Below is a list of research articles and proceedings that are referred to in the sections above, and which inform this guideline.

1. Handelsman DJ, Hirschberg AL, Bermon Circulating Testosterone as the Hormonal Basis of Sex Differences in Athletic Performance. Endocr Rev 2018; 39:803-29. doi:10.1210/er.2018-00020
2. Handelsman DJ, Sikaris K, Ly LP. Estimating age-specific trends in circulating testosterone and sex hormone-binding globulin in males and females across the Ann Clin Biochem 2016; 53:377-84. doi:10.1177/0004563215610589
3. Lee DH, Keum N, Hu FB, et Development and validation of anthropometric prediction equations for lean body mass, fat mass and percent fat in adults using the National Health and Nutrition Examination Survey (NHANES) 1999-2006. Br J Nutr 2017; 118:858-66. doi:10.1017 /50007114517002665
4. Janssen I, Heymsfield SB, Wang ZM, et Skeletal muscle mass and distribution in 468 men and women aged 18-88 yr. J Appl Physiol 2000;89:81-8. doi:10.1152/jappl.2000.89.1.81
5. Neder JA, Nery LE, Shinzato GT, et Reference values for concentric knee isokinetic strength and power in nonathletic men and women from 20 to 80 years old. J Orthop Sports Phys Ther 1999; 29:116-26. doi:10.2519/jospt.1999.29.2.116
6. Bohannon RW, Wang Y-C, Yen S-C, et Handgrip Strength: A Comparison of Values Obtained from the NHANES and NIH Toolbox Studies. Am J Occup Ther 2019; 73:7302205080p1-7302205080p9. doi:10.5014/ajot.2019.029538
7. Lepley AS, Joseph MF, Daigle NR, et Sex Differences in Mechanical Properties of the Achilles Tendon: Longitudinal Response to Repetitive Loading Exercise. The Journal of Strength & Conditioning Research 2018; 32:3070-9. doi:10.1519/JSC.0000000000002386
8. Brinckmann P, Hoefert H, Jongen Sex differences in the skeletal geometry of the human pelvis and hip joint. J Biomech 1981; 14:427-30. doi:10.1016/0021- 9290(81)90060-9
9. Jantz LM, Jantz Secular change in long bone length and proportion in the United States, 1800-1970. Am J Phys Anthropol 1999; 110:57-67. doi:10.1002/(SIC1)1096-8644(199909)110:1<57::AID-AJPA5>3.0.CO;2-1
10. Hilton EN, Lundberg Transgender Women in The Female Category of Sport: Is the Male Performance Advantage Removed by Testosterone Suppression? Preprintsorg Published Online First: 13 May 2020. doi:10.20944/preprints202005. 0226.vl
11. Berman S. Androgens and athletic performance of elite female athletes. Curr Opin Endocrinol Diabetes Obes 2017; 24:246-51. doi:10.1097/M ED.0000000000000335
12. Hirschberg AL, Elings Knutsson J, Helge T, et Effects of moderately increased testosterone concentration on physical performance in young women: a double blind, randomised, placebo-controlled study. British Journal of Sports Medicine 2020; 54:599-604. doi:10.1136/bjsports-2018-100525
13. Lambelet-Coleman D, Shreve Comparing athletic performances: The best elite women to boys and men. Duke Law. https://web.law.duke.edu/sites/default/files/centers/sportslaw/comparingathleti cperformances.pdf (accessed 20 May2020).
14. Lassek WD, Gaulin Costs and benefits of fat-free muscle mass in men: relationship to mating success, dietary requirements, and native immunity. Evolution and Human Behavior 2009; 30:322-8. doi: 10.1016/j.evolhumbehav.2009.04.002
15. Stoll T, Huber E, Seifert B, et Maximal Isometric Muscle Strength: Normative Values and Gender-Specific Relation to Age. Clin Rheumatol 2000; 19:105-13. doi:10.1007/s100670050026
16. Harper Sporting Gender. Rowman & Littlefield Publishers 2019.
17. Pate RR, Kriska Physiological basis of the sex difference in cardiorespiratory endurance. Sports Medicine 1984; 1:87-98. doi:10.2165/00007256-198401020- 00001
18. Morris JS, Link J, Martin JC, et Sexual dimorphism in human arm power and force: implications for sexual selection on fighting ability. Journal of Experimental Biology 2020;223.
19. Thomas JR, Thomas Development of Gender Differences in Physical Activity. Quest 2012; 40:219-29. doi:10.1080/00336297.1988.10483902
20. Quarrie KL, Hopkins WG. Tackle injuries in professional Rugby Union. Am J Sports Med 2008; 36:1705-16. doi:10.1177 /0363546508316768
21. Fuller CW, Brooks JHM, Cancea RJ, et Contact events in rugby union and their propensity to cause injury. British Journal of Sports Medicine 2007; 41:862-7- discussion867. doi:10.1136/bjsm.2007.037499
22. Tucker R, Raftery M, Fuller GW, et al. A video analysis of head injuries satisfying the criteria for a head injury assessment in professional Rugby Union: a prospective cohort British Journal of Sports Medicine 2017; 51:1147-51. doi:10.1136/bjsports-2017-097883
23. Tucker R, Raftery M, Kemp S, et Risk factors for head injury events in professional rugby union: a video analysis of 464 head injury events to inform proposed injury prevention strategies. British Journal of Sports Medicine 2017; 51:1152-7. doi:10.1136/bjsports-2017-097895
24. Cross MJ, Tucker R, Raftery M, et Tackling concussion in professional rugby union: a case-control study of tackle-based risk factors and recommendations for primary prevention. British Journal of Sports Medicine 2017; bjsports-2017- 097912. doi:10.1136/bjsports-2017-097912
25. Tierney GJ, Joodaki H, Krosshaug T, et Assessment of model-based image­ matching for future reconstruction of unhelmeted sport head impact kinematics. Sports Biomech 2018; 17:33-47. doi:10.1080/14763141.2016.1271905
26. Tierney GJ, Simms The effects of tackle height on inertial loading of the head and neck in Rugby Union: A multibody model analysis. Brain lnj 2017; 31:1925-31. doi:10.1080/02699052.2017.1385853
27. Berman S, Hirschberg AL, Kowalski J, et Serum androgen levels are positively correlated with athletic performance and competition results in elite female athletes. British Journal of Sports Medicine 2018; 52:1531-2. doi:10.1136/bjsports- 2018-099700
28. Berman S, Garnier P-Y. Serum androgen levels and their relation to performance in track and field: mass spectrometry results from 2127 observations in male and female elite Br J Sports Med 2017; 51:1309-14. doi:10.1136/bjsports-2017- 097792
29. Karkazis K, Jordan-Young R, Davis G, et Out of bounds? A critique of the new policies on hyperandrogenism in elite female athletes. Am J Bioeth 2012; 12:3-16. doi:10.1080/15265161.2012.680533
30. Lucia A, HOYOS J, PEREZ M, et Inverse relationship between VO2max and economy/efficiency in world-class cyclists. Medicine & Science in Sports & Exercise 2002; 34:2079.
31. Epstein The Sports Gene. Current Hardcover 2013.
32. Fighera TM, Ziegelmann PK, Rasia da Silva T, et Bone Mass Effects of Cross­ Sex Hormone Therapy in Transgender People: Updated Systematic Review and Meta-Analysis. J Endocr Soc 2019; 3:943-64. doi:10.1210/js.2018-00413
33. Maraka S, Singh Ospina N, Rodriguez-Gutierrez R, et Sex Steroids and Cardiovascular Outcomes in Transgender Individuals: A Systematic Review and Meta-Analysis. J Clin Endocrinol Metab 2017; 102:3914-23. doi:10.1210/jc.2017- 01643
34. Singh-Ospina N, of SMTJ, Effect of sex steroids on the bone health of transgender individuals: a systematic review and meta-analysis. academicoupcom
35. Elbers JM, Asscheman H, Seidell JC, et Effects of sex steroid hormones on regional fat depots as assessed by magnetic resonance imaging in transsexuals. Am J Physiol 1999;276: E317-25. doi:10.1152/ajpendo.1999.276.2.E317
36. Gooren LJG, Bunck Transsexuals and competitive sports. Eur J Endocrinol 2004; 151:425-9. doi:10.1530/eje.0.1510425
37. Mueller A, Zollver H, Kronawitter D, et Body composition and bone mineral density in male-to-female transsexuals during cross-sex hormone therapy using gonadotrophin-releasing hormone agonist. Exp Clin Endocrinol Diabetes 2011; 119:95-100. doi:10.1055/s-0030-1255074
38. Wierckx K, Van Caenegem E, Schreiner T, et Cross-sex hormone therapy in trans persons is safe and effective at short-time follow-up: results from the European network for the investigation of gender incongruence. J Sex Med 2014; 11:1999-2011. doi:10.1111/jsm.12571
39. Van Caenegem E, Wierckx K, Taes Y, et Preservation of volumetric bone density and geometry in trans women during cross-sex hormonal therapy: a prospective observational study. Osteoporos Int 2015; 26:35-47. doi:10.1007/s00198-014-2805-3
40. Gava G, Cerpolini S, Martelli V, et al. Cyproterone acetate vs leuprolide acetate in combination with transdermal oestradiol in transwomen: a comparison of safety and Clin Endocrinol (Oxf) 2016; 85:239-46. doi:10.1111/cen.13050
41. Wiik A, Lundberg TR, of ERTJ, et al. Muscle Strength, Size, and Composition Following 12 Months of Gender-affirming Treatment in Transgender academicoupcom
42. Fighera TM, da Silva E, Lindenau JD-R, et Impact of cross-sex hormone therapy on bone mineral density and body composition in transwomen. Clin Endocrinol (Oxf) 2018; 88:856-62. doi:10.1111/cen.13607
43. Klaver M, de Blok CJM, Wiepjes CM, et al. Changes in regional body fat, lean body mass and body shape in trans persons using cross-sex hormonal therapy: results from a multicenter prospective Eur J Endocrinol 2018; 178:163-71. doi:10.1530/EJE-17-0496
44. Auer MK, Ebert T, Pietzner M, et Effects of Sex Hormone Treatment on the Metabolic Syndrome in Transgender Individuals: Focus on Metabolic Cytokines. J Clin Endocrinol Metab 2018; 103:790-802. doi:10.1210/jc.2017-01559
45. Scharff M, Wiepjes CM, Klaver M, et Change in grip strength in trans people and its association with lean body mass and bone density. Endocr Connect 2019; 8:1020-8. doi:10.1530/EC-19-0196
46. Kvorning T, Andersen M, Brixen K, et Suppression of endogenous testosterone production attenuates the response to strength training: a randomized, placebo­ controlled, and blinded intervention study. American Journal of Physiology­ Endocrinology and Metabolism 2006;291: E1325-32. doi:10.1152/ajpendo.00143.2006
47. Chen Z, Zhang Y, Lu C, et Supervised Physical Training Enhances Muscle Strength but Not Muscle Mass in Prostate Cancer Patients Undergoing Androgen Deprivation Therapy: A Systematic Review and Meta-Analysis. Front Physiol 2019; 10:843. doi:10.3389/fphys.2019.00843
48. Hanson ED, Sheaff AK, Sood S, et Strength training induces muscle hypertrophy and functional gains in black prostate cancer patients despite androgen deprivation therapy. academicoupcom
49. Leyk D, Gorges W, Ridder D, et al. Hand-grip strength of young men, women and highly trained female Eur J Appl Physiol 2007; 99:415-21. doi:10.1007/s00421-006-0351-1