance during the MC, and future studies of higher quality are needed. Another recent systematic review by Blagrove et al.[4] came to a similar conclusion. Studies that have investigated the effect of the MC on performance parameters in women have either reported no significant difference in strength performance during the MC[5–12] or greater muscle strength just before ovulation.[13–15] The lack of consensus could be due to methodological differences and limitations in the individual studies.[16] Particularly, the methods used to identify the MC phases vary between studies, including measurement of body temperature, self-reported calendar counting, use of urinary ovulation tests, and analyses of sex hormone levels in saliva or blood.[4] Measurement of sex hormones is essential for confirmation of MC phases, but has not been performed in several of the previous studies.[13,14,17] In the majority of studies, the number of participants has been <20,[5–14] and the number of test days completed during an MC has been ≤3.[5–10,12] Furthermore, including trained women as participants may create bias through prior training sessions in the days leading up to the testing confounding the results, as well as increasing the incidence of suppressed female sex hormone levels and irregular MC.[18,19] If women presenting with an anovulatory or irregular MC are included in the data analysis, the likelihood of detecting a variation in performance during the MC is reduced. Therefore, even though research performed specifically in trained women is essential in perspective to performance optimization, it is relevant to test untrained women as a starting point because performance in this population may be less confounded by previous exercise training and menstrual dysfunction.

The mechanistic basis for the MC influencing muscular performance is derived from animal studies showing that estrogen is important for the actin–myosin binding and may thereby influence muscle strength.[20] Compared with estrogen, the current knowledge surrounding the impact of progesterone on muscle strength is sparse. However, studies have suggested an antagonistic effect of progesterone on estrogen's actions.[21] Furthermore, animal findings indicate that progesterone has a potentially inhibiting effect on neural activity[22] and seems to antagonize the stimulating effect of estrogen on contraction-stimulated glucose uptake during short, high-intensity exercise.[23]

Psychological well-being is reported to vary during the MC,[24] which may also influence physical performance. Just before the menstrual bleeding and in the beginning of the bleeding period, pain and headaches are commonly reported in female athletes from a range of sport disciplines[25,26] and in nonathletes.[27] This may negatively impact physical performance, but to our knowledge, no one has investigated the correlation between physical performance and changes in psychological parameters during the MC.

More than 100 million women use oral contraceptives (OC) worldwide today[28] as birth control, but also to control menstrual bleeding and alleviate pain and discomfort related to the MC.[29] A recent systematic review investigated the impact of OC use on physical performance in the OC-pill and placebo-pill phase, and observed no difference between phases,[30] which is in line with the use of OC result in a more stable sex hormonal profile. Nevertheless, the latter review also highlighted the need for further high-quality studies because most of the limited research carried out in this field was shown to be of low quality.

The purpose of the present study was to investigate if muscular strength in young eumenorrheic women varies 1) with fluctuations in sex hormones during an MC and 2) between defined MC phases. In addition, we aimed to examine the relationship between physical performance and the participants' self-reported psychological well-being during an MC. Finally, we aimed to elucidate if muscular strength differed between the OC-pill phase and the placebo-pill phase in OC users.

We hypothesized that eumenorrheic women would perform better around ovulation when the estrogen/progesterone ratio is highest compared with the other MC phases, whereas lower self-reported well-being around the menstrual bleeding period would diminish the physical performance. In addition, we hypothesized that performance would not differ between the OC-pill and placebo-pill phases in OC users. Still, the latter is important to clarify in perspective to future studies including OC users who have their physical performance tested.

processing....