Menstrual cycle monitoring in applied sport settings: A scoping review

Abstract

Objectives

The aim of this review was to summarise the existing literature concerning the implementation of menstrual cycle tracking in applied sport settings.

Methods

For this scoping review, database searches were conducted in ProQuest, PubMed, Scopus, SportDISCUS, and Web of Science. Screening was performed by two independent reviewers to identify academic publications that related to the concept of menstrual cycle tracking in applied sport settings.

Results

Twenty-six articles published between 2001 and 2024 fulfilled the inclusion criteria. These were most commonly original research articles (n = 19) and published in the last two years (n = 20). One research protocol paper and six opinion articles published in academic journals were also included. Twelve of the 26 publications recommend implementing tracking in sport settings; many publications also encourage providing education (n = 13) and facilitating more open communication (n = 10) on menstrual-related topics. Where tracking was conducted, this was done using calendar-based methods alone (n = 5) or in conjunction with urinary (n = 3), capillary blood (n = 2) and venous blood (n = 1) hormone measures, and ovulation test kits (n = 1).

Conclusions

Menstrual cycle tracking may be a useful tool for promoting self-awareness, identifying menstrual dysfunction, and managing menstrual symptoms. However, in practice there are potential risks, such as loss of privacy or misuse of data. There is also a need for ecologically valid tracking tools that can identify subtle menstrual disturbances, to make tracking more beneficial and efficient.

Introduction

Athlete monitoring is a prominent component of athlete support and preparation strategies in high performance settings. These monitoring processes can be undertaken with a variety of tools and consider a multitude of variables, including internal (i.e., rating of perceived exertion, heart rate response) and external load (i.e., power output, movement demands). ¹ With the growing professionalisation of sport for female athletes there is increasing interest in monitoring additional variables pertaining to the menstrual cycle. Menstrual cycle tracking is a practice where an individual records when they experience menstruation, to indicate the start and end of consecutive menstrual cycles. Tracking may also involve recording additional variables, such as heaviness of menstrual blood flow and symptoms, and female sex hormone concentrations, or estimated day of ovulation to capture a more detailed picture of menstrual health. ²

A functional menstrual cycle, also referred to as eumenorrhea, is characterised by an individual experiencing menstruation on a regular basis (i.e., every 21–35 days), and demonstrating ovulation and an expected hormonal profile throughout. ³ Menstrual function can be described on a continuum (Figure 1), where an appropriately functioning menstrual cycle would first demonstrate subtle disturbances (i.e., anovulation or luteal phase deficiency) before progressing to more severe forms of dysfunction like oligomenorrhea, then amenorrhea. ⁴ Some research indicates longitudinal tracking to capture menstrual cycle length and ovulation could enable identification of conditions along this continuum ⁵ ; for example, flagging menstrual cycles that last longer 35 days or where no positive ovulation test results are recorded. As such, tracking menstrual function may be useful in sport settings due its relation to relative energy deficiency in sport (REDs) risk, bone health, and fertility. ⁶ Tracking may also help to identify menstrual dysfunction related to abnormal bleeding or symptoms (i.e., menorrhagia, premenstrual syndrome/dysphoric disorder). ⁷

Figure 1.

Continuum of menstrual function, adapted from Mallinson and De Souza. ⁴ .

Menstrual cycle tracking is also considered as a potential tool to optimise performance by modifying training, recovery, or nutrition programs based on menstrual cycle phase. Multiple systematic reviews, investigating the effect of menstrual cycle phase on performance, ⁸ exercise induced muscle damage, ⁹ athletes’ perceptual responses, ¹⁰ thermoregulatory responses to exercise in heat, ¹¹ and responses and adaptations to resistance training ¹² have been published within the last five years, demonstrating the recent surge in interest in this topic. The main findings from these reviews are that any effect from cycle phase is small and many studies were limited by small sample sizes. Based on these review findings, it was recommended approaches to menstrual cycle tracking and any changes to programming are both individualised to the athlete.^8,10

There is some uptake of these suggestions, with athletes choosing to track their menstrual cycles personally, or tracking being undertaken as either mandatory or optional additions to their sporting organisations’ athlete monitoring processes. ¹³ While there is now guidance for menstrual cycle tracking within research design, ³ there is limited guidance on how to track menstrual cycles in applied sport settings to support the decision-making process (i.e., the initial decision to track cycles and subsequent decisions regarding what to track, how to use data, data privacy, etc). Tracking may also be implemented without end-users having sufficient understanding of menstrual cycle physiology, with current evidence showing many athletes and practitioners have limited knowledge pertaining to menstrual health.^14,15 This understanding of menstrual cycle physiology is important as the purpose of tracking may be influenced by the users’ characteristics. For example, menstrual cycle tracking is not a useful practice for identifying menstrual dysfunction such as anovulation or amenorrhea in hormonal contraceptive users, who make up a considerable proportion (approximately 40%) of the female athlete population. ¹⁶

It is crucial to provide specific guidance for practitioners because various constraints and considerations – such as the purpose of tracking, financial and time costs, athlete availability and scheduling, menstrual stigma, and practitioner expertise – mean that research-focused menstrual cycle tracking likely differs from tracking occurring in practice. Therefore, the aim of this scoping review is to summarise the existing literature exploring the concept of implementing of menstrual cycle tracking in the context of applied sport settings. For practitioners in applied settings, this review will provide a summary of available evidence to inform decision making around their menstrual cycle tracking practices. For researchers, this review will highlight the scope for future research to address gaps in the literature.

Methods

This scoping review followed Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines and was prospectively registered on Open Science Framework (https://doi.org/10.17605/OSF.IO/TW2JX).

Search strategy

An electronic literature search (Table 1) for terms related to menstrual cycle tracking and sport was conducted in the following databases: ProQuest, PubMed, Scopus, SportDiscus, and Web of Science on the 9^th January 2024 and repeated on the 26^th August 2024 to capture recent publication. The search results were exported into EndNote 21 ¹⁷ where duplicates were removed before being uploaded to review management software Covidence ¹⁸ for screening. Additional studies were identified via forward and backward citation searches of the articles included following full-text screening using citationchaser. ¹⁹

Table 1.

Full search strategy.

ProQuest	((“menstrual cycle” OR “menstrual cycles”) AND (“monitor” OR “monitoring” OR “track” OR “tracking”)) AND (“sport” OR “sport*” OR “athlete” OR “coach” OR “athletes” OR “coaches”)
PubMed	(“menstrual cycle"[All Fields] OR “menstrual cycles"[All Fields]) AND (“monitor"[All Fields] OR “monitoring"[All Fields] OR “track"[All Fields] OR “tracking"[All Fields]) AND (“sport"[All Fields] OR “sport*"[All Fields] OR “athlete"[All Fields] OR “coach"[All Fields] OR “athletes"[All Fields] OR “coaches"[All Fields])
Scopus	ALL (((“menstrual cycle” OR “menstrual cycles”) AND (“monitor” OR “monitoring” OR “track” OR “tracking”)) AND (“sport” OR “sport*” OR “athlete” OR “coach” OR “athletes” OR “coaches”))
SportDiscus	((“menstrual cycle” OR “menstrual cycles”) AND (“monitor” OR “monitoring” OR “track” OR “tracking”)) AND (“sport” OR “sport*” OR “athlete” OR “coach” OR “athletes” OR “coaches”)
Web of Science	((“menstrual cycle” OR “menstrual cycles”) AND (“monitor” OR “monitoring” OR “track” OR “tracking”)) AND (“sport” OR “sport*” OR “athlete” OR “coach” OR “athletes” OR “coaches”) (All Fields)

Source selection

Any academic publication that was peer-reviewed, published in English, and relevant to the concept of implementing menstrual cycle tracking in the context of sport settings was eligible for inclusion. Further, the aim of the article either needed to relate to the implementation of menstrual cycle tracking, or tracking emerged as an outcome or focus of the article. Many original research articles examining the effect of menstrual cycle phases on outcome variables recommend implementing menstrual cycle tracking. However, these articles were excluded because the implementation of tracking in applied settings was not the main purpose of the study. For the purpose of this review, menstrual cycle tracking refers to the ongoing recording of when menstruation occurs, and potentially other outcomes (e.g., ovulation, heaviness of bleeding, symptoms, hormone measures). Any articles that focused on menstrual health screening (i.e., a historical questionnaire) rather than prospective tracking were not included in this review as the periodic versus continuous nature of screening and tracking, respectively, mean there are different considerations to be made in the implementation of these practices in applied settings. Articles were considered relevant to an applied sport context if the participants were referred to as ‘athletes’ or described as training to compete or perform, were part of the athlete support network (e.g., with practitioners, coaches, or parents of athletes), or the article discussed menstrual cycle tracking as an athlete monitoring tool (i.e., used to support health, wellbeing, and/or performance). Articles were excluded if the participants were from general or clinical populations, or if the discussion of menstrual cycle tracking took place within the context of conducting research (i.e., guidance for cycle tracking in research protocols).

Two reviewers (MC, AC) completed independent title and abstract screening, with conflicts resolved by a third reviewer (KP). The full-texts of potentially relevant articles, identified in this initial stage of screening, were sourced from open-access sources, the University library, and where required, contacting the corresponding author. Full-text screening was completed by two independent reviewers (MC, KP) and conflicts were resolved via a consensus meeting with a third reviewer (AC).

Data extraction and analysis

A descriptive-analytical approach was taken to charting the data, meaning we collected standard information from each study to understand the context in which the articles were published to help us make sense of their findings. ²⁰ The following information was extracted from all included articles: year of publication, country, type of publication, details regarding menstrual cycle tracking methods or processes, and the authors’ conclusions or practical takeaways regarding menstrual cycle tracking. Additional information such as study design, participant characteristics, and study findings were also extracted from the included original research articles. One reviewer (MC) populated a data extraction form on Microsoft Excel, ²¹ which was cross-checked by a second reviewer (VK). A narrative synthesis of the extracted results was then conducted, in which the results were considered together and findings summarised in text.

Results

The database searches retrieved a total of 10,757 articles. Following the removal of duplicates, and title and abstract screening, the full-texts of 87 publications were sourced and their eligibility assessed (Figure 2). Overall, 26 publications were included in this review; 19 original research articles, one original research protocol, and six opinion articles published in academic journals. The earliest original research article was a 2001 non-randomised control trial on the usefulness and feasibility of monitoring athletes’ ovarian hormone responses to training. ⁵ However, the majority of included publications were published in in the last two years (n = 20). The included publications most frequently originated from the United Kingdom (n = 10), followed by Australia (n = 4).

Figure 2.

Flow chart of literature search results.

Within the included original research articles (Table 2), most studies used a quantitative methodology (n = 13) and one article was a protocol for a study that is currently underway. ²² Mixed methods (n = 3) and qualitative (n = 3) approaches were also utilised. These studies predominantly focused solely on athlete participants (n = 14), while some looked at both athlete and their support network (e.g., coaches, support staff, and parents) (n = 3) or were only with sports practitioners (e.g., coaches) (n = 2). Many of these studies included participants involved in a variety of sports (n = 7) or specifically in soccer (n = 7). In the articles where menstrual cycle tracking was conducted (n = 11), five studies used calendar-based methods only.^23–27 In addition to calendar-based tracking, the remaining articles included urinary hormone measures (n = 3),^5,22,28 hormone measures via capillary (n = 2)^29,30 and venous blood (n = 1)^{, 31} and ovulation test kits (n = 1). ³¹

Table 2.

Original research articles that fulfilled inclusion criteria.

Author Year	Country	Study Design	Aim	Participants	Menstrual Cycle Tracking protocol	Study Findings	Conclusion
Barlow 2023	UK	Prospective cohort	Investigate the influence of MC phase on injury incidence, severity, and type.	Regularly menstruating professional soccer athletes (n = 26); Minimum Tier 3; Over the age of 18 (avg. 24.1 ± 4.6 years).	Calendar-based tracking via sport-specific MC tracking mobile application to record days of menstruation and flow intensity. MC phase identified using algorithm in application.	Overall injuries rates were lowest in phase 1 (i.e., menstruation) and highest in phase 4 (i.e., pre-menstrual phase). Overall injury rates were lowest in phase 1 (i.e., menstruation) and highest in phase 3 and 4 (i.e., luteal phase).	Crucial MC tracking is implemented alongside injury surveillance. Collection of hormone measures impractical in high performance environment due to invasiveness and cost.
Bouchard 2023	CAN	Prospective cohort protocol	Validate an at-home urinary hormone monitor against serum hormone measures and endovaginal ultrasound.	Regularly menstruating females (n = 60), and females diagnosed with PCOS and oligomenorrheic athletes (n = 60); aged 18–35.	Calendar-based tracking via mobile application (to record daily menstrual flow intensity, and basal body temperature). Urinary FSH, E13G, LH, and PDG measures via Mira monitor. Serum AMH, FSH, estrogen, LH, and progesterone. Serial endovaginal follicular tracking ultrasounds.	Not applicable (protocol only).	If validated, at-home hormone measures offer a cheaper and less burdensome method of identifying subtle menstrual disturbances. This may be useful for planning training or decision-making regarding fertility, given hypofertility is associated with oligomenorrhea, particularly in athletes.
Brown 2021	UK	Qualitative descriptive study	Examine elite athletes’ experiences of their MC, including its influence on training/competition and the openness of communication related to MCs.	Female Weightlifting, Athletics, Climbing, Gymnastics, and Judo athletes (n = 17); Minimum Tier 4; Aged 18–34; Current HC users (n = 5).	Not applicable.	9/17 athletes reported tracking their MC, which was seen to be useful in improving self-awareness of symptoms, and their effect on training or competition, and identifying effective management strategies.	MC tracking can be advised to some athletes to improve self-awareness and develop management strategies. Some caution should be made due to possibility of athletes becoming increasingly anxious as result of being more aware of their cycle via tracking.
Carmichael 2024	AUS	Mixed-methods participatory approach	Identify considerations for implementing MC tracking in sport.	Female athletes over the age of 16 (n = 12); Coaches and support staff working with female athletes (n = 14; including females = 8, males = 6).	Not applicable.	The overarching considerations for tracking include: 1) Ethics, 2) Tracking Tools and Methods, 3) Performance and Health, 4) Education, 5) Interpretation and Framing and 6) Communication. The most important and feasible consideration to the participants was Ethics, and the least important and feasible was Communication.	A multidisciplinary team would ideally be involved in the implementation of tracking. The rationale for tracking should be communicated clearly to athletes, who should also have a say in how their tracking data is stored and used, and who can access it. Ongoing menstrual health education should be provided to both athletes and practitioners. Approaches to tracking should also be flexible to account for differing needs for athletes.
Clarke 2021	AUS	Mixed-methods participatory approach	Identify what male coaches want to know about the MC, and how it influences training and performance.	Male Australian coaches working with female athletes in various football codes (n = 18); Minimum Tier 3.	Not applicable.	Participants wanted to know if athletes would object to daily wellness questionnaires including a section about MCs, how to approach communicating with athletes about their cycles, the impact of MCs on performance, and how to manage training and negative effects of the cycle.	General support could be provided by coaches encouraging athletes to track their cycle to understand how it affects them. Education is important to monitoring and management practices as it should enable athletes and coaches to recognise signs of dysfunction and facilitate discussions between athletes and coaches.
De Souza 2010	CAN & USA	Observational prospective	Determine the prevalence of 1) subtle menstrual disturbances in exercising but regularly menstruating females, and 2) oligomenorrhea and amenorrhea in exercising females.	Exercising females (n = 67), including recreationally active individuals and athletes; Sedentary controls (n = 20); Aged 18–35 years.	Tracking menstruation and daily urine LH, E1G, PdG concentrations.	Out of the exercising females 7.0% were oligomenorrheic and 37.2% were amenorrheic. Of those exercising and regularly menstruating participants, 47.9% had ovulatory cycles, 27% had luteal phase defective cycles and 25% had anovulatory cycles; 5% of sedentary controls had luteal phase defective cycles. None of the sedentary controls either oligomenorrhea or amenorrhea.	In exercising females, MC length is not an accurate indicator of menstrual function as subtle menstrual disorders with regular menstruation are prevalent. Given questionnaires may be unable to capture subtle menstrual disorders, previously reported prevalence of female athlete triad may be underestimated.
Dupuit 2023	FRA	Longitudinal observational	Report a feasible methodological approach to monitor menstrual status in an applied sport setting.	Female soccer athletes (n = 19); Tier 3; Age avg. 23.7 ± 4.4 years; Including OCP users (n = 5) and naturally cycles (n = 14).	Calendar-based tracking via online application (to record symptoms, and menstruation or placebo-pill consumption). Instructed to complete tracking by noon and regular reminders were provided.	Participants captured 5 to 7 complete cycles over a 7-month period and typically an individual's cycle length would vary by 3.5 ± 2.1 days. Adherence (completed days/total monitoring days) and compliance (days completed by noon/total completed days) declined in December and again in March and April, the final two months of season. Adherence and compliance were not influenced by age, playing position, HC use. Participants interest in tracking was correlated with adherence and compliance. Interest was influenced by number of symptoms but not age or HC use. Day of the week had a significant effect on adherence, tracking more commonly incomplete rest days and weekends.	Ovulation testing and basal body temperature measures could be included to identify anovulation and cycle phases, but authors are not advocating for this to become a normal practice, “without prior professional training and appropriate ethical validation.” Tracking may be used to understand the how athletes training and performance are impacted, or identify changes in cycle length and enable further investigation.
Forsyth 2023	UK	Iterative mixed-methods approach	Explore soccer players’, coaches’ and managers’ perceptions of policies and research related to MCs, hormonal contraception, and pregnancy.	Adults involved in soccer in the UK and various European countries; Amateur to professional competitive levels; Athletes (n = 505); Coaches (n = 230); Managers (n = 108); Administrators (n = 79); Other e.g., psychologist, sport scientist, referee (n = 60).	Not applicable.	MC tracking is being implemented in some clubs, but approaches vary with some leaving the responsibility of tracking to athletes and others including it within athlete monitoring programmes or using MC tracking apps. Tracking data was noted by some to be used to modify training (e.g., reduce load). Although, some did not use data in this way due to challenges individualising training for all players who have different cycles. Tracking is also a method that can be used to avoid direct communication about MCs with practitioners. There was a desire from practitioners for education or training related to MCs be delivered from an organisational level rather than club level.	Issues may arise regarding if and how cycle monitoring data is used. Individual monitoring could improve health and performance literacy, and facilitate conversations for improved performance outcomes. The inclusion of this topic within the provision of formal coach education could act as a mechanism to introduce coaches to the importance of this topic. In turn, methods such as MC tracking apps could provide coaches with specific strategies to consider and approach their players and participants on this subject.
Halson 2024	UK	Prospective cohort	Determine whether sleep in elite female athletes is associated with menstrual symptoms or day of the MC.	Regularly menstruating soccer athletes (n = 12); aged 20–32 years (avg 26.2); Tier 3.	Calendar-based method via smartphone application; Tracked days of bleeding and symptoms, by ticking ‘yes’ if experiencing symptom listed regardless of severity.	On average, athletes reported 8 ± 14 symptoms per cycle. Day of MC was related to total symptoms reported, with the most symptoms occurring on day 1 and declining over the rest of the cycle. Sleep duration and time in bed significantly increased with each day of MC, and with an increase in total number of symptoms. There was a significant day × symptom interaction on sleep duration and time in bed that demonstrates the relationship between day of cycle and time asleep or in bed is reduced as the number of symptoms increases. Wake after sleep onset was also positively related to number of symptoms but not day of MC.	MC tracking is encouraged, and the inclusion of symptoms is important to the implementation of MC tracking, due to their association with some sleep related outcomes. The number of symptoms has a more pronounced impact on changes in sleep duration and time in bed than day of MC; therefore, a greater number of symptoms reported by athlete may indicate athletes who are more likely to demonstrate increase sleep duration and disturbances in sleep and could benefit from support to manage to symptoms and promote sleep.
Heyward 2020	UK	Cross-sectional survey	Establish current practices related to physical preparation strategies in female rugby codes.	Practitioners providing physical preparation support to female rugby athletes at any competitive level (n = 37); Age 29.4 ± 5.0 years; Including males (n = 32) and females (n = 5).	Not applicable.	22% of participants reported monitoring MCs in their practice; Eight participants noted the MC was a unique aspect of the physical preparation of female rugby athletes and awareness of the MC's impact on mood, energy, and physical performance, and being mindful of expectations during different times in athletes’ cycles was important.	Recommends MC tracking is integrated into wellness monitoring. Acknowledge that laboratory approaches may not be feasible in applied settings but an individualised approach to tracking cycle phase, symptoms, training load, and wellness could be useful.
Howe 2024	CZE	Conceptual reflection	Highlight how systematic MC tracking (i.e., large-scale tracking managed by a sporting organization) may be harmful to athletes, and provide policy recommendations to mitigate risks of tracking.	Not applicable.	Not applicable.	Overall tracking generally gives even greater power to practitioners over athletes. This has implications on vulnerable athletes (i.e., youth athletes, those in high pressure sporting environments, athletes that are transgender or sex development differences, and pregnant athletes), which needs to be considered. Tracking may reveal information that athletes do not want to share or that athletes were unaware of. Practitioners’ access to data may not be justified where there is not conclusive evidence to demonstrate the MC is relevant to aspects of health or performance they focus on. There is also potential for the tracking data to be misused by practitioners or commodified.	Policy recommendations include: 1) the female athlete, who produces the cycle tracking data, has the right to control that data; 2) athletes must be fully informed of why and how tracking data is collected to provide informed consent and youth athletes must be excluded from systematic MC tracking as they cannot consent; 3) provide education to athletes, coaches, and support staff about the MC, including risks associated with MC tracking ; 4) recognize that systematic tracking could facilitate abusive behaviour; 5) access to tracking data should not be accessible to staff who have not received education on MC and tracking.
Keay 2022	UK	Prospective cohort	Examine the value of using artificial intelligence techniques to model female sex hormone concentrations over the MC, without the constraints of serial blood testing.	Professional female dancers (n = 14); Age 25.5 ± 3.7 years; Including HC users (n = 2).	MC tracking was included in existing monitoring system dancers used to record wellness. Capillary blood samples collected on day 14 and 21 of MC (for non-HC users) and FSH, LH, estradiol and progesterone measured. Artificial intelligence and Bayesian Inference considering the hormone measures at the two timepoints was used to model the hormones throughout the individual's MC (in non-HC users).	Including MC tracking in existing monitoring system was “well-received” by participants. Despite regular menstruation, some participants demonstrated subclinical reductions in female sex hormones in the modelled MC. 3/6 participants that had multiple cycles to compare, showed improved hormonal function after they received personalised training and nutrition advice.	MC tracking with the application of AI modelling techniques enables a proactive rather than reactive approach to identify and manage menstrual concerns.
Keay 2022	UK	Prospective cohort	1) Develop a female football-specific energy availability questionnaire and 2) assess the application of artificial intelligence techniques to model hormone concentrations over the MC.	Professional female footballers (n = 21); Minimum Tier 3; Age 16–30 years; Participants that completed MC modelling (n = 3)	Tracking to record MC length and collect capillary blood samples on day 14 and 21 of MC (for non-HC users) and FSH, LH, estradiol and progesterone measured. Artificial intelligence and Bayesian Inference considering the hormone measures at the two timepoints was used to model the hormones throughout the individual's MC (in non-HC users).	MC tracking apps were used by eleven participants; Two participants demonstrated expected hormonal fluctuations in their modelled MCs, and one showed hormonal disruption indicative of anovulation.	The application of AI techniques to model MCs could be useful in identifying hormonal disruptions that may be missed when tracking MCs via calendar-based methods alone.
Majumder 2022	IND	Cross-sectional survey	Understand 1) MC-related practices, knowledge, communication, and health, and 2) how perceptions of performance and readiness change with MC phase, specifically in Indian endurance athletes.	Indian female endurance athletes (n = 128); Majority at Tier 3 (n = 68); Includes HC users (n = 12); Age 18–35 (avg. 22 ± 3 years).	Not applicable.	45.8% of participants reported they currently tracked their MC, and 67.7% and 70.8% did not change or plan their training based on their MC, respectively. A significantly higher number of athletes reported a positive perception of their sleep quality, readiness to train, fitness, and performance immediately after menstruation, compared to during menstruation.	A training diary could be used to monitor MC and related side effects to support performance, and optimise recovery and training, particularly as different aspects of subjective wellbeing and readiness change over the MC.
McHaffie 2022	UK	Qualitative	Explore athletes, parents, and practitioners’ perceptions of menstrual health related support currently provided in elite soccer.	Female soccer athletes (n = 12); Minimum Tier 3; Not pregnant or using HC; Age range 16–30 years; Parents of players aged 16–18 living at home (n = 9); Support staff, technical coaches (n = 9), sport scientist (n = 7), nutritionist (n = 5), medical staff (n = 5)	Not applicable.	8/12 athletes indicated they tracked menstruation via daily wellness questionnaire. Where tracking was implemented, practitioners were unsure of the purpose of tracking and how to use the data collected, this was attributed to lack of evidence to support decision-making. Additionally, HC status (i.e., if using HC) of athletes was known by two practitioner participants and not often considered. Training modifications were based on conversations between athletes and practitioners rather than tracking data. However, there was a lack of clarity which practitioners should be having these conversations and concerns athletes would be reluctant to communicate. Although, athletes noted they would appreciate the topic of menstrual health being openly discussed.	MC tracking at a personal or club level considered to useful to understand timing of menses, but the follow-up (i.e., the conversations taking place as a result of tracking) is more important. To improve menstrual health support “organisational, stakeholder, and player centred education programmes” are needed to facilitate an environment that enables this communication.
McKay 2023	AUS	Longitudinal observational	Describe 1) the aims, protocols, and implementation a 5-week residential training camp and 2) the menstrual function, hormonal profiles and symptomology of participants, to demonstrate how research can take place within a daily training environment.	Australian First Nations rugby league athletes (n = 24); Tier 3; including HC users (n = 13, avg. age 22.3 ± 2.5 years) and natural cycling (n = 11, avg. age 20.8 ± 3.2 years).	Tracking conducted via daily online survey to record blood flow occurred in last 24 h, if any listed symptoms occurred, and if ovulation test completed or OCP placebo consume. Clearblue Advanced Digital Ovulation Test used day 8 until positive result or day 17 (window extended in some cases); Serum estrogen, progesterone, LH, FSH, GH, testosterone and SHBG measured on three occasions.	99.3% of daily surveys were completed and participants found tracking to be a manageable commitment. Of the 11 naturally cycling participants, they demonstrated anovulation (n = 1), LPD (n = 1), and unusual hormonal profiles (n = 5), oligomenorrhea (n = 3), and eumenorrhea. If LPD participant did not provide blood sample in Phase 2 they would have been classified as eumenorrheic.	Regular menstruation cannot always be used as an indicator of menstrual function and additional measure may be needed. Although “minimum number of samples per cycle, or repeated samples across two cycles” should be clarified as the timing/frequency that samples (i.e., blood samples for serum hormone analysis) are collected may influence the outcome of menstrual function assessments.
Morris 2001	AUS	Non-randomised, control trial	Assess the usefulness and feasibility of an approach to monitor athletes’ ovarian hormone responses to training.	Athletes in a school-based rowing program (n = 14; age 14–15); Adult lightweight rowers (n = 12; age 21.5 ± 3.5 years, Tier 3; Control participants (n = 20); All participants were post-menarcheal, not using oral contraceptives, and in good health.	Urinary E1G and PdG concentrations, (samples collected every second day, diluted by the participants and stored in their domestic freezer).	Compliance was considered to be “high” (specific compliance rate was not reported). Method of longitudinal ovarian hormone monitoring used could detect extremely low E1G and PdG levels. Rowers’ MC length was significantly greater in the competitive compared to off-season (47.9 ± 33.0 vs 28.0 ± 3.0) and compared to the control group. For lightweight rowers, ovulation was restored (n = 9) or maintained (n = 3) in the off-season.	The authors recommend this approach to monitoring is implemented in other sport settings as part of routine clinical practice to manage skeletal health risks in female athletes. This approach is suitable to junior (14+) and senior athletes and could be adapted to suit different field conditions and enable monitoring in more settings.
Roffler 2024	GER	Observational	Examine the occurrence of menstrual symptoms tracked by an elite female volleyball team over two seasons.	Volleyball athletes (n = 20); including HC users (n = 4); aged between 19.2 and 27.7 years (24.5 ± 2.0 years); Tier 3.	Calendar-based tracking via smartphone app; Tracking intensity of bleeding (none-heavy) and symptoms (select from list of 18 symptoms) and ability to add comments in ‘notes’ section; Completed daily before sleep; Menstrual Symptom Index was calculated for non-HC users based on the range and frequency of symptoms experienced.	Stomach cramps were experienced by all, and disturbed sleep, and fatigue were experienced by most (73.3%) athletes on at least one occasion. Symptoms were most often reported during menstruation. On average, athletes experienced 11.8 ± 17.7 symptoms per cycle (count that each type of symptom was experienced). The Menstrual Symptom Index of non-HC users ranged from 1–34 (mean =12.9 ± 10.7) out of a possible 54 points.	Accurate identification of menstrual phases and hormonal fluctuation are not usually feasible in a sporting environment but tracking as described in this study can be used to understand athletes’ needs, develop individualised plans for athletes to promote wellbeing and comfort, and facilitate discussions between athletes and support staff. The Menstrual Symptom Index is also a useful tool to quantify athletes’ experiences of menstrual symptoms, which can be used to by medical staff to understand their needs.
Scott 2024	USA	Prospective cohort	Determine whether MC phase is associated with self-reported fatigue, sleep, and soreness ratings and. the dose–response (i.e., psychophysiological responses) to soccer training and matches prior to and during the 2019 Women's World Cup.	Naturally menstruating soccer athletes with no known menstrual dysfunction (n = 16); Tier 5; aged 28.3 ± 4.4.	Calendar-based tracking included in wellness questionnaire via digital athlete management system; Tracked first day of menstrual bleeding; In addition to tracking, participants completed a survey to provide information regarding menstrual history and symptomology, which was used to develop an individualized plans to address symptoms.	Fatigue recorded 48 h post-match was significantly greater in the luteal compared to follicular phase. No other associations between cycle phase and ratings of sleep, fatigue, and soreness were observed. Significantly higher sRPE was recorded during the luteal phase compared to menstruation when distance covered in the session was ≥5 km. Of the 24 sessions recorded where distance was ≥5 km, only one session was training, and the rest were matches.	A pragmatic approach to MC tracking and estimating MC phases may be useful in applied elite sport settings. Authors hypothesised the null effects on sleep, fatigue, and soreness may be due to high-level of support offered to athletes, including comprehensive female athlete-focussed education and individualised symptom mitigation strategies. Education and individualised symptom mitigation strategies could then serve to limit potential effects of the MC and support well-being and performance in practice. The effect of the MC on the psychophysiological responses to soccer may be more apparent in games or high-volume training sessions. Practitioners should consider MC phase when interpreting sRPE, particularly following games or high-volume training sessions.
Taim 2023	SIN	Cross-sectional online survey	1) Examine menstrual characteristics and 2) the MC's impact on perceptions of training and performance, and 3) identify factors effecting communication related MCs in high-performance female adolescent athletes in Singapore.	Female adolescent athletes from a high-performance sports academy in Singapore (n = 90); Minimum Tier 3; Age 15.4 ± 1.8 years; Multiple sports. Including post-menarcheal (n = 84), pre-menarcheal (n = 2), and OCP users (n = 2).	Not applicable.	51% of non-OCP using participants tracked their MC; MC tracking apps were most popular method of tracking (n = 21), followed closely by electronic/paper calendars (n = 18) and least common was diary/notes (n = 3). 17% preferred monitoring apps as a means of communicating about the MC with practitioners and 37% of participants were interested in receiving education related the MC tracking.	A periodic menstrual health screening approach is recommended by the authors, not MC tracking. MC-related initiatives in youth sport should ideally be age-appropriate, account for individual preferences, and involve parental support.

AMH = anti-mullerian hormone; AUS = Australia; avg = average; CAN = Canada; CZE = Czech Republic; E1G = urinary estrone glucuronide; E13G = estrone-3-glucuronide; FRA = France; FSH = follicle stimulating hormone; GH = growth hormone; HC = hormonal contraception; IND = India; LH = luteinising hormone; LPD = luteal phase deficiency; MC = menstrual cycle; n = sample size; OCP = oral contraceptive pill; PdG = pregnanediol glucuronide; SIN = Singapore; SHBG = Sex hormone-binding globulin; sRPE = sessional rating of perceived exertion; UK = United Kingdom; USA = United States of America.

The non-original research publications (n = 6) (Table 3) largely advocated for further research on menstrual cycle tracking in sport^32–34 and provided suggestions for cycle tracking in research and applied settings.^33,35–37

Table 3.

Non-research publications that fulfilled inclusion criteria.

AuthorYear	Country	Aim	Tracking Methods Described	Conclusion
Badenhorst 2024	NZ	Provide a framework for sporting organizations, coaches, support staff or athletes to support decision-making surrounding menstrual health discussions and monitoring.	A range of variables that may be monitored (i.e., MC duration, symptoms, basal body temperature), how they may be monitored, and considerations for their use are presented.	The Menstrual Health Manager (MHM) includes resources such as decision trees and lay summaries of various hormonal profiles and conditions affecting females. The decision trees and tables provide a framework to help stakeholders decide on menstrual health monitoring methods, understand the data they collect, and make informed decisions.
Bruinvels 2022	UK	Highlight to practitioners and researchers the limitations of phase-based approaches to understanding the effects of the MC and importance of considering day-to-day variations throughout the entire MC.	Acknowledge there are a variety of methods (e.g., paper-based diaries or mobile app) but suggests measuring hormone concentrations, if resources are available.	Provide education to athletes and practitioners to normalise conversations around MC. Recommend tracking to understand how cycle effects an individual and changes that may occur over time, and including hormone measures in this process to identify cycle phase or determine whether expected hormonal fluctuations occur. Alongside tracking, symptom mitigation/management strategies should also be implemented.
Casto 2022	USA	Highlight potential risks related to the implementation of MC tracking in sport.	Not applicable.	MC tracking is irrelevant to large proportion of athletes (i.e., those not menstruating consistently or at all, using hormonal contraception). Tracking and the provision of nutritional or training advice based on tracking is premature, given the inconclusivity or lack of research. Tracking may be beneficial to athletes, but there are also risks to athletes’ autonomy, privacy and safety this need to be considered and caution taken with a top-down approach to tracking. Implementation of tracking should centre on individual empowerment.
Exel 2024	AUT	Provide an overview of the uses of pervasive computing and data analysis for performance optimisation and supporting wellbeing in sport, and a framework for to balance the need standardization and individualization in decision making related to athlete monitoring.	Tracking can take place using a variety of methods: calendar-based counting, basal body temperature recording, and tracking technologies such as smartphone applications.	MC tracking may provide a useful indication of female athletes’ health, but limitations in research surrounding phase-based training and effect of MC on performance should be addressed to understand it's application for performance. A limitation of tracking technologies such as apps are that predictions of ovulation, menstruation onset and MC phase are usually inaccurate. MC tracking is one area where there is an opportunity for improved technology to help develop understanding of how an athlete's cycle relates to their performance and wellbeing.
Julian 2020	GER	Discuss considerations for MC phase-based training periodisation and encourage continued research to bridge the research to practice gap in female football.	Calendar-based calculations of MC phase are not accurate; therefore, diaries and indicators of ovulation (i.e., cervical mucous, ovulation test kits), while less valid and reliable could be useful and feasible in applied settings.	The recommendations for MC tracking in research and applied settings should not necessarily be the same. A cost- and time-efficient tool should be developed in future to enable longitudinal hormone monitoring in applied settings and research should be conducted to validate cost- and time-efficient tracking tools.
Kryger 2022	UK	Highlight the questions that should be addressed to advance technological development in female football.	MC tracking apps and use of urinary ovulation testing and/serum hormonal measures if dysfunction/irregularities suspected.	Question to further development of technological considerations in female football was “How can MC tracking apps be employed to manage elite women footballers’ wellbeing and performance?” Some football teams use MC tracking apps, and then have to manually interpret these data. The implementation of tracking, in addition to screening, related education, and proactive management strategies is recommended to support players.

AUS = Australia; AUT = Austria; GER = Germany; MC = menstrual cycle; NZ = New Zealand; UK = United Kingdom; USA = United States of America.

The concepts relating to menstrual cycle tracking, including the reasons why one might track, how tracking can be implemented, and additional considerations to be aware of, are summarised in Figure 3. The prevalence of menstrual cycle tracking was reported in four studies and was practiced in 22–67% of their population, across youth, ³⁸ endurance, ³⁹ and team^40,41 sports. Twelve of the twenty-six publications suggest or recommend that athletes track their cycles. Numerous publications also encourage practitioners to consider risks and limitations of menstrual cycle tracking (n = 13); this includes three of the aforementioned publications that suggest or recommend tracking.^24,42,43 These considerations include the usefulness (i.e., validity, reliability) of tracking tools (n = 4)^,28,31,33,34 appropriate use of tracking data (n = 4),^35,41,44,45 age appropriateness if working with junior athletes (n = 2),^38,45 whether practice is supported by research (n = 3),^33,35,45 athletes’ autonomy and/or privacy (n = 4),^35,37,45,46 varying cultural views of menstruation (n = 2),^37,46 and the disadvantages of athletes’ focussing their attention on their cycle (n = 2).^42,46 Within the articles included in this review, many (n = 13) recommended athletes and/or practitioners engage in education relating to menstrual cycles^{24,27,28,32,36–39,41,43,45–48} and encouraged more open communication between athletes and practitioners (n = 10).^{24,26,36,38,39,41,43,46–48}

Figure 3.

Summary of why menstrual cycle tracking is recommended or currently takes place, how tracking is currently implemented, and considerations noted to be aware of if tracking based on the results of the existing literature.

Discussion

This scoping review offers an overview of the existing literature pertaining to the implementation of menstrual cycle tracking within applied sports settings. The publications included in this review highlight the progress that has been made in the last two and half decades in this field, the uses and methods of menstrual cycle tracking, the role of education and communication in supporting tracking processes, and the future of menstrual cycle tracking technology.

Progress since 2001

The earliest publication captured in this review was Morris and Wark's ⁵ study in 2001 on serial urine sampling to identify hormone changes in youth and elite adult rowers over a competitive season. The authors recommended their tracking protocol be an “integral part of routine clinical practice” to preserve female athlete's bone health. ^{5 (p.13)} This study was published not long after the female athlete triad was conceived and the consequences of menstrual dysfunction to bone health were more widely understood. ⁴⁹ Despite this, only recently menstrual cycle tracking has gained popularity as an athlete monitoring tool. Current interest in tracking can be evidenced by the large number of articles included in this review that were published in the last two years and reporting of cycle tracking occurring in professional and representative sporting teams in popular media. ¹³

Research investigating the links between menstrual health and other aspects such as bone health, body composition, and energy availability have been summarised elsewhere^50–53 over a longer period of time, and as such, was not a focus of this scoping review. However, this information forms the basis for why menstrual cycle tracking may be relevant for female athletes. The discussion of menstrual cycle tracking by popular media potentially indicates a broader societal shift in the public perception of this topic, a result of greater resourcing with increased professionalisation, or perhaps increased visibility of various sports for female athletes. For example, there were many discussions of how National teams prepared athletes and utilised cycle tracking in media coverage pertaining to the 2023 Women's Football World Cup.^54,55 The prevalence of cycle tracking for athlete monitoring in different settings appears to vary and it remains unknown how widely used menstrual cycle tracking is, specifically as an athlete monitoring tool (i.e., used to support athlete health, wellbeing, and/or performance). Furthermore, there is still little evidence to indicate tracking menstrual cycles leads to improved health or performance outcomes in athletes. Anecdotally, some athletes report benefits of tracking their cycle but whether this has tangible impacts on outcomes related to health or performance needs to be investigated to understand how useful cycle tracking is in applied settings. Specifically, field-based studies investigating the efficacy of tracking in identifying menstrual dysfunction, preventing the development of REDs or bone stress injuries, and assisting in the management of negative side-effects.

While the body of literature on this topic is relatively new, there is also a noteworthy geographical and cultural bias present. With almost all articles originating from Western countries, there is a gap in literature that does not account for the breadth of perspectives on menstrual-related topics that exist globally and across different cultures.^56,57 This bias could point to greater funding and publication opportunities in Western countries. It may also be that cycle tracking is not a research focus outside of these regions due to socio-cultural differences in how female sport participation, ⁵⁸ menstruation, and menstrual health is perceived, or that other topics such as period poverty and menstrual hygiene are priortised. ⁵⁹ It is also important to acknowledge the authors of this scoping review are all white women living and working in a Western country and a limitation of this review is that only English language publications were included.

The uses and methods of tracking

Early publications outlined the potential usefulness of tracking in preventing overtraining, bone density losses, and bone stress injuries via the identification of menstrual dysfunction.^5,60 However, this scoping review highlights there are multiple applications of tracking including improving athletes’ self-awareness, identification and subsequent management of menstrual dysfunction and negative menstrual-related side-effects, and facilitation of conversations between athletes and practitioners. The reasoning behind implementing tracking will likely influence the selection of method(s) used to track cycles. ⁶¹ The calendar-based method of tracking used were conducted with mobile tracking applications or daily questionnaires.^{23,24,31,38,41} These tools provide athletes and practitioners insights into menstrual cycle duration, which is necessary for the identification of amenorrhea and oligomenorrhea, and trends related to positive or negative side-effects experienced (i.e., perceptions of improved/impaired performance, menstrual-related symptoms). However, some menstrual cycle tracking apps also provide training and nutrition suggestions for users at different points within their cycles, which practitioners should consider when selecting tracking tools and warrant further attention in research to understand the subjective and objectives effects this may have on athletes. ⁶²

The tracking of symptoms appears to be a useful inclusion in menstrual cycle tracking systems for athletes as there is a relationship between the number of symptoms and sleep, an important aspect of athlete health and wellbeing. ²⁵ However, when used alone, calendar-based tracking has limited use in identifying conditions occurring early on the menstrual dysfunction continuum (i.e., luteal phase defects or anovulation with regular menstruation). This is notable given subtle menstrual disturbances have been observed in close to 50% of exercising and athletic populations, ²⁸ while within a rugby league squad, seven of the eleven menstruating athletes had subtle disturbances. ³¹ Gold-standard approaches to identifying ovulation (i.e., transvaginal ultrasound) and measuring sex hormones (i.e., serum hormone concentration) to capture these subtle disturbances are cost- and time-consuming, invasive,^33,63 and impractical in sport settings. Less valid and reliable measures could still be useful; as seen in Morris and Wark's study ⁵ serial urinary hormone monitoring was sensitive enough to capture changes in hormone concentrations and ovulatory status over the rowing season, and an athlete moving through the menstrual dysfunction continuum. This method requires storage and transport of samples, and incurs costs associated with consumables and assays, so may not be feasible in all settings. The costs and benefits of tracking with these additional measures, or how the use of these measures could be triaged or used intermittently are likely to need consideration in applied settings.

Compliance with tracking

While the implementation of menstrual cycle tracking can be influenced by constraints such as time and financial costs, another consideration is the impact/usefulness of tracking for practitioners and athletes (i.e., ability to identify menstrual dysfunction, or trends in positive- or negative- side effects), is compliance. Like any athlete self-report measure, menstrual cycle tracking relies on consistent and accurate reporting. Athletes’ compliance with menstrual cycle tracking, conducted with different methods with varying levels of burden, was high in multiple studies included in this scoping review. Overall, 87 and 99.3% of daily tracking questionnaires were completed by athletes across a soccer season ²⁴ and rugby league athletes over a 16 week period, ³¹ respectively. When rowing athletes were required to collect, dilute, and store urine samples every second day, the authors’ considered compliance to be “high”, although a specific value to quantify this was not provided. ⁵ In a similar study with female Australian football players, only 66% routinely collected urine samples every other day across a competitive season. ⁶⁴ Athletes’ level of interest in the nutritional, physiological, and psychological influences of the menstrual cycle reportedly had a significant positive correlation with compliance to calendar-based tracking ²⁴ ; therefore, where tracking is implemented, practitioners should consider how to pique athletes’ interest and buy-in to tracking processes. In studies where compliance is recorded,^24,31,64 it is only done so over a single season or period, hence, it is unknown how interest and compliance may change over a longer term (i.e., multiple seasons).

The role of education in tracking

Providing information on menstrual-related topics is likely to rationalise the use of tracking, and promote buy-in to tracking and open communication between athletes and practitioners. As such, many of the authors of the publications included in this review highlight the need for education about menstrual cycles in sport settings. Athletes and practitioners generally feel their knowledge on these topics is poor or inadequate^43,65 and education was identified as one of the overarching considerations to be made in tracking menstrual cycles in sport. ⁴⁶ Importantly, a link has been established between knowledge and health, as athletes with lower knowledge of menstrual dysfunction are more likely to experience amenorrhea or oligomenorrhea. ⁶⁶ This may be observed because female athletes with an understanding of menstrual health are also more likely to be equipped to discuss these topics and highlight concerns to relevant practitioners. ⁴² Coach and practitioner knowledge in this area should also be addressed, as they are a point of contact for athletes and making decisions regarding the implementation of tracking. Indeed, practitioners involved in cycle tracking within Women's Super League and Women's Championship soccer clubs in the United Kingdom were often unsure of the purpose and application of tracking at their club and whose role it was to discuss menstrual-related concerns with athletes. ⁴¹ Therefore physiology-specific knowledge around the menstrual cycle, contextual knowledge around individuals’ specific roles and where to get further support and information is necessary for athletes and practitioners.

Education interventions have been effective in leading to short-term improvements in knowledge pertaining to menstrual cycles and hormonal contraceptives, ⁶⁷ and female athlete triad and REDs.^68,69 However, athletes and practitioners feel they have limited access to resources to develop their knowledge.^43,65 Systemic changes above a club-level (i.e., sport governing bodies) are an important step in improving the environment female athletes train and perform in; with practitioners noting governing bodies should hold more responsibility in their education.^43,65 Examples put forward by practitioners working with soccer athletes and swimmers include receiving a guide for good practice and including education on these female-specific topics within coaching courses and continuing professional development requirements.^43,65 It appears, at least in some cases, there is room for improvement at an organisational level, despite the first position stand on the Female Athlete Triad in 1997 ⁷⁰ advocating for a proactive approach from sport governing bodies to educate coaches and offer professional certifications to those that have undertaken education. Whilst guidance, factsheets, and education modules are available, for example through the Australian Institute of Sport's Female Performance and Health Initiative ⁷¹ or England Netball and the Well HQ's NetballHer site, ⁷² their reach and uptake are likely limited by a lack of awareness of these resources or being optional elements of practitioner education. Additionally, the longer-term retention of this information and the need for subsequent education has not been observed.

The role of communication in tracking

Providing regular feedback and developing trust between athletes and those with access to data collected are key to improving athletes’ experiences of self-report measures in general. ⁷³ Verrier ⁷⁴ has begun to explore athletes’ perceptions of menstrual cycle tracking, and within a rugby environment athletes believed tracking could enhance relationships between teammates, providing a platform from which athletes can discuss their experiences with each other, as well as between athletes and practitioners, with practitioners being able to approach athletes with more understanding and tracking being an avenue for athletes to flag concerns with practitioners. As previously mentioned, knowledge is an important factor that may influence conversations within the sporting environment; this has been recognised and coaches have shown interest in learning how to approach discussions on these topics with the athletes they work with. ⁴⁸

Some barriers to open communication from athletes include stigma surrounding menstruation and the assumption that coaches are uninterested in or not knowledgeable of menstrual health. ⁷⁵ Some athletes do not discuss their menstrual cycle as they do not believe it negatively impacts their performance or do not believe they have any menstrual related issues. This can be true for some individuals, but in some cases may be a result of limited knowledge, such as the belief that absent menstruation is normal in athletes. ⁷⁶ The role of gender as a barrier or facilitator to communication regarding menstrual cycles is not fully understood. In some studies, gender is not identified as a barrier to communication behaviour,^77,78 but others show it does affect athlete's willingness or comfort to discuss menstrual cycles with their coaches.^43,79 The relationship between communication and education becomes apparent as many of these barriers can start to be addressed via education (i.e., informing those in sport what is normal or not normal in terms of menstrual cycles and related symptoms, beginning to address stigma, and demonstrating coaches and practitioners engaging in education). The efficacy of education interventions in facilitating this communication and promoting buy-in to menstrual cycle tracking processes should be investigated in future research. The barriers and facilitators to menstrual cycle tracking in sport should be further investigated in case there are unique considerations to be made.

Tracking-related risks

While socio-environmental factors and streamlining of tracking processes can be addressed to potentially improve the process and impact of cycle tracking, some publications included in this scoping review highlighted potential risks in tracking menstrual cycles. The concerns highlighted by Casto ³⁵ raise an important point – the question of how to track cycles is being investigated, with seemingly little consideration of whether athletes’ cycles should be tracked by practitioners. Various risks may arise from the implementation of menstrual cycle tracking within athlete monitoring systems, including loss of privacy pertaining to menstrual health and fertility information and mishandling of data by practitioners. ³⁵ Taim et al. ³⁸ also called attention to the importance of the safeguarding of young athletes when considering how to promote open communication related to menstrual concerns, with periodic menstrual health screening rather than regular cycle tracking suggested. Howe ⁴⁵ reinforced these concerns relating to privacy, misuse of data, and safeguarding of youth athletes but extended their exploration of the risks of tracking to other vulnerable athletes, which include those in high pressure environments, those with differences in sex development, or transgender athletes. A number of policy recommendations to address these risks were outlined and include ensuring athletes are aware how and why tracking is conducted so they may give informed consent, excluding youth athletes from tracking, blocking practitioners who have not received education on menstrual health, and risks of tracking from accessing tracking data. ⁴⁵

Future tracking technology

The implementation of menstrual cycle tracking may be impacted by how burdensome reporting processes are for athletes. Streamlined processes for athletes to input responses are crucial for athlete friendly reporting systems that are perceived to be useful and low burden. It has been established that the use of additional tools alongside calendar-based tracking are important to the ability of a menstrual cycle tracking system to identify earlier stages of menstrual dysfunction (and enable earlier intervention) but increase the burden and costs of tracking. Within the publications included in this narrative review, there was a protocol to validate a point of care device to measure urinary hormones and indicate ovulation, ²² and two original research articles on the use of artificial intelligence to model hormone fluctuations over the menstrual cycle.^29,30 This research points to how processes for both athletes and practitioners potentially handling data can be streamlined. These advances in tracking technology can allow serial samples to be collected, using non-invasive methods, which can provide real-time results and negate the need for sample storage. Artificial intelligence modelling could also reduce sample collection frequency, to not only save time but also lower costs of consumables and hormonal assays. Advances in sport-specific tracking technology are being showcased by the partnership between the United Kingdom Sports Institute and Mint Diagnostics, who have developed a point of care device measuring female sex hormones from salivary samples, which is currently being used by sporting organisations. ⁸⁰ Outside of the sport-specific context of this review, wearable devices are also being used in a general population to predict ovulation based on skin temperature^81–83 and artificial intelligence to predict the timing of menstruation and ovulation.^84–86 Further research in athletic populations and the application of fertility research should continue to develop easy to use and cheap, but valid and reliable methods of menstrual cycle tracking in sport settings.

Conclusion

Menstrual cycle tracking is the subject of a recent surge in interest but has been discussed as a potential athlete monitoring tool for more than twenty years. Whilst many publications on this topic recommend tracking be implemented in sport settings and highlight the various arguments for its inclusion in athlete monitoring, such as promoting self-awareness, identifying menstrual dysfunction, and managing menstrual symptoms, some of these publications also draw attention to the potential risks of menstrual cycle tracking, such as loss of privacy or misuse of data. Where these risks can be managed and tracking is implemented, practitioners should consider the purpose of cycle tracking in their setting, what methods of tracking are feasible and suit their needs, and how education may be delivered alongside tracking to improve its outcomes. A one-size-fits-all approach to menstrual cycle tracking is unlikely to be appropriate to all sports, and athletes of different ages and cultural backgrounds, so any guidance developed for practitioners related to tracking should remain evidence-based but flexible. Future research should focus on the development of ecologically valid tracking tools, which are cost- and time-effective, and exploring the current practices to understand use of tracking in sport settings, and the barriers and facilitators (i.e., costs, stigma, practitioner expertise) to menstrual cycle tracking in sport.