Officials Checking Female Cyclists For Padded Bras To Make Sure They’re Not Cheating

The International Cycling Union (UCI) may subject Tour de France Femmes riders to more rigorous clothing checks amid concerns that cyclists are illegally padding their bras for an aerodynamic advantage.

The UCI reportedly issued a specific warning about clothing that “could modify riders’ morphology.” Wielerflits, which first reported the story in Dutch, pointed to several instances in which female cyclists appeared to have noticeably larger busts during time trials than during road races.

The outlet highlighted one rider at the 2024 Paris Olympics whose bust appeared larger than usual and showed the photo to Bert Blocken, a professor of aerodynamics at Heriot-Watt University in Scotland and LUT University in Finland.

“That is not OK,” Blocken said.

“Chest fairing” involves placing material inside a cyclist’s jersey to alter the shape of the chest. The modification redirects airflow around the rider’s body, reducing pressure on the thighs and lowering aerodynamic drag, according to Wielerflits and CyclingNews. The reduced resistance can help cyclists ride faster.

Chest fairing can provide an aerodynamic advantage to both male and female cyclists, and several sports governing bodies—including some in cycling—have banned the practice. At the 2025 World Championships in Rwanda, however, Belgian riders reportedly wore their radios on their chests rather than their backs without being penalized. Cyclists have also tucked water bottles inside their jerseys, though the UCI has begun cracking down on that practice, according to CyclingNews. (RELATED: Seattle Storm Suspends Co-Owner For Yelling At Young Fans Holding Signs Supporting Women’s Sports)

According to CyclingNews, UCI officials issued an additional warning ahead of Monday evening’s time trial after Wielerflits published its report.

“Particular attention will be paid to compliance with article 1.3.032 of the UCI regulations, including nonessential elements and clothing or other items/accessories worn by a rider (including but not limited to helmets, glasses, shoes or in-race communication devices) which could modify riders’ morphology,” the announcement said.

“Clothing and other items or accessories worn by a rider (including but not limited to helmets, glasses, shoes or in-race communication devices) may not modify the morphology of the rider,” UCI’s article 1.3.032 states. “Moreover, any non-essential element which is added on (or under) or integrated in any clothing, or other item or accessory worn by a rider shall be forbidden.”

CyclingNews noted that enforcing a ban on extra padding could prove difficult. According to Wielerflits, some team members suggested having a female official inspect riders’ bras inside a private tent. The UCI, however, does not currently regulate bra padding or support, since women require varying levels of both.