For women, athletes with fT levels in the highest tertile had significantly better performance in the 400-meter sprint, 400-meter hurdles, 800-meter sprint, hammer throw, and pole vault with margins of 2.73%, 2.78%, 1.78%, 4.53%, and 2.94%, respectively (P <.05).4 No such advantage of higher fT was observed in the men’s events.4

“With exception of some rare sports like equestrian, archery or shooting, the governing body of sports will always have to draw a line to separate biological male and biological female competitors,” said Dr Bermon. “Drawing this line, by using serum testosterone and clinical examination is not perfect, but this is the best option available at the moment. It is up to each sport to carefully define how they want to achieve that based on their experience, the specificity of their sports, and the available science.”

Fair and Ethical Means to Determine Eligibility

After puberty, the amount of circulating testosterone in men can rise as high as 30 times the amount in women.1 Because testosterone levels have been associated with advantages in athletic performance, women with abnormally high levels of the hormone are deemed to have an advantage over their competitors.1 Whereas men normally have a range of circulating testosterone of 7.7 to 29.4 nmol/L, women of similar age tend to have levels of 0 to 1.7 nmol/L.1

To allow for the overrepresentation of elite women athletes with high testosterone levels, many experts say the threshold for women should be ≤5.0 nmol/L.1 When testing athletes for eligibility, clinicians should use liquid chromatography-mass spectrometry, a more reliable method compared with testosterone immunoassays.1

Another Troubling Matter for Athletes

With most of the attention focused on doping and sex ineligibility in elite sports, relative energy deficiency in sport (RED-S) may go undetected.5 Simply put, RED-S is the insufficient intake of nutrition in athletes. Although RED-S affects both men and women, female athletes are particularly vulnerable to multiple long-term effects such as metabolic, cardiovascular, gastrointestinal, and psychologic disorders.5

In 2014, the International Olympic Committee recognized the seriousness of RED-S and sought to raise awareness of the multidisciplinary teams that care for elite athletes. The International Olympic Committee’s consensus statement emphasized:

·         Identifying athletes at risk for RED-S by developing validated screenings for sports clinicians

·         Preventing RED-S through educational programs for clinicians, athletes, coaches, and sports organizations

·         Improving the evidence base for RED-S in male athletes

·         Educating athletes, coaches, and clinicians about the long-term consequences of RED-S

·         Developing treatment guidelines and rules for safe “return to play”5

“Clinicians educated in RED-S know to look beyond only bone and menstrual health and performance outcomes of low energy availability in female athletes, and will also assess for the health/performance effects of low energy availability in male athletes,” said Margo Mountjoy, MD, PhD, CCFP, FCFP, FACSM, from McMaster University, Hamilton, Ontario, Canada.

Summary & Clinical Applicability

In cases of women athletes with DSD, officials in elite athletic competition argue that they have significant competitive advantages in speed, endurance, and strength. Opponents, however, say that these women athletes should not be forced to lower their androgen levels to compete.

Limitations & Disclosures



1.      Handelsman DJ, Hirschberg AL, Bermon S. Circulating testosterone as the hormonal basis of sex differences in athletic performance. Endocr Rev. 2018;39(5):803-829.

2.      Sőnksen PH, Bavington LD, Boehning T, et al. Hyperandrogenism controversy in elite women’s sport: an examination and critique of recent evidence. Br J Sports Med. 2018;52(23):1481-1482.

3.      IAAF publishes briefing notes and Q&A on female eligibility regulations [news release]. Monte Carlo, Monaco: International Association of Athletic Federations; May 7, 2019. Accessed May 28, 2019.

4.      Bermon S, Garnier PY. Serum androgen levels and their relation to performance in track and field: mass spectrometry results from 2127 observations in male and female elite athletes. Br J Sports Med. 2017;51(17):1309-1314.

5.      Mountjoy M, Sundgot-Borgen JK, Burke LM, et al. IOC consensus statement on relative energy deficiency in sport (RED-S): 2018 update. Br J Sports Med. 2018;52:687-697.

This article originally appeared on Endocrinology Advisor