Women’s health in sport: The prevalence and impact of heavy menstrual bleeding and iron deficiency

Menstruation is the leading cause of iron deficiency anaemia in pre-menopausal women. When combined with regular exercise, iron deficiency (ID) risk in menstruating women is increased. This may be exacerbated in those with heavy menstrual bleeding (HMB), which despite no validated diagnosis, is thought common in the general population but is under-investigated in exercisers. Accordingly, the potential relationship between menstruation, ID and performance remains unknown. The aims of this research were to: a) identify HMB prevalence (utilising a diagnostic series) and association with fatigue and perceived disruption to exercise training/performance in exercising women; b) evaluate the impact and existing diagnosis of ID. A ‘Female Health Questionnaire’ was developed to identify HMB amongst other factors in an exercising population (n=789), elite athletes (n=90) and London Marathon runners (n=1073). The relationships between iron status, HMB and fatigue or the perception that the menstrual cycle disrupts exercise training/performance was then investigated in exercising women (n=271). Finally, a clinical trial assessed the impact of intravenous iron repletion (single dose of 20 mg·kg-1) on exercise and aerobic capacity, haematological markers, fatigue and mood disturbance in non-elite, iron deficient (serum ferritin ≤30µg·L-1), exercising women (n=32). HMB was identified to be common (37% elite athletes, 36% marathon runners), and associated with perceived disruption to exercise training/performance and fatigue, but these relationships were independent of iron status. Iron repletion improved exercise and aerobic capacity, but only in those more severely iron deficient (serum ferritin <15µg·L-1), with wide individual variation, unrelated to baseline serum ferritin. In conclusion, HMB is a risk factor for ID, physiological and psychological function decrements in exercising women. Intravenous iron repletion effectively restores iron status and improves functional exercise capacity when true ID exists. Serum ferritin as a biomarker for ID and its associated normative data should be re-evaluated to avoid false positive ID diagnosis

Early sport specialization and intensive training in adolescent female athletes: Risks and recommendations

Early sport specialization is often characterized by intensive training and is becoming increasingly common. Adolescent female athletes, who train excessively and adopt poor diets, are at risk of the female athlete triad, overuse injury, mental health issues, and overtraining. The occurrence of one or more of these issues can lead to early retirement from sport and may have serious long-term health consequences. Practitioners working with young females are recommended to adopt a holistic approach to the development of their athletes, including participation in a diverse range of sports, monitoring health status, and ensuring caloric intake meets the demands of the athlete's lifestyle

Injury incidence, severity and type across the menstrual cycle in female footballers:A prospective three season cohort study

AbstractPurpose The aim of the study was to assess the influence of menstrual cycle phase on injury incidence, severity and type in elite female professional footballers over three seasons.Methods Time-loss injuries and menstrual cycle data were prospectively recorded for 26 elite female football players across three seasons. The menstrual cycle was categorised into four phases using a standardised model: menstruation (phase 1; P1), remainder of follicular phase (phase 2; P2), early luteal (phase 3; P3), and pre-menstrual phase (phase 4; P4). Injury incidence rates (IRR) and ratios (IIRR) were calculated for overall injuries, injury severity, type, contact vs non-contact and game/training.Results 593 cycles across 13,390 days were tracked during the study and 74 injuries from 26 players were eligible for analysis. When comparing IRR between phases (reference: P1), overall injury rates were highest in P4 (IIRR: 2.30 [95% CI: 0.99-5.34; p = 0.05]). When examining rates by injury severity and type, IRR were also highest in P4 for ≤7 days’ time-loss (4.40 [0.93-20.76; p = 0.06]), muscle-specific (6.07 [1.34-27.43; p = 0.02]) and non-contact (3.05 [1.10-8.50; p = 0.03]) injuries. Muscle-specific (IIRR P3:P1: 5.07 [1.16-22.07; p = 0.03]) and ≤ 7 days’ time-loss (4.47 [1.01-19.68; p = 0.05]) injury risk was also significantly higher in P3. Muscle injuries were the most prevalent sub-type (n = 41). No anterior cruciate ligament injuries were recorded across the monitoring period.Conclusions Injury risk was significantly elevated during the luteal phase of the menstrual cycle (P3 and P4) among elite female professional footballers. Further research is urgently needed to better understand the influence of the menstrual cycle on injury risk and to develop interventions to mitigate risk

Variations in Strength-Related Measures During the Menstrual Cycle in Eumenorrheic Women

Objectives: To systematically review the current body of research that has investigated changes in strength-related variables during different phases of the menstrual cycle in eumenorrheic women. Design: Systematic review and meta-analysis. Method: A literature search was conducted in Pubmed, SPORTDiscus and Web of Science using search terms related to the menstrual cycle and strength-related measures. Two reviewers reached consensus that 21 studies met the criteria for inclusion. Methodological rigor was assessed using the Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Random effects meta-analyses were used to compare the early-follicular, ovulatory and mid-luteal phases for maximal voluntary contraction, isokinetic peak torque, and explosive strength. Results: The assessment of study quality showed that a high level of bias exists in specific areas of study design. Non-significant and small or trivial effect sizes (p≥0.26, Hedges g ≤0.35) were identified for all strength-related variables in each comparison between phases. 95% confidence intervals for each comparison suggested the uncertainty associated with each estimate extends to a small effect on strength performance with unclear direction (-0.42≤ g ≤0.48). The heterogeneity for each comparison was also small (p≥0.83, I2=0%). Conclusions: Strength status appears to be minimally altered (g ≤0.35) by the fluctuations in ovarian sex hormones that occur during the menstrual cycle. This finding should be interpreted with caution due to the methodological shortcomings identified by the quality assessment

Teachers' perceptions and experiences of menstrual cycle education and support in UK schools

The purpose of this study was 2-fold, to (1) explore current education provision in UK schools including barriers to menstrual cycle education and (2) assess the perceived support teachers received to deliver menstrual cycle education. Seven hundred eighty-nine teachers (91% female) from all stages of school education in England (48%), Scotland (24%), Wales (22%) and Northern Ireland (6%) completed an online survey. The survey captured information on menstrual education in schools, teacher's knowledge and confidence of the menstrual cycle, support provided to teachers, provision of menstrual products in school and perceived impact of the menstrual cycle on young people in school. Four hundred ninety-eight teachers reported lessons were provided on the menstrual cycle (63%), predominantly delivered within personal, social, health and economic or science subjects, with over half of the lessons focusing on the biology (56%) or provision of menstrual products (40%) rather than lived experiences (14%). Teachers perceived the menstrual cycle affected participation in PE (88%), pupil confidence (88%), school attendance (82%) and attitude and behavior (82%). Overall, 80% of teachers felt receiving training would be beneficial to improve menstrual education. The results highlight education is scientifically focused, with less education on management of symptoms or lived experiences. Teachers also perceive the menstrual cycle to influence multiple aspects of school attendance and personal performance. There is a need to address menstrual education provided in schools across the UK to help empower girls to manage their menstrual cycle, preventing a negative impact on health and school performance

Menstrual Cycle: The Importance of Both the Phases and the Transitions Between Phases on Training and Performance

The authors present opinions based on their applied experiences of working with female athletes in combination with the existing evidence-based literature. Most of the existing menstrual cycle research focuses on a few steady-state time points within the pre-defined menstrual cycle phases, yet this disregards the day-to-day hormonal changes that women have to accommodate to perform optimally and consistently. The traditional research models are inadequate for studying symptoms and symptom management, and ultimately for supporting athletes to perform well throughout the entirety of their cycle. As such, the monitoring of the day-to-day variation, particularly during the transitions between menstrual cycle phases appears to be an important “overlooked” consideration. This is particularly pertinent considering the known intra-individual and inter-individual variation in menstrual cycle characteristics. Anecdotal and research evidence supports the idea that athletes can use non-pharmacological solutions to mitigate negative menstrual cycle symptoms and do not need to “grit their teeth and roll with it”. However, further research (including case studies) is needed in this important research area. Such knowledge should be and needs to be widespread amongst practitioners and athletes as they should not have to figure this out alone. As such, researchers and practitioners need to put more work into understanding symptom aetiology, symptom clusters and their relationship with hormonal changes, menstrual cycle phases and transitions, with potential for a profound impact on individual athlete health and well-being. In so doing, those working with female athletes need to continue building on the recent progress made in educating athletes and practitioners; for example, normalising the discussion of and about the menstrual cycle and all of its implications

Modelling menstrual cycle length in athletes using state-space models

The ability to predict an individual’s menstrual cycle length to a high degree of precision could help female athletes to track their period and tailor their training and nutrition correspondingly. Such individualisation is possible and necessary, given the known inter‐individual variation in cycle length. To achieve this, a hybrid predictive model was built using data on 16,524 cycles collected from a sample of 2125 women (mean age 34.38 years, range 18.00–47.10, number of menstrual cycles ranging from 4 to 53). A mixed‐effect state‐space model was fitted to capture the within‐subject temporal correlation, incorporating a Bayesian approach for process forecasting to predict the duration (in days) of the next menstrual cycle. The modelling procedure was split into three steps (1) a time trend component using a random walk with an overdispersion parameter, (2) an autocorrelation component using an autoregressive moving‐average model, and (3) a linear predictor to account for covariates (e.g. injury, stomach cramps, training intensity). The inclusion of an overdispersion parameter suggested that 26.36% [23.68%, 29.17%] of cycles in the sample were overdispersed. The random walk standard deviation for a non‐overdispersed cycle is 27.41 ± 1.05 [1.00, 1.09] days while under an overdispersed cycle, the menstrual cycle variance increase in 4.78 [4.57, 5.00] days. To assess the performance and prediction accuracy of the model, each woman’s last observation was used as test data. The root mean square error (RMSE), concordance correlation coefficient and Pearson correlation coefficient (r) between the observed and predicted values were calculated. The model had an RMSE of 1.6412 days, a precision of 0.7361 and overall accuracy of 0.9871. In conclusion, the hybrid model presented here is a helpful approach for predicting menstrual cycle length, which in turn can be used to support female athlete wellness

Menopausal symptoms, exercise practices, and advice received in active women: a multi-country survey of strava app users

The study aimed to identify the prevalence of symptoms, changes in exercise levels, and exercise advice received during the menopausal transition in a large multi-country sample. Using total population sampling, 2.5 percent of female Strava app users (n = 970) from 7 countries completed an online survey between 14 February 2019 and 11 March 2019. The survey discussed menopause status (perimenopausal or postmenopausal), menopausal symptoms, changes to exercise behaviors, and advice received concerning exercise during menopause. Frequencies, chi-square statistics, and linear regressions were used to analyze data. The most commonly reported menopausal symptoms were sexual (18-83 percent) and cognitive/psychological (77-78 percent). 41 percent of women reported no change in exercise behavior since menopause began (46 percent increased and 11 percent decreased behaviors). The majority (88 percent) of women did not receive advice regarding exercise during menopause. Women who received advice were more likely to report an increase in their exercise than those not receiving advice (60 percent vs 46 percent; X2 (df 2, n = 927) = 7.1, p = .03). Exercise behaviors increased the longer it had been since the menopausal onset (X2 (df 8, n = 937) = 77.42, p < .001). The results suggested high menopausal symptom prevalence in active women and a general lack of exercise advice. More women reported higher symptom prevalence and an increase in exercise participation, the longer it had been since menopause onset. Future research should determine whether these increased exercise behaviors are being used as a coping mechanism

The development and initial validation of the Health and Reproductive Survey (HeRS).

Due to the diversity in profiles associated with the female reproductive cycle and their potential physiological and psychological effects, monitoring the reproductive status of exercising females is important from a practical and research perspective. Moreover, as physical activity can influence menstrual function, the effects of physical activity energy expenditure on reproductive function should also be considered. The aim of this study was to develop and establish initial face and content validity of the Health and Reproductive Survey (HeRS) for physically active females, which is a retrospective assessment of menstrual function from menarche (first menstruation) to menopause (cessation of menstruation). Face validity was evaluated qualitatively, and the initial content validity was established through a principal component analysis. The face validity process was completed by 26 females aged 19-67 years and the content validity was established through a survey sent to a convenience sample of 392 females, of which 230 females (57.9% and aged 18-49 years) completed the survey. The revisions made following the face validation improved the understanding, flow, and coherence of the survey. The principal component analysis indicated that, at a minimum, the survey measures these constructs: menstrual cessation and associated moderators, athletic participation and performance levels (as associated with menstruation change and the menstrual cycle), age and menstrual cessation, hormonal contraception ("birth control"), and menarche and associated moderators. The Health and Reproductive Survey (HeRS) is a partially validated tool that can be used by researchers to characterize the menstrual status of physically active females relative to their physical activity status