Zach Guza


I started Black Dog Fitness so that no one else has to go through what I did with mental illness and what dad had to go through with Parkinson’s disease.

I struggled with undiagnosed Depression for years.  I just thought that life was supposed to be terrible.  I finally realized what was wrong when I saw a video called “I have a black dog and his name is depression.”  That was me. I have a black dog. 

I have Depression.

When I finally got professional help, one of the first things my psychiatrist told me was, before she would even consider medication, I had to get back to exercising.  Today, regular exercise is a non-negotiable part of my life and is essential for balancing the demands of being a husband, a father, a business owner, and someone who suffers from depression.

Zach Guza knoxville personal trainer, knoxville boxing instructor

So, why Parkinson’s disease?

My dad had Parkinson’s Disease but he was never told that exercise would help him live longer, happier and healthier. His doctors either didn’t know or appreciate the power of exercise.  Because of that he suffered a terrible, steady decline until his death in 2013. 

Hundreds of studies have shown that exercise can slow, stop, and even reverse the symptoms and progression of Parkinson’s Disease.  I wish that my dad would have had a place like Black Dog Fitness. 

I started Black Dog Fitness and Rock Steady Boxing Knoxville so that no one else has to go through what my dad did.


  • United  States Air Force Academy
    • BS – Human Factors Engineering
  • Air Force Officer & Helicopter Pilot
  • Certified Personal Trainer WITS Education

Our Instructors

All of our Instructors and Trainers “organically” found their way to Black Dog Fitness.   We all have come to Black Dog Fitness to make a difference with a creative and positive environment that encourages functional health and community for people who are otherwise left out of fitness.

Coleen Martinez

NeuroMoves, Personal Trainer and Chatty Sparkly Walking Club

Coleen is one of our new trainers. She was born and raised in Almost Heaven, West Virginia and has lived in Florida, Utah, Texas, and now Knoxville for the past 12 years. Coleen has degrees in Dance, Exercise Science, Health Education & Behavior (Adapted Physical Activity), and Therapeutic Recreation. Coleen is a Certified Exercise Physiologist, Recreation Therapist, running coach, and in-training for Dance for PD™ instructor. Coleen teaches NeuroMoves and Chatty Sparkly Walking. Coleen is also available for Personal and Small Group Training.

In her free time, Coleen enjoys running, swimming, cycling, meditation, yoga, hiking, reading, and spending time with her family (most of the time, her family does those activities with her)! 

Sarah Lamont

Spin and Stretch, Personal Training, Rock Steady Boxing Assistant Coach and Yoga

Sarah is a Certified Personal Trainer, Certified Yoga Instructor and Certified Spin Instructor.  She currently teaches Spin and Stretch and Yoga.   She also does personal and small group training.

Perle Sorah

Rock Steady Boxing Coach

Perle has worked his way all the way through teh Rock Steady Program.  He was diagnosed with Parkinson’s Disease in May 2013, after exhibiting symptoms for many years.  He retired from his job after 45 years as a Radiologist Technologist on Friday and started boxing the following Monday.

After about eight months as a fighter, Perle approached Zach about volunteering to help with the stage three and four fighters.  Interested in still doing more, got Certified as a Rock Steady Boxing Coach in January 2018 and has been Zach’s “co-coach” since.

In his “spare time”, Perle and his wife camp, kayak and hike as often as time permits.  He is an avid woodworker and has built everything from small wooden bowls to major cabinets and furniture pieces.

His philosophy for life is keep moving or you just might die.

Mike Nawalany

Personal Training and Rock Steady Boxing Assistant Coach

Mike joined us in May of 2024 as our Assistant Coach for the Rock Steady Boxing Blue Team.  Mike is a certified Occupational Therapist.

Alicia Mau

Personal Training and PWR!

Alicia recently joined the Black Dog Fitness team.  After nine years working as an occupational therapist, she wanted to turn towards disease prevention and maintenance, and healthy aging. Black Dog Fitness was like the perfect fit!

She tailors workouts to each individual client, but has particular interest in balance, grip strength, fall prevention, and pain management.  In her free time, she likes to hike and swing dance as often as possible.

Alex Fellers

Personal Training, Rock Steady Boxing Assistant Coach

Alex and her husband Ryan just moved to Maryville from West Texas. Alex got certified as a Personal Trainer to help people lead healthy, independent, and fulfilling lives. Her passion for wholesome and healthful living was solidified when she was diagnosed with Rheumatoid Arthritis, at only 18 years old.  She was staring down a lifetime of daily medication cocktails – all of which only served to mask symptoms or counteract side effects. But, in a miraculous turn of events, her family physician introduced her to The Plant Paradox by Dr. Steven Gundry and a completely different approach to disease management and treatment. Years later, she is still medication and symptom free.  When she isn’t at the gym, Alex enjoys hiking, paddle-boarding, and mystery novels.

Taylor Morgan

Physical Therapist

Taylor is our in-house Physical Therapist.  She came to us after several years in the “mass production” physical therapy world.  She works with MovementX Physical Therapy to see patients at Black Dog Fitness.  

Taylor’s whole-body and whole-mind approach to physical therapy fits in perfectly with what we do. She is a dedicated and compassionate physical therapist with a profound passion for treating patients with Parkinson’s disease.  Taylor believes that genuine healing encompasses not only physical symptoms but also emotional, psychological, and social well-being.   Taylor is an exceptional Physical Therapist.  Many of our staff and their families see her for treatment.  Click here to schedule a free 15 minute consultation.

Taylor has become a valuable part of the BDF team.  We can stop in for a quick “what-do-you-think” or set up a full cooperative plan between Taylor and your trainer.  This helps us target troublesome areas and work on them from a training and therapy perspective.  We have had great results from this kind of team work.  Together, we work with the whole team (patient included) to set achievable goals so patients can take control of their health and well-being.  Patients heal faster and stronger.

Specializing in Parkinson’s disease, Taylor combines evidence-based practices with compassionate support, tailoring interventions to each individual’s needs. Her commitment to holistic health and personalized care makes a meaningful difference in her patients’ lives.

In her free time, she loves hiking trails, caring for her cherished houseplants, spending quality time with friends and family, and embarking on adventures with her sweet pup, Ellie.


In October of 2012, the World Health Organization made video called “I had a black dog, his name was depression.”  It is a video version of the 2005 book I Had a Black Dog​ by Matthew Johnstone.  

The instant I saw this video, I realized that my pain had a name, it wasn’t my fault, and it could be treated.

Please contact me if you are struggling with depression.  

I have been in the deep, dark “No One Cares” mode. I still go there occasionally but now I know that there is a way out.