Female hyperandrogenism and elite sport

Abstract

Emerging evidence indicates that testosterone, which can increase muscle mass and strength, stimulates erythropoiesis, promotes competitive behaviour, and enhances the physical performance of women. Indeed, the levels of testosterone within the normal female range are related to muscle mass and athletic performance in female athletes. Furthermore, among these athletes, the prevalence of hyperandrogenic conditions, including both polycystic ovary syndrome and rare differences/disorders of sex development (DSD), which may greatly increase testosterone production, are elevated. Thus, if the androgen receptors of an individual with XY DSD are functional, her muscle mass will develop like that of a man. These findings have led to the proposal that essential hyperandrogenism is beneficial for athletic performance and plays a role in the choice by women to compete in athletic activities. Moreover, a recent randomized controlled trial demonstrated a significant increase in the lean mass and aerobic performance by young exercising women when their testosterone levels were enhanced moderately. Circulating testosterone is considered the strongest factor to explain the male advantage in sport performance, ranging between 10 and 20%. It appears to be unfair to allow female athletes with endogenous testosterone levels in the male range (i.e. 10–20 times higher than normal) to compete against those with normal female androgen levels. In 2012, this consideration led international organizations to establish eligibility regulations for the female classification in order to ensure fair and meaningful competition, but the regulations are controversial and have been challenged in court.

Influence of Female Sex Hormones on Ultra-Running Performance and Post-Race Recovery: Role of Testosterone

“…Our study showed that the participants’ basal testosterone levels were within the low range of normal testosterone concentrations. This finding is in accordance with previous published data regarding gender-specific differences in sex hormones as a result of ultra-endurance exercise [ 39 , 40 ], and is better explained by the hypometabolic state hypothesis since this endocrine disturbance is characterized by low testosterone levels [ 4 ]. Moreover, in our results, participants with higher testosterone levels showed less strength loss and muscle membrane disruption after ultra-endurance exercise.…”

“…Male sex hormones such as testosterone, dihydrotestosterone, and dehydroepiandrosterone modulate the different physiological mechanisms that are responsible for athletic performance improvement [ 4 , 5 ]. Testosterone binding to the androgen receptor at the surface of the muscle fiber increases calcium release from the intracellular stores, activating different mechanisms that increase the number of muscle fibers and satellite cells, as well as the size of motor neurons [ 6 ].…”

Enhanced Skeletal Muscle Oxidative Capacity and Capillary-to-Fiber Ratio Following Moderately Increased Testosterone Exposure in Young Healthy Women

“…This study provides novel insight regarding the physiological effects of increased circulating testosterone levels on endurance performance in active healthy young women. These results support the body of evidence on the effects of testosterone in women ( Hirschberg et al, 2020 ; Horwath et al, 2020 ) and help to put light on the controversy regarding eligibility regulations in athletes with naturally high testosterone levels and their potential unfair advantage ( Hirschberg, 2020 ).…”

“…Since the physiological effects of androgens may be decisive for performance, it is not surprising that androgens have been secretly used for many years to enhance physical performance ( Franke and Berendonk, 1997 ); androgens remain the most common class of doping agents used by athletes ( IAAF, 2020 ). The apparent sex-based differences in athletic performance are largely attributed to the 10–20 times higher circulating levels of testosterone in men than in women ( Handelsman et al, 2018 ; Hirschberg, 2020 ). Therefore, increasing the circulating levels of testosterone may potentially be more beneficial for improving physical performance in women than in men ( Huang and Basaria, 2018 ).…”

The Transgender Exigency

“…Boys develop stronger arms and wider shoulders, and by eighteen the average boy can throw three times as far as the average girl" (Epstein 2013, 67). Testosterone increases muscle mass and strength, and stimulates the production of red blood cells, so those with higher testosterone levels can use more oxygen than those with less (Hirschberg 2020). "World agegroup records in sprinting are nearly identical for boys and girls at age nine, before puberty, when there is little biological reason for gender segregation in sports.…”