Influence Of Menstrual Cycle Research Articles

Influence of menstrual cycle and oral contraceptive phases on strength performance, neuromuscular fatigue, and perceived exertion.

The primary aim of the study was to assess differences in strength performance, neuromuscular fatigue, and perceived exertion across phases of the menstrual cycle [MC; early follicular (eFP), late follicular (lFP), and mid-luteal phase (mLP)] and oral contraceptives [OCs; active pill phase (aPP) and nonactive pill phase (nPP)]. The secondary aim was to analyze the influence of fluctuating serum 17β-estradiol and progesterone concentrations on these parameters in naturally menstruating women. Thirty-four women (21 with a natural MC and 13 using OCs) completed three or two experimental sessions, respectively. Mean propulsive velocity (MPVmean) and total number of repetitions (REPtotal) were assessed during a power [3 × 8 at 60% 1RM (one-repetition maximum)] and hypertrophy squat loading (3 sets to failure at 70% 1RM), respectively. Changes in bench press and squat MPV at 60% 1RM in response to the loadings were used as surrogates for nonlocal and local fatigue, respectively. Total blood lactate accumulation (BLAA) and markers of perceived exertion were assessed in each session. No significant differences between any of the MC or OC phases were observed for MPVmean, REPtotal, nonlocal and local fatigue, and markers of perceived exertion (all P > 0.050). A higher intraindividual 17β-estradiol concentration was significantly associated with a lower MPVmean (P = 0.019). BLAA was significantly higher in the lFP than in the mLP (P = 0.019) and negatively associated with the intraindividual progesterone concentration (P = 0.005). Although 17β-estradiol may negatively influence the MPV, it appears that fluctuations of both sex hormones across the MC and OC phases are not prominent enough to induce significant or practically relevant changes in the assessed parameters.NEW & NOTEWORTHY Although a high intraindividual 17β-estradiol concentration was associated with a lower movement velocity, markers of strength performance and surrogates for nonlocal and local fatigue remained unaffected by MC and OC phases. Blood lactate accumulation was significantly reduced in the mLP. Furthermore, our findings suggest that the impact of the MC phases varies greatly among individuals. Individuals with high fluctuations in sex hormone concentrations may experience relevant changes in the assessed parameters.

The influence of menstrual phase on synaptic plasticity induced via intermittent theta-burst stimulation

BackgroundOvarian hormones influence the propensity for short-term plasticity induced by repetitive transcranial magnetic stimulation (rTMS). Estradiol appears to enhance the propensity for neural plasticity. It is currently unknown how progesterone influences short-term plasticity induced by rTMS. ObjectiveThe present research investigates whether the luteal versus follicular phase of the menstrual cycle influence short-term plasticity induced by intermittent theta-burst stimulation (iTBS). We tested the hypothesis that iTBS would increase motor evoked potentials (MEPs) during the follicular phase. Further, we explored the effects of the luteal phase on iTBS-induced neural plasticity. MethodTwenty-nine adult females participated in a placebo-controlled study that delivered real and sham iTBS to the left primary motor cortex in separate sessions corresponding to the follicular phase (real iTBS), luteal phase (real iTBS), and a randomly selected day (sham iTBS). Outcomes included corticospinal excitability as measured by the amplitude of MEPs and short-interval intracortical inhibition (SICI) recorded from the right first dorsal interosseous muscle before and following iTBS (612 pulses). ResultsMEP amplitude was increased following real iTBS during the follicular condition. No significant changes in MEP amplitude were observed during the luteal or sham visits. SICI was unchanged by iTBS irrespective of menstrual phase. ConclusionThese findings suggest women experience a variable propensity for iTBS-induced short-term plasticity across the menstrual cycle. This information is important for designing studies aiming to induce plasticity via rTMS in women.

Influence of Menstrual Cycle and Oral Contraceptive Phases on Bone (re)modelling Markers in Response to Interval Running

To explore how sex hormone fluctuations may affect bone metabolism, this study aimed to examine P1NP and β-CTX-1 concentrations across the menstrual and oral contraceptive (OC) cycle phases in response to running. 17β-oestradiol, progesterone, P1NP and β-CTX-1 were analysed pre- and post-exercise in eight eumenorrheic females in the early-follicular, late-follicular, and mid-luteal phases, while 8 OC users were evaluated during the withdrawal and active pill-taking phases. The running protocol consisted of 8 × 3min treadmill runs at 85% of maximal aerobic speed. 17β-oestradiol concentrations (pg·ml−1) were lower in early-follicular (47.22 ± 39.75) compared to late-follicular (304.95 ± 235.85;p = < 0.001) and mid-luteal phase (165.56 ± 80.6;p = 0.003) and higher in withdrawal (46.51 ± 44.09) compared to active pill-taking phase (10.88 ± 11.24;p < 0.001). Progesterone (ng·ml−1) was higher in mid-luteal (13.214 ± 4.926) compared to early-follicular (0.521 ± 0.365; p < 0.001) and late-follicular phase (1.677 ± 2.586;p < 0.001). In eumenorrheic females, P1NP concentrations (ng·ml−1) were higher in late-follicular (69.97 ± 17.84) compared to early-follicular (60.96 ± 16.64;p = 0.006;) and mid-luteal phase (59.122 ± 11.77;p = 0.002). β-CTX-1 concentrations (ng·ml−1) were lower in mid-luteal (0.376 ± 0.098) compared to late-follicular (0.496 ± 0.166; p = 0.001) and early-follicular phase (0.452 ± 0.148; p = 0.039). OC users showed higher post-exercise P1NP concentrations in withdrawal phase (61.75 ± 8.32) compared to post-exercise in active pill-taking phase (45.45 ± 6;p < 0.001). Comparing hormonal profiles, post-exercise P1NP concentrations were higher in early-follicular (66.91 ± 16.26;p < 0.001), late-follicular (80.66 ± 16.35;p < 0.001) and mid-luteal phases (64.57 ± 9.68;p = 0.002) to active pill-taking phase. These findings underscore the importance of studying exercising females with different ovarian hormone profiles, as changes in sex hormone concentrations affect bone metabolism in response to running, showing a higher post-exercise P1NP concentrations in all menstrual cycle phases compared with active pill-taking phase of the OC cycle.

Influence of menstrual cycle phase and oral contraceptive phase on exercise performance in endurance-trained females.

Limited data exists on the influence of menstrual cycle (MC) phase and oral contraceptive (OC) phase on physical performance in endurance-trained females due to poor control regarding MC verification and differentiation. We aimed to evaluate exercise performance and the respiratory response to exercise in three distinct phases of the MC and OC cycle in endurance-trained females. Using a prospective cohort study design, we recruited trained females (Vo<inf>2max</inf> 52±4 mL O<inf>2</inf>/min/kg) who were either not using oral contraceptives (NOC) or using monophasic OCs. NOC were tested in the early and late follicular phase (FP) and the mid-luteal phase (LP). OC-users were tested in the withdrawal phase (WP) and two times in the active OC phase (OCP). The test battery included DXA scans, blood sampling, a submaximal bike test, a maximal isometric knee-extensor strength test, 4 and 20-second bike sprints, and a 6 min time trial on a bike. MC phases were verified by the use of ovulation kits and circulating sex hormone levels. After the exclusion of four NOCs due to inadequate sex hormone levels, 11 NOC and 13 OC users were included in the final analysis. 6 min time trial performance, sprint performance, and most submaximal exercise intensity variables did not differ between MC phases and OC cycle phases. However, in NOC, ventilation (L/min) during exercise at 30% of aerobic peak power was 7.6% lower in the late FP compared to the LP (P<0.05). In OC users, muscle strength was 3.9% higher in the early OCP compared to WP (P<0.05), whereas body mass was higher in the late OCP compared to WP (P<0.05). Collectively, our study suggests that MC phase and OCP influence exercise performance to a limited extent in endurance-trained females.

Influence of Menstrual-Cycle Phase on Sleep and Recovery Following High- and Low-Intensity Training in Eumenorrheic Endurance-Trained Women: The Female Endurance Athlete Project.

To investigate the influence of menstrual-cycle (MC) phase on objective sleep and perceived recovery following high- (HIT) and low-intensity training (LIT) in endurance-trained women. Fifteen naturally menstruating, endurance-trained women completed standardized HIT and LIT sessions during the early follicularphase (EFP), ovulatoryphase (OP), and midluteal phase(MLP) of 2 MCs. Overnight sleep was monitored using a Somnofy sleep monitor after each training session, and perceived recovery was assessed after 24hours using self-report scales. MC phases were determined using the 3-step method, and noneumenorrheic MCs were retrospectively excluded from analysis. MC phase had a main effect on wake after sleep onset (P ≤ .001), with higher values in MLP (33[22]min) than EFP (22 [19] min, P = .043) and OP (14 [9] min, P = .001), sleep efficiency (P = .033), with lower values in MLP (87% [6%]) than OP (90% [8%], P = .047), and light sleep (P = .023) with higher values in MLP (59% [6%]) than EFP (54% [7%], P = .037). Session type had a main effect on perceived recovery (P < .018) and perceived muscle soreness (P = .007), indicating lower perceived recovery and higher perceived muscle soreness following HIT compared to LIT (P < .001, P = .018, respectively). No interactions were found between MC phase and session type for any of the measured variables. Objective sleep quality, but not perceived recovery, was influenced by MC phase, as indicated by small impairments to multiple indices of objective sleep during MLP. There were no interactions between MC phase and session type, indicating that the effect of MC on sleep and recovery is consistent regardless of session type.

The perceived influence of menstrual cycle and hormonal contraceptives on training and performance: Comparison between football, handball, and orienteering

Recently, we published self-reported data concerning the perceived effects of the menstrual cycle and hormonal contraceptives on the training and performance of 1086 female athletes participating in 57 sports. However, studies comparing differences between sports with large sample sizes are lacking. The aim of this ancillary study was to compare the impact of the menstrual cycle and hormonal contraceptives on training and performance between the three largest sports in the cohort, that is, football, handball, and orienteering, as well as the knowledge and support provided to the female athletes engaged in these sports. The results are from a web-based questionnaire completed by 312 football players, 243 handball players, and 93 orienteers. A total of 54% of the orienteers planned their training based on the menstrual cycle, which was a higher proportion compared to football (45%) and handball (29%) players ( p &lt; 0.05). Fewer football players believed that the menstrual cycle had an impact on their performance during training and competition compared to the two other sports. A high proportion of the athletes used hormonal contraceptives in all three sports, but a lower proportion of the orienteers (40%) used hormonal contraceptives compared to football (76%) and handball players (66%) ( p &lt; 0.05). Football and handball players received overall more support than orienteers, and the support was mostly provided by a physiotherapist and/or a strength and conditioner coach besides the main coach. These findings demonstrate that the perceived influence of the menstrual cycle and hormonal contraceptives on training and performance differs between endurance athletes in orienteering compared to team-sport athletes in football and handball.

The Influence of Menstrual-Cycle Phase on Measures of Recovery Status in Endurance Athletes: The Female Endurance Athlete Project.

To investigate the influence of menstrual-cycle (MC) phase on measures of recovery status, that is, resting heart rate, perceived sleep quality, and physical and mental readiness to train, among female endurance athletes. Daily data were recorded during 1 to 4 MCs (ie,duration ≥21 and ≤35d, ovulatory, luteal phase ≥10d) of 41 trained-to-elite-level female endurance athletes (mean [SD]: age 27 [8]y, weekly training: 9 [3]h). Resting heart rate was assessed daily using a standardized protocol, while perceived sleep quality and physical and mental readiness to train were assessed using a visual analog scale (1-10). Four MC phases (early follicular phase [EFP], late follicular phase, ovulatory phase, and midluteal phase [MLP]) were determined using the calendar-based counting method and urinary ovulation-prediction test. Data were analyzed using linear mixed-effects models. Resting heart rate was significantly higher in MLP (1.7beats·min-1, P = .006) compared with EFP without significant differences between the other MC phases. Perceived sleep quality was impaired in MLP compared with late follicular phase (-0.3, P = .035). Physical readiness to train was lower both in ovulatory phase (-0.6, P = .015) and MLP (-0.5, P = .026) compared with EFP. Mental readiness to train did not show any significant differences between MC phases (P > .05). Although significant, the findings had negligible to small effect sizes, indicating that MC phase is likely not the main determinant of changes in measures of recovery status but, rather, one of the many possible stressors.

The Menstrual Cycle's Influence on Sleep Duration and Cardiovascular Health: A Comprehensive Review.

The menstrual cycle, a fundamental biological process in women, extends its influence beyond reproduction, impacting sleep duration and cardiovascular health. This comprehensive review delves into the intricate connections that bind these three vital aspects of women's health. Beginning with thoroughly exploring the menstrual cycle, we uncover its phases and the dynamic hormonal fluctuations that underlie each stage. We pay special attention to estrogen and progesterone, the primary sex hormones orchestrating the menstrual cycle. With their rhythmic rise and fall, these hormones orchestrate events, affecting sleep duration, sleep patterns, and various indicators of cardiovascular well-being. The review examines how the menstrual cycle influences sleep patterns, exploring the nuanced changes in sleep duration observed throughout menstrual phases. We elucidate the contributing factors, encompassing hormonal fluctuations, the impact of pain and discomfort, and the significance of emotional and psychological factors. All of these elements collectively contribute to variations in sleep quality. Shifting our focus to the cardiovascular system, we investigate the bidirectional relationships between sleep disturbances and cardiovascular conditions, emphasizing the need to address sleep-related issues in the context of cardiovascular risk. The menstrual cycle is analyzed as a pivotal mediator in these intricate connections, exploring how hormonal fluctuations across menstrual phases can influence sleep patterns and cardiovascular health. This analysis provides valuable insights into the complex causality web. As clinical implications emerge, we emphasize the importance of tailoring healthcare strategies for individuals with irregular menstrual cycles. We explore potential interventions, from personalized care and hormone management to lifestyle adjustments, to improve sleep and cardiovascular well-being. In conclusion, this comprehensive review sheds light on the interplay between the menstrual cycle, sleep duration, and cardiovascular health. It underscores the urgent necessity for personalized healthcare approaches and preventive strategies, empowering women to navigate these intricate relationships. Ultimately, through a nuanced understanding of these interactions, we can work towards enhancing women's overall well-being and reducing cardiovascular risk within the context of menstrual cycle-related influences.

Sex and menstrual cycle influence human spatial navigation strategies and performance

Which facets of human spatial navigation do sex and menstrual cycle influence? To answer this question, a cross-sectional online study of reproductive age women and men was conducted in which participants were asked to demonstrate and self-report their spatial navigation skills and strategies. Participants self-reported their sex and current menstrual phase [early follicular (EF), late follicular/periovulatory (PO), and mid/late luteal (ML)], and completed a series of questionnaires and tasks measuring self-reported navigation strategy use, topographical memory, cognitive map formation, face recognition, and path integration. We found that sex influenced self-reported use of cognitive map- and scene-based strategies, face recognition, and path integration. Menstrual phase moderated the influence of sex: compared to men, women had better face recognition and worse path integration, but only during the PO phase; PO women were also better at path integration in the presence of a landmark compared to EF + ML women and men. These findings provide evidence that human spatial navigation varies with the menstrual cycle and suggest that sensitivity of the entorhinal cortex and longitudinal axis of the hippocampus to differential hormonal effects may account for this variation.

Influence of menstrual cycle and hormonal contraceptive use on MS symptom fluctuations: A pilot study.

In clinical practice, females with MS often report menstrually-related symptom fluctuations. Hypothetically, use of oral contraceptives (OCs) could reduce these fluctuations, particularly continuous OCs (11+ weeks of consistent exogenous hormones followed by 1 week placebo). To prospectively capture (1) whether neurologic and generalized symptoms vary with menstrual cycle phase and (2) whether type of contraception impacts symptom fluctuations. In this two-center pilot study, females with MS and a regular menstrual cycle prospectively tracked their menstrual cycles and completed symptom surveys for up to 6 months. Participants were categorized as 1) users of oral contraceptives, either a) cyclic or b) continuous, or 2) endogenously cycling, either c) hormonal intrauterine device (IUD) users or d) "none users" (e.g. no hormonal contraception; included condoms, copper IUD, tubal ligation, "fertility awareness methods"). There was no correction for multiple analyses. Altogether, 47/70 participants (67%) provided >4 weeks of data and were included in the analyses. Mean (SD) age was 35.0 (0.9) years, median (IQR) EDSS was 1.5 (1-2) and mean (SD) SymptoMScreen score was 10.4 (9.6). For endogenously cycling patients (IUD and none users), fatigue (MFIS) was lower in the perimenstrual period than in the luteal period (p<0.05). For continuous OC users, variability in symptoms was lower than for endogenously cycling females (MFIS: p<0.01; Daily Hassles, from Uplift & Hassles Survey: p<0.05) or cyclic OC users (MFIS: p<0.001). In this pilot study, symptom severity did not definitively fluctuate in relationship to the menstrual cycle in endogenously cycling participants. However, fatigue and daily hassles were less variable for participants using continuous OC than for cyclic OC users or no-OC users. Future confirmatory studies are warranted to further examine whether contraceptive choice can be leveraged to manage symptom fluctuation in cycling females with MS. Such studies could enroll larger cohorts over fewer cycles or employ incentivization and hormonal measurements to enhance participant retention and statistical power.

Self-perceived Menstrual Cycle Influence On Performance Among Female Distance Runners

Self-perceived Menstrual Cycle Influence On Performance Among Female Distance Runners

Investigating the circulating sphingolipidome response to a single high-intensity interval training session within healthy females and males in their twenties (SphingoHIIT): Protocol for a randomised controlled trial

Introduction: Growing scientific evidence indicates that sphingolipids predict cardiometabolic risk, independently of and beyond traditional biomarkers such as low-density lipoprotein cholesterol. To date, it remains largely unknown if and how exercise, a simple, low-cost, and patient-empowering modality to optimise cardiometabolic health, influences sphingolipid levels. The SphingoHIIT study aims to assess the response of circulating sphingolipid species to a single session of high-intensity interval training (HIIT). Methods: This single-centre randomised controlled trial (RCT) will last 11 days per participant and aim to include 32 young and healthy individuals aged 20-29 (50% females). Participants will be randomly allocated to the HIIT (n= 16) or control groups (physical rest, n= 16). Participants will self-sample fasted dried blood spots for three consecutive days before the intervention (HIIT versus rest) to determine baseline sphingolipid levels. Dried blood spots will also be collected at five time points (2, 15, 30, 60min, and 24h) following the intervention (HIIT versus rest). To minimise the dietary influence, participants will receive a standardised diet for four days, starting 24 hours before the first dried blood sampling. For females, interventions will be timed to fall within the early follicular phase to minimise the menstrual cycle's influence on sphingolipid levels. Finally, physical activity will be monitored for the whole study duration using a wrist accelerometer. Ethics and dissemination: The Ethics Committee of Northwest and Central Switzerland approved this protocol (ID 2022–00513). Findings will be disseminated in scientific journals and meetings. Trial Registration The trial was registered on www.clinicaltrials.gov (NCT05390866, https://clinicaltrials.gov/ct2/show/NCT05390866) on May 25, 2022.

Menstrual cycle influences on cue-induced smoking cravings and heart rate variability.

Women experience greater difficulties in quitting smoking than men, though the hormonal factors contributing to this sex difference remain to be clarified. The current study aimed to examine menstrual cycle effects on smoking cue-induced cravings as well as examine dynamic reproductive hormone change as a potential mediator underlying any cycle effects observed. Twenty-one women who smoke underwent two laboratory sessions - one in the mid-follicular phase and the other in the late luteal phase - involving an in-vivo smoking cue task, administered before and after exposure to a psychosocial laboratory stressor. Heart rate variability (HRV) and subjective smoking cravings were assessed in response to the cue task. The degree of change in the urinary metabolites of estradiol and progesterone from 2 days before to the day of each laboratory session was measured. Results revealed that both before and following exposure to psychosocial stress, highly nicotine-dependent women exhibited smaller cue-induced increases in HRV relative to the follicular phase. In contrast, less nicotine-dependent women exhibit an increase in HRV in both menstrual cycle phases. Results furthermore suggest that menstrual cycle effects seen in highly nicotine-dependent women are driven by the decline in estradiol and progesterone occurring in the late luteal phase. Though limited by a small sample size, this study suggests that withdrawal from reproductive hormones in the late luteal phase may alter highly nicotine-dependent women's physiological response to smoking cues, which may reflect greater difficulty resisting temptation. These findings may provide some insight regarding women's greater difficulty in maintaining abstinence after quitting smoking.

Influence of Menstrual Cycle on Internal and External Load in Professional Women Basketball Players

The menstrual cycle can be seen as a potential determinant of performance. This study aims to analyze the influence of the menstrual cycle in women on sports performance, more specifically on the internal and external load of professional women basketball players. The sample consisted of 16 women players and 14 training sessions were recorded. A descriptive analysis of the mean and standard deviation of the variables according to the different phases of the menstrual cycle was performed, as well as an ANCOVA, partial Eta2 effect size criteria, and Bonferroni's Post Hoc test to identify differences among phases. The results establish that ovulation is the phase in which higher values of external load are recorded and, therefore, the late follicular phase is the time of the cycle where a greater intensity in explosive distance, accelerations and decelerations are recorded. Considering women's hormonal cycles, understanding their function and the individual characteristics of each athlete is essential since it allows for the development of specific training, the prevention of injuries and therefore positively affects the performance of women players. To this end, individual training profiles should be created in specific contexts, not following general rules. In addition, psychological factors and the specific position of the athletes should be monitored.

The influence of menstrual cycle on the indexes of cortical excitability

The influence of menstrual cycle on the indexes of cortical excitability

Oral contraceptive use and menstrual cycle influence acute cerebrovascular response to standing.

To determine if the menstrual cycle and oral contraceptives (OC) influence responses to acute orthostatic stress and if these factors are clinically relevant to the diagnosis of initial orthostatic hypotension (iOH). Young, healthy women were recruited, including OC users (n=12) and non-users (NOC; n=9). Women were tested during the low hormone (LH; placebo pills; days 2-5 natural cycle) and high hormone (HH; active dose; days 18-24 natural cycle) menstrual phases. Changes in mean arterial pressure, cardiac output, heart rate, the 30:15 heart rate ratio and cerebrovascular resistance indices within 30s of standing were examined. There were no effects of OC or menstrual cycle on hemodynamic responses during standing (all p>0.05). In the LH phase, OC users had a greater fall in mean middle cerebral artery blood velocity (MCAV) compared to NOC (p<0.05). However, this was reversed in the HH phase, where OC users had a reduced fall in mean MCAV (p<0.05). Interestingly, 8 women (OC and NOC) had drops in systolic/diastolic blood pressure meeting the criteria for iOH, and 7 of those 8 women displayed this drop in a single phase of the menstrual cycle. Our results indicate that chronic versus acute OC use (i.e., long-term use observed via LH phase versus short-term use observed via HH phase) have opposing effects on cerebral blood velocity during standing. Further, our results highlight that multiple assessments across the cycle may be necessary to accurately diagnose iOH, as most women met the diagnostic criteria during a single menstrual phase.

Investigating the circulating sphingolipidome response to a single high-intensity interval training session within healthy females and males in their twenties (SphingoHIIT): Protocol for a randomised controlled trial

Introduction: Growing scientific evidence indicates that sphingolipids predict cardiometabolic risk, independently of and beyond traditional biomarkers such as low-density lipoprotein cholesterol. To date, it remains largely unknown if and how exercise, a simple, low-cost, and patient-empowering modality to optimise cardiometabolic health, influences sphingolipid levels. The SphingoHIIT study aims to assess the response of circulating sphingolipid species to a single session of high-intensity interval training (HIIT). Methods: This single-centre randomised controlled trial (RCT) will last 11 days per participant and aim to include 32 young and healthy individuals aged 20-29 (50% females). Participants will be randomly allocated to the HIIT (n= 16) or control groups (physical rest, n= 16). Participants will self-sample fasted dried blood spots for three consecutive days before the intervention (HIIT versus rest) to determine baseline sphingolipid levels. Dried blood spots will also be collected at five time points (2, 15, 30, 60min, and 24h) following the intervention (HIIT versus rest). To minimise the dietary influence, participants will receive a standardised diet for four days, starting 24 hours before the first dried blood sampling. For females, interventions will be timed to fall within the early follicular phase to minimise the menstrual cycle's influence on sphingolipid levels. Finally, physical activity will be monitored for the whole study duration using a wrist accelerometer. Ethics and dissemination: The Ethics Committee of Northwest and Central Switzerland approved this protocol (ID 2022–00513). Findings will be disseminated in scientific journals and meetings. Trial Registration The trial was registered on www.clinicaltrials.gov (NCT05390866, https://clinicaltrials.gov/ct2/show/NCT05390866) on May 25, 2022.

The Effect of Menstrual Cycle Phases on Approach-Avoidance Behaviors in Women: Evidence from Conscious and Unconscious Processes.

The menstrual cycle affects women’s emotional states, with estrogen and progesterone having predominant roles. However, it remains unclear whether the phases of the menstrual cycle also affect women’s motivational behaviors. In this study, the main aim was to investigate how the menstrual cycle influences approach–avoidance behavior under conditions of conscious versus unconscious processing of emotions. Briefly, after recruitment by advertisement and screening with a menstrual cycle survey questionnaire, 27 naturally cycling, healthy women participated in an improved “manikin task” and were presented both positive and negative emotional stimuli during early follicular, late follicular, and mid-luteal phases. Estrogen and progesterone levels were measured. Women in the late follicular phase exhibited the shortest response times for approaching positive stimuli, while women in the mid-luteal phase exhibited the shortest response times for avoiding negative stimuli. Estrogen and progesterone levels significantly correlated with the speed of the approach–avoidance responses observed for the women, indicating the important role that sex hormones have in mediating emotionally motivated behavior. Overall, these findings suggest that the menstrual cycle has strong and specific influences on women’s approach–avoidance behaviors that are in part mediated by estrogen and progesterone. By identifying characteristics of these behaviors in the late follicular and mid-luteal phases, greater insight can be provided to women regarding the physiological influences of the menstrual cycle on their personal growth and security.

Influence of Menstrual Cycle on Leukocyte Response Following Exercise-Induced Muscle Damage.

We investigated the influence of the menstrual cycle (MC) on leukocyte response after exercise-induced muscle damage (EIMD). During the early follicular (E-FP, n = 12) or mid-luteal phase (M-LP, n = 12), 24 untrained females with eumenorrhea performed 60 eccentric exercises using nondominant arms. Blood samples were collected at pre- and 4, 48, and 96 h postexercise to analyze estradiol and progesterone concentrations, leukocyte count and fractionation, and creatine kinase (CK) activity. We also assessed the maximal voluntary isometric contraction torque of elbow flexion, range of motion in the elbow joint, upper-arm circumference, and muscle soreness as indirect muscle damage markers at pre-; immediately post-; and 4, 48, and 96 h postexercise. The percent change in neutrophil counts from pre- to 4 h postexercise was lower in M-LP than in E-FP (E-FP, 30.7% [15.9–65.7%] vs. M-LP, 10.3% [−2.3–30.0%]; median [interquartile range: 25–75%]; p = 0.068). Progesterone concentration at pre-exercise was significantly negatively correlated with the percent change in neutrophil counts from pre- to 4 h postexercise in M-LP (r = −0.650, p = 0.022). MC did not affect CK activity or other muscle damage markers. Thus, progesterone concentration rather than MC may be related to neutrophil response following EIMD.

The Cycling Brain in the Workplace: Does Workload Modulate the Menstrual Cycle Effect on Cognition?

Recent decades have witnessed increased research efforts to clarify how the menstrual cycle influence females’ cognitive and emotional functions. Despite noticeable progress, the research field faces the challenges of inconsistency and low generalizability of research findings. Females of reproductive ages are a heterogeneous population. Generalizing the results of female undergraduates to women in the workplace might be problematic. Furthermore, the critical cognitive processes for daily life and work deserve additional research efforts for improved ecological validity. Thus, this study investigates cognitive performance across the menstrual cycle using a sample of young nurses with similar duties. We developed a mini-computerized cognitive battery to assess four mental skills critical for nursing work: cognitive flexibility, divided attention, response inhibition, and working memory. Participants completed the cognitive battery at menses, late-follicular, and mid-luteal phases. In addition, they were classified into low- and high workload groups according to their subjective workload ratings. Our results demonstrate a general mid-luteal cognitive advantage. Besides, this study reveals preliminary evidence that workload modulates the menstrual cycle effect on cognition. Only females of low workload manifest the mid-luteal cognitive advantage on divided attention and response inhibition, implying that a suitable workload threshold might be necessary for regular neuro-steroid interactions. Thus, this study advocates the significance of research focusing on the cycling brain under workloads.