Staff | Personal Trainer | Training Gym

ZenRock’s staff has been carefully selected to represent the very best in their respective fields. Our professional certified trainers are guided by a steadfast belief that one-on-one training in a private studio – devoid of distractions – is the optimal way to achieve significant, long-lasting results. We encourage you to learn more about each of our trainers by clicking on their photos below.

PETRA JAHN
Owner, Trainer & Yogi
BELLEVUE & REDMOND

Petra Jahn founded ZenRock Fitness in 2008 to create a safe, inclusive space where people of all backgrounds and abilities could feel empowered through movement, education, and personalized care. A lifelong athlete and former collegiate basketball player, Petra turned to yoga in 2000 to help manage the demands of school, sports, and work. That experience reshaped her approach to fitness—from chasing performance to pursuing lifelong vitality and connectedness.

With over two decades of experience, Petra blends strength training with yoga and mindfulness to help both men and women build strength, reduce pain, and feel connected to their bodies. Her certifications include a 500-hour yoga teacher training and mindfulness certification from 8 Limbs Yoga, as well as Dr. Stacy Sims’ specialized training in perimenopause and menopause. She’s passionate about educating herself and clients, supporting healthy aging, and preventing injury with smart, compassionate coaching.

For more than a decade, Petra—alongside new co-owner Nova Guthrie—has led transformational yoga retreats both nationally and internationally. Together, they’ve created unforgettable experiences that foster deep connection, personal growth, and lasting memories. Retreat destinations have included Bali, Tuscany, Portugal, Costa Rica, Greece, Croatia, and U.S. gems like Zion National Park.

In 2022, Petra and Nova expanded ZenRock by opening a second location in Bellevue, WA, continuing their shared commitment to building a vibrant, supportive community where strength, mindfulness, and holistic wellness come together.

Professional certifications:

ACE-Certified Personal Trainer
200+500-Hour Yoga Teacher (8 Limbs)
Mindfulness Certified (8 Limbs)
Perimenopause & Menopause Certified (Dr. Stacy Sims)
CPR/AED & First Aid Certified

Nova Guthrie: General Manager, & Retreat Coordinator

Nova Guthrie is the General Manager of ZenRock Fitness in Redmond and serves as the Retreat Coordinator, bringing a wealth of experience in fitness, yoga, and wellness coaching – as well as global retreat experiences. With a passion for strength training, conditioning, and yoga, Nova has dedicated her career to helping individuals achieve balance, flexibility, and overall well-being.
Her journey in fitness began with a deep appreciation for pushing physical limits, but she later discovered the importance of recovery and holistic wellness. This led her to embrace yoga as a complement to strength training, allowing her to guide others toward sustainable health practices that nourish body, mind, and soul. In 2013, Nova found a home at ZenRock Fitness and a kindred spirit in Petra Jahn.
At ZenRock, Nova plays a pivotal role in matching clients with the right trainers and ensuring that every individual finds the best combination of wellness tools to live their healthiest, happiest, and most authentic life. Together, Petra and Nova organize yoga adventure retreats all around the globe further enhancing a deeper sense of community for their clients.

Professional Degrees & Certifications:

ISSA – Certified Master Trainer
ISSA – Transformation Specialist Coach
Yoga Fitness Yoga Instructor
BS in Biology – Morningside College
Fitness Therapy & Corrective Exercise Certified
Fitness Nutrition Certified
CPR/AED Certified

Mehdi Ansari: Personal Trainer (Languages: English & Farsi)

As a child I was extremely passionate about fitness and my family teased me for it. I was reading fitness magazines and writing workout plans as a small boy while spending every other moment playing soccer with my cousins. By the time I was a teenager, when not in class, I could always be found in the gym. After serving a mandatory 2 years in the Iranian military, I came to the United States where I earned my BS in Exercise Science. At the same time, I trained vigorously in mixed martial arts and began competing in bodybuilding.

Overall my intent and ambition is to help others develop fitness through education and movement. I love helping my clients define health goals and then creating interesting and engaging workout plans achieve them. I am comfortable guiding my clients through yoga poses and martial arts reps, and always safely. I also integrate bodybuilding techniques and am always willing to train aspiring competitive bodybuilders. Over the years I have successfully established a wonderful and loyal clientele and love the way they enrich and teach me every day!

Professional Degrees & Certifications:

National Strength and Conditioning Association (NSCA) Certified
Associate of Applied Science in Exercise Science
CPR/First Aid Certified

Irina Rutherford: Personal Trainer (Languages: English & Russian)

I owe the overall success of training about 3,000 clients – aged 15 to 95 – with all sorts of fitness level and conditions, both pre- and post-surgery, and patient safety by performing treatment-related exercise programs and/or patient-related tasks. I have had clients in a wheelchair, with ankle arthrodesis (ankle fusion), poliomyelitis, knee replacements, torn meniscus, hip replacement, shoulders, rotator cuff, spinal issues, herniated discs, scoliosis, kyphosis, Harrington rods (metal rods in the spine), stenosis, Parkinson’s, diabetics, Polio…you name it.

My clients are very successful in reaching their goals of losing weight, building muscle mass, increasing endurance, learning proper form, or gaining greater control and flexibility in movement. I am proud to share that I build strong, long-lasting rapport with my clients/patients.

Professional Certifications:

NASM Certified Personal Trainer
AFAA Group Instructor & Personal Trainer
Nutrition Coach
CPR/AED Certified

HEIDI ELLIS
Personal Trainer
BELLEVUE & REDMOND

Heidi Ellis: Personal Trainer

Heidi has fifteen years of personal training experience, with ten of those years at ZenRock Fitness. Heidi loves working with all kinds of people, helping them feel better and gain the ability to enjoy more physical activities. Her clientele ranges from very fit individuals to people needing extra care in their routines.

Heidi has loved fitness her entire life! Her passion developed while doing step aerobics in the living room with her mom and a Jane Fonda workout VHS. Now, she loves working out, spending time in nature, gardening, and nutrition. When she’s not at ZenRock, Heidi enjoys spending time with her husband and daughter, laughing with friends and family, playing with her chickens, and volunteering at the church she attends.

Professional Degrees & Certifications:

BS, Health Promotion & Wellness
CPR/AED Certified

Damithia Nieves: Yoga Instructor

Hi, I’m Damithia! I was introduced to yoga a little over 20 years ago and it has been a part of my life ever since. As an advocate for self-care and community healing, I am committed to disrupting dominant narratives that hinder our personal and collective growth. I bring this same energy to my classes.

My teaching style is grounded in a healing-centered methodology that is built on the belief that the body is a gateway to remembering one’s wholeness. I offer a variety of yoga styles including Trauma-sensitive yoga, Restorative, Hatha, Vinyasa and Chair yoga. Classes incorporate breathwork, meditation and mindfulness techniques with asana (physical postures) to provide a complete practice.

My goal is to provide an experience that centers each person’s individual needs and goals by creating a container of support and care.