ATHENA Project: Advanced Tracking for Health and Enhanced Athletic Performance in Female Athletes

Authors & Affiliations

Abbie E. Smith-Ryan [1,2],  Sam R. Moore [1,2]

[1] Applied Physiology Laboratory, Dept. of Exercise and Sport Science, University of North Carolina at Chapel Hill, NC. [2] Human Movement Sciences Curriculum, School of Medicine, University of North Carolina at Chapel Hill, NC. 

Abstract

Sport has the ability to empower women and girls with 96% of women C-suite executives having played sports, demonstrating that girls who play sports become women who lead. Despite this, female athletes experience increased sport injury burden, resulting in lower quality of life and reduced psychosocial function as early as adolescence (1) with health impairments lasting years into athletic retirement (2). Moreover, a glaring lack of female health education surrounding these issues exists due to a dearth of female specific data (3). The need to better understand physiological processes specific to the female athlete is past due, specifically with the robust body of literature detailing physiological sex differences between male and female athletes. The ATHENA Project will implement advanced monitoring procedures, following female athletes across their competitive seasons to better understand the impact of wellness, training, and resulting adaptations on injury and performance, particularly across the menstrual cycle (MC). Daily, weekly, and seasonal (pre- to post-season) measures will evaluate relationships between external loads, internal responses, and performance and injury. A subset of eumenorrheic athletes will be equipped with wearable tracking devices to capture sleep, recovery, and readiness, along with finger prick dried blood spot samples to measure female sex hormones and inflammatory markers at three points across their MC. This more invasive data will be paired with the daily wellness, training, and injury reports to provide a comprehensive understanding of the physiological impact across menstrual phases. Target enrollment will include four Division I collegiate women’s sports teams to evaluate these outcomes between and across a multi-team cohort (n≈130). The goals of this project are to ultimately reduce injury, improve health and quality of life during and after the female athlete playing career, and provide a usable model of integrated female athlete care and research for other institutions with varied resources.

Introduction

Motivation

Only 6% of sport science research has been done exclusively in women, of which the methodologies are relatively poor (4), clearly demonstrating that female athletes are under-researched, under-funded, and under-valued at every level of sport. The current landscape of sport is unequivocally built upon a default male physiology, while the lack of differentiation in training and performance strategies for female athletes results in greater injury burden and inferior outcomes of long-term athlete development. The menstrual cycle is often cited as a barrier and burden to female-specific sport science research and strategy development. The careful design of the present study aims to leverage the menstrual cycle as a guide to unlocking female athlete potential, reduced injury occurrence, and improved lifelong health outcomes.

Impact/Significance

Results of this study will identify key variables related to female athlete availability, providing a framework for establishing training targets and thresholds specific to the menstrual cycle to shape female specific training approaches and guiding future research. Individual athlete and team availability to train and compete is typically evaluated as a significant predictor of competitive success. The current study is unique in its inclusion of a wide breadth of potential contributors and detractors of availability, including variables related to body composition, key performance indicators of training, daily wellness, menstrual characteristics, training load, and physiological biomarkers. While typically evaluated within silos, a comprehensive approach will allow greater interdisciplinary interventions for improved athlete care. Additionally, the multiple-team approach, while ambitious in practice, facilitates the ability to evaluate these various areas of athlete training, wellness, recovery, and adaptation across a varied cohort with varied metabolic demands, providing a better understanding of outcomes relevant to female athletes in general, as well as the potential for sport-specific considerations. Understanding physiological responses to training, considerate of female physiology, could inform future athlete management protocols for improved performance and reduced injury risk in female athletes and active women, while also providing a model of interdisciplinary collaboration for female athletes at the institution and global level.

Hypotheses/Aims

The specific aims of the present study include: 

1. Identify predictors of individual and team athlete availability (defined as the unrestricted capacity to participate in training and/or competition) across a Division I collegiate multi-team cohort. 
2. Characterize fluctuations in physiological biomarkers across the menstrual cycle to evaluate their impact on individual athlete availability, sport performance, daily wellness, and injury characteristics in a subset of Division I collegiate female athletes. 
3. Explore the various levels of integrated athlete support (i.e., members of the multi-disciplinary support team and related resources) on injury rates and performance outcomes between teams. 

Materials/Methods

Study type

• Observational Study - The present study will employ a prospective study design, female Division I collegiate athletes’ health and performance data will be tracked across a competitive season.

Data collection procedures

 Athletes will be asked to complete a medical history questionnaire upon enrollment. Electronic daily wellness surveys will be used to track fatigue, recovery, soreness, readiness, rate of perceived exertion from training sessions, and menstrual cycle patterns and associated symptoms. Performance will be tracked with publicly available box score reports and biweekly countermovement jumps. Training load will be measured with wearable GPS and accelerometry devices during sport practice and competition. Availability outcomes will be calculated from injury data received from sports medicine. Body composition will be measured using dual-energy X-ray absorptiometry and bioelectrical impedance spectroscopy at pre- and post-season timepoints. A subset of eumenorrheic athletes will be fitted with a wearable ring (i.e., Oura Ring) to track their sleep, recovery, and readiness, along with finger prick blood samples at three timepoints across their menstrual cycle (menstruation, ovulation, pre-menstrual phase). The use of finger prick blood samples were chosen over urine or salivary measures, for their practicality (we would be able to travel and complete sample collection at athletic facilities for subject convenience and to minimize attrition), scientific rigor (allowing for definitive menstrual phase confirmation per recommended methodologies (5), and innovation as this method has not previously been implemented in applied collegiate settings. While some data will be tracked by key athletics personnel per their job requirements (i.e., injury and training load), other outcomes including historical and daily surveys, body composition, wearable ring devices, and finger prick hormonal samples will be collected by the research team. The present research team has demonstrated experience using the listed methods, positive working relationships with the proposed athletic teams, as well as athletic department and ethics approvals (6-8).

Sample

Sample sizes for specific aims 1 and 3 will be based on availability of consenting athletes (estimated target ~130 athletes), with plans to conduct post-hoc analyses of key outcomes related to athlete availability. 

Power for specific aim 2 was calculated using effect sizes of previously published literature evaluating similar biomarkers across the menstrual cycle (9-12), with a combined average effect size of 1.36, an alpha level of 0.05, 80% power, and an assumed correlation of 0.8, the present study would be sufficiently powered with 20 participants. Based on the cost of materials and accounting for potential dropout, we have proposed a budget for three testing kits per each subject (for menstruation, ovulation, and pre-menstrual timepoints), for 16 total subjects. 

Existing data

• Registration prior to any human observation of the data: As of the date of submission, data collection for menstrual cycle tracking is currently in progress in order to have some historical data. Data collection for the primary blood outcomes (finger prick dried blood spot samples) has not begun and is dependent upon funding from this proposal.

Explanation of existing data

Female athletes with eumenorrheic hormonal profiles and high compliance rates of the daily wellness and menstrual tracking surveys will be identified and invited to participate in the subset collection of blood samples. This will allow for homogenous hormonal landscapes and potential attrition of a more costly procedure (blood tests). The study ethics has been approved by the University's IRB. 

Processing and Analysis Plan

1. Identify predictors of individual and team athlete availability (defined as the unrestricted capacity to participate in training and/or competition) across a Division I collegiate multi-team cohort.
   • Pearson bivariate correlations will be used to analyze direction and strength of associations between predictor buckets (wellness, body composition, training load, force profile, menstrual history) and availability outcomes (individual availability and team availability). 
   • Multiple linear regression models will be applied to significant correlations within each predictor bucket. Regression models will be applied across the cohort and within teams.
2. Characterize fluctuations in physiological biomarkers across the menstrual cycle to evaluate their impact on individual athlete availability, sport performance, daily wellness, and injury characteristics in a subset of Division I collegiate female athletes.
   • Separate repeated measures analyses of covariance, covaried for baseline values during menstruation, will be used to evaluate within-subject differences in female sex hormone and inflammatory biomarkers.
   • Pearson bivariate correlations will be used to assess direction and strength of associations between biomarkers and outcomes of availability, sport performance, daily wellness, and injury characteristics. Separate linear regression models will be applied to significant correlation findings.
3. Explore the various levels of integrated athlete support (i.e., members of the multi-disciplinary support team and related resources) on injury rates and performance outcomes between teams.
   1. Compare findings across teams with tiered levels of support.

Budget

Costs

Based on the cost of materials and accounting for potential dropout, we have proposed a budget for three testing kits per each subject (for menstruation, ovulation, and pre-menstrual timepoints), for 16 total subjects. 

References

1. Watson A, Biese K, Kliethermes SA, Post E, Brooks MA, Lang PJ, et al. Impact of in-season injury on quality of life and sleep duration in female youth volleyball athletes: A prospective study of 2073 players. British Journal of Sports Medicine. 2021;55(16):912-6.

2. Cowee K, Simon JE. A History of Previous Severe Injury and Health-Related Quality of Life Among Former Collegiate Athletes. J Athl Train. 2019;54(1):64-9.

3. Cowley ES, Olenick AA, McNulty KL, Ross EZ. “ Invisible Sportswomen ” : The Sex Data Gap in Sport and Exercise Science Research. Women in Sport and Physical Activity Journal. 2021:1-6.

4. Cowley ES, Moore SR, Olenick AA, McNulty KL. “Invisible Sportswomen 2.0”—Digging Deeper Into Gender Bias in Sport and Exercise Science Research: Author Gender, Editorial Board Gender, and Research Quality. Women in Sport and Physical Activity Journal. 2024;32(1).

5. Elliott-Sale KJ, Minahan CL, de Jonge XAKJ, Ackerman KE, Sipilä S, Constantini NW, et al. Methodological Considerations for Studies in Sport and Exercise Science with Women as Participants: A Working Guide for Standards of Practice for Research on Women. Sports Medicine. 2021;51(5):843-61.

6. Cabre HE, Moore SR, Smith-Ryan AE, Hackney AC. Relative Energy Deficiency in Sport (RED-S): Scientific, Clinical, and Practical Implications for the Female Athlete. German Journal of Sports Medicine. 2022;73(7):225-33.

7. Moore SR, Cabre HE, Gordon AN, Smith-Ryan AE. Evaluating Change in Body Composition and Impact of Menarche Across a Competitive Season in Elite Collegiate Gymnasts. Women in Sport and Physical Activity Journal. 2024;32(S1).

8. Blue MNM, Hirsch KR, Pihoker AA, Trexler ET, Smith-Ryan AE. Normative fat-free mass index values for a diverse sample of collegiate female athletes. Journal of Sports Sciences. 2019;37(15):1741-5.

9. Romero-Parra N, Barba-Moreno L, Rael B, Alfaro-Magallanes VM, Cupeiro R, Diaz AE, et al. Influence of the Menstrual Cycle on Blood Markers of Muscle Damage and Inflammation Following Eccentric Exercise. Int J Environ Res Public Health. 2020;17(5).

10. Gursoy AY, Caglar GS, Kiseli M, Pabuccu E, Candar T, Demirtas S. CRP at early follicular phase of menstrual cycle can cause misinterpretation for cardiovascular risk assessment. Interv Med Appl Sci. 2015;7(4):143-6.

11. Vashishta S, Gahlot S, Singh A, Goyal R. Impact of menstrual cycle phases on C-reactive protein concentrations. International Journal of Research in Medical Sciences. 2017;5(3).

12. Thiros A, Van Guilder G. The effects of menstrual cycle phase on performance in endurance runners. International Journal of Research in Exercise Physiology. 2022;10(1):1-22.