Wave Check: The ISA’s testosterone policy hurts all athletes


Back in May, West Australian surfer Sasha Jane Lowerson competed in the longboard division of the Western Australian State Titles at her local home in Avalon. She made headlines this year because she was the first openly trans woman to win a surfing competition. 

The surfing media community, with the exception of a few outlets, handled this horribly. You never really want to scroll through the comments of an Instagram post from Stab Mag or the online forum of Beach Grit because there will always be unwarranted vitriol. But it seemed like the outlets went out of their way to open the floodgates of transphobia when Lowerson won.

The main demographic of the comments on a particularly open-ended Stab Mag post was men, of course. Never do they care more about women’s surfing, or women’s anything, until trans identity comes up. The best are the ones from users like @calistahowardd, saying they “support every lgbtq person but this is so messed up :/,” which, I’m not sure how that makes any sense. Some of the worst came from competitive surfers themselves, defaulting to tired and repeated misconceptions about “biological fairness.” 

Before we mention those misconceptions, it’s important to note that the Western Australian State Titles was not the first competition Lowerson ever competed in. She placed 10th in the Noosa Festival of Surfing back in March. Nothing but radio silence when she lost.

The biology arguments have come back into the conversation as the International Surfing Association just released their guidelines for trans athletes last week. The ISA opted for testing testosterone levels and requires that trans women to show the ISA Medical Commission “that her serum testosterone concentration has been less than 5 nmol/L (nanomoles per liter) continuously for a period of the previous 12 months” to compete in the women’s division. The ISA did not say how athletes would be tested, how often they would be tested or specify other possibly critical details.

Testosterone is a sex hormone important to the development of reproductive organs in men, and ovarian function in women. For all genders, the hormone has effects on metabolism, liver function, bones and muscles. “Normal” value ranges in testing happen because different labs use different testing methods. The usual range is 10 to 35 nmol/L in cis men, and 0.5 to 2.4 nmol/L for cis women. Conditions such as inherited adrenal gland disorders, polycystic ovary syndrome (affecting 6-12% of people in the United States) and hirsutism can cause naturally higher levels of testosterone in women. 

During the Western Australian State Titles and beyond, Lowerson reported that she was “running at 0.5 [nmol/L].” It is invasive that many people were demanding this sort of information, but it is by no means a novel phenomenon.

In 2019, South African Olympic middle-distance runner Caster Semenya lost a case against the International Association of Athletics Federations when the Court of Arbitration for Sport ruled that female athletes with naturally high levels of testosterone could not compete in women’s divisions unless they reduced the level of the hormone in their bodies. This effectively demanded athletes like Semenya to go on medications with unknown side effects. 

The decision to discriminate against athletes like Semenya for uncontrollable natural processes contradicts the IAAF’s own analysis on the link between testosterone and performance in women’s track and field. In their study of 1,100 women competing, in three of 11 of the running events, women with lower levels of testosterone performed better than those with higher levels. 

But Semenya wasn’t alone – Namibian track stars Christine Mboma and Beatrice Masilingi, who held four of the five top 400m times in the world in 2021, were banned from the Tokyo Games for naturally high levels of testosterone. They were instructed to take medicine to be able to compete in middle-distance races.

“I wouldn’t want to involve any other things because this is the way my body functions in its normal way,” Masilingi told the BBC. “And if I try something else, I might get caught somewhere else, and something might go wrong with my body.”

To give testosterone the sole credit for athletic prowess is ignoring its natural variances and how it functions in the body. In a 2004 study from the Journal of Sports Sciences, male elite amateur weight lifters had higher testosterone levels for more explosive strength, while male elite cyclists had lower testosterone than the weight lifting and non-athlete groups, but were on top for endurance performance. 

Basing the ability to compete or not on the variance of a natural hormone that is one ofin many factors determining athletic performance is not a strong or fair basis for anyone in any sport. 

In competitve surfing, many forget that cisgender women are not treated the same as men to this day. It was only last year that women were able to compete at Pipeline in a Championship Tour event. This was based largely in the belief that women could not handle a heavy wave like that, even though women have been charging for years on the North Shore. Many people have to realize that these same ideas about cis women, which are just as prevalent and pervasive, are being recycled to demonize trans women.