Bethany Hamilton says she'll boycott World Surf League events over transgender competitors

Professional surfer Bethany Hamilton said she does not intend to participate in upcoming World Surf League events after the organization announced a change in policies that will allow transgender women to compete in women’s events.

In two different videos shared to Instagram this week, Hamilton said she believes she is speaking up for other pro surfer women who fear being “ostracized” for having the same opinions.

The World Surf League this month announced plans to adopt the International Surfing Association’s policy, which requires trans athletes seeking to compete in the women’s division to maintain a testosterone level less than 5 nonomoles per liter (nmol/L) for the previous 12 months.

In her video, Hamilton questioned this policy.

“Is a hormone level an honest and accurate depiction that someone indeed is a male or female? Is it as simple as this?” she asked.

In her follow up video, she questioned the policy again: “Am I just a hormone number? Is it as simple as that?”

Hamilton argued that moving forward with these policies in surfing would allow for “male-bodied dominance” seen in other “women’s sports like running, swimming and others.”

Multiple studies in recent years have looked at whether transgender athletes have competitive advantages. Joanna Harper, a competitive runner and medical physicist who is transgender, published a first-of-its-kind study in 2015 that looked at eight trans women runners who took treatments to lower their testosterone levels and found they did not perform better in several women’s races than they did in men’s races.

A newer 2021 study published in the British Journal of Sports Medicine, however, conducted fitness tests with 29 trans men and 46 trans women and found that trans women retained an athletic edge over their cisgender peers, even after 12 months on hormone therapy.

Harper, who continues to study athletic performances of transgender people and serves as an adviser to the International Olympic Committee, told OutSports in 2021 that most research has nuances, including her own studies, and said conversations should be had in the greater context of sports as a whole.

The debate over trans athletes competing in women’s sports appeared in headlines last year when Lia Thomas, a trans woman, participated in and won an NCAA swimming championship for her school, the University of Pennsylvania, where she previously competed on the men’s team. Also, in 2021, trans runner CeCe Telfer was barred from competing in the women’s 400-meter hurdles at the Tokyo Olympics for not keeping her testosterone levels below the required 5 nonomoles per liter for a span of 12 months, as per the World Athletics’ guidelines.

Transgender athletes have been allowed to participate at the Olympics since 2004, but until the Tokyo Games, none had done so openly, The Associated Press reported at the time.

As for the sport of surfing, BuzzFeed News pointed to surfer Sasha Jane Lowerson, the first openly trans woman to win the women’s open in Australia in May 2022, as the impetus for WSL to implement this policy on trans women surfers.

Hamilton — who is well-known for her memoir “Soul Surfer” and losing her left arm in a 2003 shark attack only to return to the sport — concluded one of her Instagram videos with the suggestion that a separate division be created for trans women, “so that all can have a fair opportunity.”

This article originally appeared on Today.com.

This article was originally published on NBCNews.com