Biljana Vitosevic1, Milica Filipović1
1University of Priština in Kosovska Mitrovica, Faculty of Sport and Physical Education, Medical Department, Leposavić, Serbia
Biological Gender in Sport: A Review Paper
Sport Mont 2025, 23(3), Ahead of Print | DOI: 10.26773/smj.251020
Abstract
It is well established that categorizing athletes based on biological sex is a fundamental principle in competitive sports to ensure fairness. However, the inclusion of transgender and intersex athletes in recent years has intensified debates about equality and inclusivity. Referring to physiological differences between the sexes, particularly the hormonal influence on athletic performance, this paper examines key biological and ethical challenges related to gender categorization in sports. A literature review, along with an analysis of existing protocols and case studies, was conducted to assess the implications of gender identity in competitive sports. The methodology involved systematically reviewing peer-reviewed scientific articles, institutional policy documents, and relevant legal cases to provide a comprehensive overview. This approach ensured a balanced synthesis of biological evidence and sociopolitical context. The role of testosterone suppression in transgender athletes is analyzed, revealing that while hormonal interventions can reduce certain physiological advantages, some disparities persist post-transition. Ethical and policy considerations are also explored, highlighting the tension between human rights and the necessity of maintaining competitive integrity and equal opportunities. This paper concludes that while existing policies strive to balance inclusion and fairness, further research into the long-term effects of hormone therapy and potential policy innovations, such as open categories or alternative classification systems, may be necessary to ensure equitable competition in the future. The study underscores the need for evidence-based approaches in shaping sports policies while acknowledging the evolving understanding of gender identity in athletics.
Keywords
gender, performance, sex verification, intersex, fair competition
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References
Batista, R. L., Costa, E. M., Rodrigues, A. de, Gomes, N. L., Faria, J. A., Nishi, M. Y., … Mendonca, B. B. (2018). Androgen insensitivity syndrome: A Review. Archives of Endocrinology and Metabolism, 62(2), 227–235.
Bassett, A. J., Ahlmen, A., Rosendorf, J. M., Romeo, A. A., Erickson, B. J., & Bishop, M. E. (2020). The biology of sex and Sport. JBJS Reviews, 8(3). https://doi.org/10.2106/jbjs.rvw.19.00140
Bermon, S., & Kajėniene, A. (2022). Hormonal treatments for transgender athletes and athletes with a difference of sex development. Drugs in Sport, 27, 13–427.
Bianchi, A. (2017). Transgender Women in sport. Journal of the Philosophy of Sport, 44(2), 229–242.
Bowman-Smart, H., Savulescu, J., O'Connell, M., & Sinclair, A. (2024). World Athletics regulations unfairly affect female athletes with differences in sex development. Journal of the Philosophy of Sport, 51(1), 29–53. https://doi.org/10.1080/00948705.2024.2316294
Eastwood, A., Bourdon, P. C., Withers, R. T., & Gore, C. J. (2009). Longitudinal changes in haemoglobin mass and VO2max in adolescents. European Journal of Applied Physiology, 105, 715–721.
Elbers, J. M., Asscheman, H., Seidell, J. C., Megens, J. A., & Gooren, L. J. (1997). Long-term testosterone administration increases visceral fat in female to male transsexuals1. The Journal of Clinical Endocrinology & Metabolism, 82(7), 2044–2047.
Elsas, L. J., Ljungqvist, A., Ferguson-Smith, M. A., Simpson, J. L., Genel, M., Carlson, A. S., … Ehrhardt, A. A. (2000). Gender verification of female athletes. Genetics in Medicine, 2(4), 249–254. https://doi.org/10.1097/00125817-200007000-00008
Esbjörnsson Liljedahl, M., Holm, I., Sylvén, C., & Jansson, E. (1996). Different responses of skeletal muscle following sprint training in men and women. European Journal of Applied Physiology and Occupational Physiology, 74(4), 375–383.
Fossati, C., Di Gianfrancesco, A., Harper, J., Lima, G., Malinsky, F. R., Wang, G.,… Pitsiladis, Y. P. (2019). Gender Identity and Sports Medicine: Inclusion and equal opportunities for athletes in competitions. Medicina Dello Sport, 72(2).
García-Acero, M., Moreno, O., Suárez, F., & Rojas, A. (2020). Disorders of sexual development: Current status and progress in the diagnostic approach. Current Urology, 13(4), 169–178.
Gooren, L., & Bunck, M. (2004). Transsexuals and competitive sports. European Journal of Endocrinology, 151(4), 425–429.
Grand’Maison, V., Clowater, V., & Hill, L. (2025). Epistemologies of ignorance in constructions of fairness and biology: the online swimming community responds to Lia Thomas’ inclusion in women’s swimming events. Feminist Media Studies, 1–18. https://doi.org/10.1080/14680777.2024.2447818
Hamilton, B. R., Lima, G., Barrett, J., Seal, L., Kolliari-Turner, A., Wang, G., … Pitsiladis, Y. P. (2021). Integrating transwomen and female athletes with differences of sex development (DSD) into Elite Competition: The FIMS 2021 consensus statement. Sports Medicine, 51(7), 1401–1415.
Handelsman, D. J., Hirschberg, A. L., & Bermon, S. (2018). Circulating testosterone as the hormonal basis of sex differences in athletic performance. Endocrine Reviews, 39(5), 803–829.
Harper, J., O’Donnell, E., Sorouri Khorashad, B., McDermott, H., & Witcomb, G. L. (2021). How does hormone transition in transgender women change body composition, muscle strength and haemoglobin systematic review with a focus on the implications for sport participation. British Journal of Sports Medicine, 55(15), 865–872.
Heerdt, D. (2025). Awaiting the Semenya Judgement: Challenges and Trends in the Evolving Sport and Human Rights Remedy Landscape. Centre for Sport and Human Rights. Retrieved July 8, 2025, from https://www.sporthumanrights.org/news/awaiting-the-semenya-judgement-challenges-and-trends-in-the-evolving-sport-and-human-rights-remedy-landscape.
Hilton, E. N., & Lundberg, T. R. (2020). Transgender women in the female category of sport: Perspectives on testosterone suppression and performance advantage. Sports Medicine, 51(2), 199–214.
Horwath, O., Apró, W., Moberg, M., Godhe, M., Helge, T., Ekblom, M…. Ekblom, B. (2020). Fiber type-specific hypertrophy and increased capillarization in skeletal muscle following testosterone administration in young women. Journal of Applied Physiology, 128(5), 1240–1250.
World Athletics. (2018). IAAF introduces new eligibility regulations for female classification. Retrieved Feb 19, 2025, from https:// www. iaaf. org/ news/ press- release/ eligibility- regulations- for- female- classifica.
International Olympic Committee. (2015). IOC consensus meeting on sex reassignment and hyperandrogenism. Retrieved Feb 13, 2025, from https://stillmed.olympic.org/Documents/Commissions_PDFfiles/Medical_commission/2015-11_ioc_consensus_meeting_on_sex_reassignment_and_hyperandrogenism-en.pdf
Imperato-McGinley, J., & Zhu, Y.-S. (2002). Androgens and male physiology the syndrome of 5α-reductase-2 deficiency. Molecular and Cellular Endocrinology, 198(1–2), 51–59. https://doi.org/10.1016/s0303-7207(02)00368-4
Jones, B. A., Bowe, M., McNamara, N., Guerin, E., & Carter, T. (2021). Exploring the mental health experiences of young trans and gender diverse people during the Covid-19 pandemic. International Journal of Transgender Health, 24(3), 292–304.
Kraemer, W. J., Ratamess, N. A., & Nindl, B. C. (2017). Recovery responses of testosterone, growth hormone, and IGF-1 after resistance exercise. Journal of Applied Physiology, 122(3), 549–558.
Kraemer, W. J., Ratamess, N. A., Hymer, W. C., Nindl, B. C., & Fragala, M. S. (2020). Growth hormone(s), testosterone, insulin-like growth factors, and cortisol: Roles and integration for cellular development and growth with exercise. Frontiers in Endocrinology, 11.
Loland, S. (2020). Caster Semenya, athlete classification, and Fair Equality of opportunity in Sport. Journal of Medical Ethics, 46(9), 584–590.
Longa, F. E. (2025). Gender equality within the Sports Legal Framework: A comprehensive analysis and future perspectives. Open Journal of Social Sciences, 13(02), 516–520. https://doi.org/10.4236/jss.2025.132029
Lundby, C., & Montero, D. (2019). Did you know—why does maximal oxygen uptake increase in humans following endurance exercise training? Acta Physiologica, 227(4).
Martínková, I. (2020). Open categories in sport: One way to decrease discrimination. Sport, Ethics and Philosophy, 14(4), 461–477.
Martínková, I., Knox, T., Anderson, L., & Parry, J. (2022). Sex and gender in sport categorization: Aiming for terminological clarity. Journal of the Philosophy of Sport, 49(1), 134–150.
Melo, K. F. S., Mendonça, B. B., Billerbeck, A. E., Costa, E. M. F., Latronico, A. C., & Arnhold, I. J. P. (2005). Síndrome de Insensibilidade Aos Andrógenos: Análise clínica, hormonal e molecular de 33 casos. Arquivos Brasileiros de Endocrinologia & Metabologia, 49(1), 87–97. https://doi.org/10.1590/s0004-27302005000100012
Moustakli, E., & Tsonis, O. (2023). Exploring hormone therapy effects on reproduction and health in transgender individuals. Medicina, 59(12), 2094.
Nattiv, A., De Souza, M. J., Koltun, K. J., Misra, M., Kussman, A., Williams, N. I.,… Fredericson, M. (2021). The Male Athlete Triad-A Consensus Statement From the Female and Male Athlete Triad Coalition Part 1: Definition and Scientific Basis. Clinical Journal of Sport Medicine, 31(4), 335–348.
Ordway, C., Nichol, M., Parry, D., & Tweedie, J. W. (2023). Human Rights and Inclusion Policies for transgender women in elite sport: The case of australia ‘rules’ football (AFL). Sport, Ethics and Philosophy, 1–23.
Pielke, R. (2022). Making sense of debate over transgender athletes in olympic sport. Justice for Trans Athletes, 31–43.
Ritchie, R., Reynard, J., & Lewis, T. (2008). Intersex and the Olympic Games. Journal of the Royal Society of Medicine, 101(8), 395–399. https://doi.org/10.1258/jrsm.2008.080086
Sansonio de Morais, A., Ferreira, G. A., Lima-Silva, A. E., & Gomes Filho, A. (2018). Gender-related cardiac dimension differences between female and male professional soccer players. The Journal of Sports Medicine and Physical Fitness, 58(9).
Santisteban, K. J., Lovering, A. T., Halliwill, J. R., & Minson, C. T. (2022). Sex differences in vo2max and the impact on endurance-exercise performance. International Journal of Environmental Research and Public Health, 19(9), 4946.
Schiaffino, S., & Reggiani, C. (2011). Fiber types in mammalian skeletal muscles. Physiological Reviews, 91(4), 1447–1531.
Scovel, S., Nelson, M., & Thorpe, H. (2023). Media Framings of the Transgender Athlete as “Legitimate Controversy”: The Case of Laurel Hubbard at the Tokyo Olympics. Communication & Sport, 11(5), 838-853.
Senefeld, J. W., Hunter, S. K., Coleman, D., & Joyner, M. J. (2023). Case studies in physiology: Male to female transgender swimmer in college athletics. Journal of Applied Physiology, 134(4), 1032–1037.
Serrat, A., & García de Herreros, A. (1996). Gender verification in sports by PCR amplification of SRY and DYZ1 Y chromosome specific sequences: Presence of DYZ1 repeat in female athletes. British Journal of Sports Medicine, 30(4), 310–312.
Sudai M. (2017). The testosterone rule-constructing fairness in professional sport. Journal of Law and the Biosciences, 4(1), 181–193. https://doi.org/10.1093/jlb/lsx004
Tenforde, A. S., Fredericson, M., Sayres, L. C., Cutti, P., & Sainani, K. L. (2015). Identifying sex-specific risk factors for low bone mineral density in adolescent runners. The American Journal of Sports Medicine, 43(6), 1494–1504.
Tucker, R., & Collins, M. (2010). The Science of Sex Verification and athletic performance. International Journal of Sports Physiology and Performance, 5(2), 127–139.
Welle, S., Tawil, R., & Thornton, C. A. (2008). Sex-related differences in gene expression in human skeletal muscle. PLoS ONE, 3(1).