YOUR TEAM

We are passionate about exceeding the industry standard of professional, effective, high-quality training.


Facilitative coaching entails cultivating each athlete’s knowledge of self. Every session is a single step into a broader macro training vision, and athletes grasping this context is what makes our approach successful. Just like our athletes, we come ready to put in work —humbled and inspired that there is always more work to do to help our athletes become fitter.


  • Amy Kosaki

    Co-Owner, Head Coach

    CF L2 / NASM PTC 2022 / NASM CNC 2022

    I believe in a holistic approach to fitness and wellness. I started my professional journey in health and fitness in 2013. As a coach I strive to provide accessible fitness to all skill levels and abilities. In a group setting or in personal training sessions I help athletes set realistic goals and task oriented objectives to establish healthy manageable routines that evolve into lifestyle habits.

    Out of the gym I enjoy playing soccer, soaking up the sun, playing in the outdoors, and spending time with my husband and our 4 children. Coaching allows me to share health & functional fitness with others. I absolutely love coaching and making a positive impact on others’ lives! I am passionate about and dedicated to motivating, encouraging, & educating athletes. My favorite aspects of Tectonic are the community atmosphere & watching others achieve things that they never imagined were possible.

    I look forward to seeing you in class!

  • Yanni Fassilis

    Coach & Teens Coach

    I’ve been surrounded by fitness since a very young age. As an athlete in my early teens, I became fascinated and my passion hasn’t wavered since. As a coach, I love forming new relationships and being a stepping stone to help others reach their goals. Fitness has made a profound impact on my life as a young adult. Through the Tectonic community, I get the unique opportunity to help people reap the same physical and mental health benefits of strength training through both personal and group sessions.

  • Erica Stupfel

    Teens Coach/FYR Tectonic President

    CF L1 2017 & 2023 / CrossFit Kids Trainer / SafeSport Trained

    I have been an avid gym goer since 2011. I love the varied movements, the excitement of seeing my fellow athletes reach new goals and most of all the incredible community and the laughter. I have a passion for teens and providing equitable fitness opportunities for our community. In 2017, with the help of my best friends, we started a non-profit called FYR Tectonic that offers free strength and conditioning style classes for teens in need of a little extra support. We are still functioning with the same passion and model but under the name FYR Tectonic.

    I love the support from this beautiful community… both in my personal life and for our youth.

  • Damen Hermens

    Teens Coach

    CF L1 - 2024

    Middle School Teacher

    Masters in Teaching, Washington State University - 2003

    Education Administrative Certificate, Washington State University - 2013

    Bachelors in Psychology, Washington State University - 2000

    I've been part of the Tectonic family since 2018, when I was introduced to Tectonic Strength and Conditioning. You'll see me in the gym as a youth FYR coach and as a participant at the adult classes. When I'm not in the gym, you'll see me outside and with my kids, loving life. In college I was a competitive archer for Shoreline Community College where kinesthetic awareness and conditioning were important aspects of my training. A few years later, I mentored and directed at youth camps, then began my career as a middle school teacher. I've never looked back since. Working with teens is my passion and my energy. I'm excited to be part of the FYR coaching team.

    I look forward to seeing you at the gym.

  • Damon Kosaki

    Damon Kosaki

    Coach

    CF L1 2014

    I don’t coach many hours on the floor, but you will see me in classes! Here are some tips for your journey.

    -Build character through fitness. Who doesn’t want to be a better person in and out of the gym? I believe what we do at Tectonic is a shortcut to becoming an outstanding human being with physical and mental fortitude. You will be an asset to your community.

    -Enjoy the process! In the Tectonic environment, you will be primed to see results. But let the journey be the thing that you keeps you coming in. Not to mention the relationships you will make along the way! Having this long term mindset will keep you safe and prevent injuries or burnout.

  • Guest coach

    Alex Trehan

    Guest Coach

    CSCS / CF L3

    Welcome Guest Coach Alex Trahan!

    Follow on Instagram

  • Greg Whelan

    Coach, Co-owner

    CF L1

    Bates College, NCAA Track & Field, MBA, Entrepreneurship & Marketing, McCombs School of Business at the University of Texas at Austin - 2013

  • Gabriel Tungol

    Remote Programmer / Co-Owner

    Certified CrossFit Trainer (CCFT) / CrossFit Level 3 Trainer (CF-L3) - 2019 [CrossFit Level 1 - 2013]

    Certified Strength & Conditioning Specialist (CSCS) | National Strength & Conditioning Association - 2016

    L1 Sports Performance / Strength & Conditioning Coach | USA Weightlifting (United States Olympic Committee) - 2015

    CrossFit Specialty Course: Aerobic Capacity Trainer - 2018

    Adult & Pediatric First Aid + CPR + AED Certified - 2019

    Freestyle Connection Movement Seminar - 2013

    Master of Public Health, Johns Hopkins University Bloomberg School of Public Health - 2012

    Bachelor of Science in Neuroscience, Bates College - 2006

    Coach Gabriel now provides programming and expertise from afar in his new wonderful home in Atlanta.

Interested in coaching?

We are always looking for qualified, passionate and driven coaches. Please email us your resume and be sure to share why you think you would be a good fit for our team.