Russian figure skater Kamila Valieva tested positive for trimetazidine, a banned drug. Here's what that is.

• Russian Olympic figure skater Kamila Valieva tested positive for trimetazidine, a banned substance
• The drug is used to treat heart conditions by boosting blood flow, potentially aiding athletes' endurance.

Russian figure skater Kamila Valieva tested positive for trimetazidine, a medication used to treat a heart condition and banned from sports competition because it can boost blood flow and endurance.

Valieva, 15, helped contribute to the Russian figure skating team's gold medal win at the Beijing Winter Olympics. However, a World Anti-Doping Agency (WADA) lab later found evidence of the banned substance in a blood test Valieva submitted in December 2021, CNN reported.

Trimetazidine is typically used to treat angina, chest pain associated with coronary heart disease. It works by improving blood flow without increasing the heart rate and keeping blood pressure stable. It may help benefit athletes by preventing a lack of oxygen in the tissue during exercise, staving off fatigue in endurance sports.

It's not clear why Valieva was using the medication, or if she will be allowed to compete at upcoming events.

Trimetazidine has been banned in sport since 2014, as it may enhance endurance

WADA categorizes trimetazidine as a banned substance, listed as a "hormone and metabolic modulator" since 2014, which means athletes who compete at the Olympics are prohibited from using it.

Research suggests the drug can aid in exercise by improving blood flow, which can be useful for endurance sports where athletes need to maximize circulation to help ward off fatigue.

"What this drug does is actually make your heart work more efficiently," Dr. Elizabeth Murray, pediatric emergency medicine physician at the University of Rochester Medical Center, told CNN.

Athletes have previously been suspended for using the drug. In 2014, Chinese swimmer Sun Yang tested positive for trimetazidine. His first-place finish at Chinese Nationals was overturned and he was prohibited from participating for three months. Yang was reportedly taking the drug under the advice of his doctor to treat chest pains. He claimed he was unaware it was prohibited, since it had been newly added to the banned substances list, which wasn't published in Chinese, the Sports Integrity Initiative reported.