USADA Bans Erin Oprea, Who Has Trained Carrie Underwood, for Five Years

The U.S. Anti-Doping Agency has banned Erin Oprea, a Nashville personal trainer whose clients have included Carrie Underwood, for five years after her sample from a local triathlon showed two experimental muscle-building drugs and synthetic testosterone.

USADA announced the ban on Sept. 11, a little over three months after the 49-year-old raced the Music City Triathlon on May 31. She had been provisionally suspended since June 16, so the five years are counted from that date and she cannot enter a sanctioned race until June 2031. Her Music City result is disqualified, as is anything she won from that day on. Oprea has not commented publicly on the sanction.

The lab found ostarine and a metabolite of LGD-4033, also called ligandrol, along with testosterone. A second analysis, isotope ratio mass spectrometry, is used to trace where testosterone came from, and in her case it showed the hormone had been made in a lab.

Oprea spent nine years in the Marine Corps, including two tours in Iraq, before building a personal training business in Nashville. Her publisher’s author biography lists Carrie Underwood as a client since early 2007, along with Maren Morris, Kacey Musgraves and Kelsea Ballerini. She wrote The 4 x 4 Diet, and her subscription app, Pretty Muscles, offers home and gym workouts and weekly meal plans, and has picked up about 3,600 ratings on Apple’s App Store.

Both ostarine and LGD-4033 are selective androgen receptor modulators, or SARMs, and both have been studied as possible treatments for muscle wasting. No regulator has cleared either one as a medicine for people. USADA says ostarine is not in any lawful medicine, and the FDA has never signed off on LGD-4033, so neither can be legally prescribed. They are banned in and out of competition, and USADA warns that they are sold as “research chemicals” and sometimes end up in supplements that do not list them on the label.

Four years is the starting point for a case involving these drugs, and USADA went one year further, pointing to the number of banned substances in her sample and to her “failure to cooperate with the investigation.” The rules allow up to two years on top of the standard ban when an agency finds aggravating circumstances like these. Marathon fans saw the same rule at work in March, when the Athletics Integrity Unit found that Albert Korir, the 2021 New York City Marathon champion, had used the blood booster CERA, with three samples taken in October 2025 showing it. His ban went from four years to six before a one-year reduction for admitting the violation brought it to five.

USADA has not accused Oprea of promoting any banned substance, which sets her case apart from the agency’s previous triathlon sanction, a year earlier. Anthony McCauley, a 46-year-old from Raynham, Mass., accepted a four-year ban in September 2025 in a case that grew out of a whistleblower tip rather than a drug test. USADA found he had possessed and used the peptides BPC-157 and TB-500, and his attempted complicity charge came from social media posts promoting those two and three other peptides, posts that reached people who are themselves subject to drug testing.