To look at 21-year-old Mauri Reyene Peterson, you’d never guess the battles she’s had to fight to achieve the shape she’s in. Peterson, who lives in San Marcose, CA, works as a personal trainer at Equinox Fitness and is a nationally ranked NPC bikini competitor. But reaching and maintaining this super fit lifestyle hasn’t been easy.

Peterson has loved working out since her early teens, when her mother bought her a membership to a local gym. But around this time, she began passing out in school. Doctors chalked it up to low blood sugar, but when one fainting spell was followed by a seizure, she was rushed to the ER, where a cardiologist discovered she had prolonged QT/Sudden Arrhythmia Death Syndrome (SADS). The chronic condition occurs when the heart’s electrical current is not strong enough to maintain a rapid heartbeat. Doctors say most patients don’t survive longer than 10 years after diagnosis.

Peterson had immediate surgery to implant a defibrillator that would help keep her heartbeat regular. But after the condition was diagnosed, doctors recommended she stop exercising. “My heart arrhythmia is triggered by three things—exercise, emotional issues, and stress,” she notes. But exercise is an especially strong risk factor. “When I elevate my heart rate, the muscles are not strong enough to maintain that rapid heartbeat or pace it back down correctly.”

But despite these potentially life-threatening concerns, Peterson was determined to keep doing what she loved. At 18, she received her personal training certification and thrives on seeing how her clients can incorporate life-transforming changes. She entered her first fitness competition last year, which brought its own set of challenges. The fat burners and pre-workout stimulants that competitors often use to help get stage-ready are strictly off limits, and her cardio must stay very light—pushing her to no more than 100 beats per minute (equivalent to a fast-paced walk). “I can’t get that adrenaline rush from exertion. Plus, at some point I’ll need another surgery to stop the defibrillator from slipping out of its ‘pocket.’ ”

SEE ALSO: The Guide to Your First Bikini Competition

Competing isn’t about winning for me—it’s about meeting new people and sharing experiences.

Against the odds, Peterson won her first competition, the Ms. Muscle Beach contest at Venice Beach, CA, in 2015. “It was such a surreal moment,” she recalls. “I knew that I could help other women realize their potential and experience the same feelings of accomplishment.” She went on to compete in two more NPC competitions, placing third in both and qualifying for the national championship in Las Vegas, where she placed 12th out of 49. “Competing isn’t about winning for me—it’s about meeting new people and sharing experiences.”


Peterson has no plans to step off the stage or away from fitness anytime soon. “My feeling is if I don’t compete now, I might not be healthy enough to do so in the future.” She continues to work closely with her doctors to ensure her safety when training, and she hopes that her story will inspire others to pursue their goals. “Anyone can overcome the toughest obstacles. You simply can’t allow fear to get in the way of trying to achieve your dreams,” she maintains. “I want to continue to do what makes me happy and share that with the world.”

How She Does It

In the gym: A five-to six-day-a-week split routine.
Cardio: A brisk 20-minute walk, three times a week.
Favorite moves: Pullups, shoulder presses.
Diet: “I compensate for doing only minimal cardio with a very disciplined diet.”
Go-to clean meals: Grilled salmon with roasted vegetables or protein pancakes.