Understanding the effects of the menstrual cycle on training and performance in elite athletes: A preliminary study

Subjective and Objective Monitoring Markers: Are They Related to Game Performance Indicators in Elite Female Volleyball Players?

PURPOSE

This cohort study aimed to investigate the relationship between subjective (wellness and internal training load [ITL]) and objective (neuromuscular fatigue) monitoring markers and performance aspects (reception quality [RQ] and attack efficiency [AE]) in professional female volleyball players.

METHODS

The study was conducted over an 8-week period during the final mesocycle of the competitive phase. A total of 24 training sessions and 10 matches were included in the analysis. Subjective measures of wellness and ITL were assessed, and neuromuscular fatigue was evaluated using countermovement-jump (CMJ) height. RQ and AE were determined based on game statistics.

RESULTS

The study found a positive relationship between wellness and RQ, particularly affecting outside hitters and liberos. ITL showed a positive association with AE, primarily impacting outside hitters, opposite hitters, and middle blockers. Additionally, ITL demonstrated a negative correlation with RQ, mainly affecting outside hitters and liberos. CMJ performance was associated with AE, where a decrease in CMJ height was linked to reduced AE.

CONCLUSIONS

The findings highlight the importance of considering players' wellness scores in training and match strategies for different positions. Careful management of training loads, considering both physical and technical demands, is crucial for optimizing performance outcomes. Monitoring neuromuscular fatigue, as indicated by CMJ performance, is particularly relevant for outside hitters, opposite hitters, and middle blockers involved in attack actions. Coaches, trainers, and sports practitioners can use these insights to develop position-specific training protocols and implement effective strategies for maintaining or improving performance metrics under various stressors.

Using Hormone Data and Age to Pinpoint Cycle Day within the Menstrual Cycle

Background and Objectives: Menstrual cycle tracking is essential for reproductive health and overall well-being. However, there is still an over-reliance on estimations that standard cycles are 28 days long, divided evenly between the follicular and luteal phases. Due to the variability of cycle length and cycle phase lengths, common methods of identifying where an individual is in their cycle are often inaccurate. This study used daily hormone monitoring obtained through a remote hormone-monitoring platform to evaluate hormone levels across a menstrual cycle to identify nuances in the follicular and luteal phases in individuals of different age groups. Materials and Methods: This study used a remote fertility testing system that quantitatively tracks luteinizing hormone (LH) and pregnanediol-3-glucuronide (PdG) through urine tests read by an AI-powered smartphone app. The study analyzed cycle data from 1233 users with a total of 4123 evaluated cycles. Daily levels for LH and PdG were monitored across multiple cycles. Results: This study determined that calculated cycle lengths tended to be shorter than user-reported cycle lengths. Significant differences were observed in cycle phase lengths between age groups, indicating that follicular phase length declines with age while luteal phase length increases. Finally, the study found that if an individual's age, first cycle day, and current hormone levels are known, population-level hormone data can be used to pinpoint which cycle phase and cycle day they are in with 95% confidence. Conclusions: At-home hormone monitoring technologies can allow patients and clinicians to track their cycles with greater precision than when relying on textbook estimations. The study's findings have implications for fertility planning, clinical management, and general health monitoring. Prior to this study, no standard existed for pinpointing where a person was in their cycle through only one measure of LH and PdG. These findings have the potential to fill significant gaps within reproductive healthcare and beyond.

Experiences of menstruation in high income countries: A systematic review, qualitative evidence synthesis and comparison to low- and middle-income countries

BACKGROUND

There is growing recognition of the importance of menstruation in achieving health, education, and gender equality for all. New policies in high income countries (HICs) have responded to anecdotal evidence that many struggle to meet their menstrual health needs. Qualitative research has explored lived experiences of menstruating in HICs and can contribute to designing intervention approaches. To inform the growing policy attention to support people who menstruate, here we review and synthesise the existing research.

METHODS AND FINDINGS

Primary, qualitative studies capturing experiences of menstruation in HICs were eligible for inclusion. Systematic database and hand searching identified 11485 records. Following screening and quality appraisal using the EPPI-Centre checklist, 104 studies (120 publications) detailing the menstrual experiences of over 3800 individuals across sixteen countries were included. We used the integrated model of menstrual experiences developed from studies in low- and middle-income countries (LMICs) as a starting framework and deductively and inductively identified antecedents contributing to menstrual experiences; menstrual experiences themselves and impacts of menstrual experiences. Included studies described consistent themes and relationships that fit well with the LMIC integrated model, with modifications to themes and model pathways identified through our analysis. The socio-cultural context heavily shaped menstrual experiences, manifesting in strict behavioural expectations to conceal menstruation and limiting the provision of menstrual materials. Resource limitations contributed to negative experiences, where dissatisfaction with menstrual practices and management environments were expressed along with feelings of disgust if participants felt they failed to manage their menstruation in a discrete, hygienic way. Physical menstrual factors such as pain were commonly associated with negative experiences, with mixed experiences of healthcare reported. Across studies participants described negative impacts of their menstrual experience including increased mental burden and detrimental impacts on participation and personal relationships. Positive experiences were more rarely reported, although relationships between cis-women were sometimes strengthened by shared experiences of menstrual bleeding. Included studies reflected a broad range of disciplines and epistemologies. Many aimed to understand the constructed meanings of menstruation, but few were explicitly designed to inform policy or practice. Few studies focused on socioeconomically disadvantaged groups relevant to new policy efforts.

CONCLUSIONS

We developed an integrated model of menstrual experience in HICs which can be used to inform research, policy and practice decisions by emphasising the pathways through which positive and negative menstrual experiences manifest.

REVIEW PROTOCOL REGISTRATION

The review protocol registration is PROSPERO: CRD42019157618.

The Effects of Menstrual Cycle Phase on Elite Athlete Performance: A Critical and Systematic Review

Background: In elite athletes, training individualization is widely recommended to optimize competitive performance. Previous studies have evidenced the impact of hormonal fluctuations on different performance parameters among female athletes. While consideration of menstrual cycle (MC) phases as a parameter in training individualization strategies is necessary, systematic evidence identifying such impacts in elite athletes should be evaluated. Objective: Systematically review publications that have investigated the link between MC phases and performance in elite female athletes. The overarching aim is to identify whether a consensus across studies exists enabling evidence-based recommendations for training individualization depending on menstrual cycle phases. Methods: This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Three major scientific publication databases were searched from inception until November 3, 2020. Studies included focused on the influence of physiological or psychological parameters throughout at least one phase of the menstrual cycle of elite athletes. Results: A total of 780 search results were yielded and 26 references from a past bibliography were added manually. About 662 papers were reviewed of which 218 studies were assessed for eligibility. Of these, only seven (1%) precisely investigated the influence of a performance or physical parameter during at least one menstrual cycle phase. These seven studies included a total of 314 elite female participants (20.58 ± 1.91 years). Three used interviews, questionnaires or prospective analyses of reports. Four conducted several performance tests or included physical measures although only two performed tests during training or before/during competition. Among the seven studies, five performed hormonal testing through sampling of blood, saliva, or urine. The remaining relied on athletes' menstruation diaries. The current evidence suggests a variable association between menstrual cycle and a few performance-related outcomes, such as endurance or power resistance, ligament stiffness, decision making skills, psychology, or competitiveness. Conclusion: Different sports performance-related parameters are affected during the menstrual cycle among elite athletes, but the parameters themselves and the magnitude and the direction of the effects are inconclusive. Additional longitudinal and prospective studies to systematically monitor on-field performance parameters are urgently required in order to enable recommendations and training individualization in female elite athletes.

Asthma, atopy, and exercise: Sex differences in exercise-induced bronchoconstriction

Asthma is a chronic inflammatory lung disease affecting approximately 7.7% of the US population. Sex differences in the prevalence, incidence, and severity of asthma have been widely described throughout the lifespan, showing higher rates in boys than girls before puberty, but a reversed pattern in adults. Asthma is often associated with atopy, i.e. the tendency to develop allergic diseases, and can be worsened by environmental stimuli and/or exercise. While not exclusive to patients with asthma, exercise-induced bronchoconstriction (EIB) is a common complication of athletes and individuals who exercise regularly. Currently, there is limited research on sex differences in EIB and its relationship with atopy and asthma in men and women. In this minireview, we summarize the available literature on this topic. Overall, the collective knowledge supports the notion that physiological changes triggered during exercise affect males and females differently, suggesting an interaction among sex, exercise, sex hormones, and atopic status in the course of EIB pathophysiology. Understanding these differences is important to provide personalized management plans to men and women who exercise regularly and suffer from underlying asthma and/or atopy.

The Impact of Menstrual Cycle Phase on Athletes' Performance: A Narrative Review

The effect of the menstrual cycle on physical performance is being increasingly recognised as a key consideration for women's sport and a critical field for further research. This narrative review explores the findings of studies investigating the effects of menstrual cycle phase on perceived and objectively measured performance in an athletic population. Studies examining perceived performance consistently report that female athletes identify their performance to be relatively worse during the early follicular and late luteal phases. Studies examining objective performance (using anaerobic, aerobic or strength-related tests) do not report clear, consistent effects of the impact of menstrual cycle phase on physical performance. Overall sport performance can be influenced by both perceived and physical factors. Hence, to optimise performance and management of eumenorrheic female athletes, there is a need for further research to quantify the impact of menstrual cycle phase on perceived and physical performance outcomes and to identify factors affecting variability in objective performance outcomes between studies.