Our Team 


Ross Armstrong

Owner + Programming + CrossFit Instructor

Ross competed in track throughout college at Boise State. After collegiate running, his desire to compete and stay healthy never diminished. He used his knowledge and experience from college athletics to teach himself CrossFit in his garage gym. He noticed that he was in better shape,stronger, and healthier than he had ever been. That led him to get his L1 in 2014 and pursue coaching and helping others get fit and healthy through CrossFit. His passion is helping others and helping them find and work towards their best self. He is a full time critical care respiratory therapist and is CPR/BLS and ACLS certified.


Ben O'Connor

Head CrossFit Instructor + Weightlifting Coach

Ben has been coaching CrossFit professionally since 2011 when he got his CrossFit Level 1 and underwent a 90 hour apprenticeship at his first box in Colorado which included over 40 hours under one of the premier weightlifting coaches in the state. Weightlifting technique was viewed as imperative to success in Ben’s early days of CrossFit and is a specialty of his when it comes to coaching. Ben grew up playing competitive soccer and found a love for physical training during off-season workouts to improve performance on the field. After finding CrossFit in 2008, Ben has been passionate about it ever since.  Ben graduated from Boise State University in 2015 with a Bachelor’s degree in exercise science and received his CrossFit Level 2 in 2016. He loves coaching athletes of all ability levels and helping make CrossFit accessible to anyone.

Contact Ben for details on Personal Training.


Dave Chorpenning

CrossFit Instructor

Dave discovered a passion for functional fitness upon joining the military in 2012. He serves as a Survival Instructor in the US Air Force, conducting experiential training for service members around the world. He fell in love with the CrossFit community while deployed in 2017. He joined CrossFit Composure shortly after moving to Boise in 2018. As an avid outdoorsman, Dave uses CrossFit to stay healthy and competitive in climbing mountains, obstacle course racing, and other wilderness challenges.


Bobby Marturello

Owner + Operations + CrossFit Instructor

Bobby was born and raised in Boise Idaho. Attending Boise State university he earned a bachelor of science degree in mechanical engineering. He was first introduced to CrossFit in 2008 while doing an internship in Huntsville Alabama. He competed in CrossFit Regionals in 2012 and 2013. Going from a pre CrossFit body weight of 135 pounds to 190 pounds has truly has been a life changing experience for him. He loves to help others do the same by achieving their fitness goals, whatever they may be.


Molly Tevis RDN, LD

Nutrition + Meal Planning

Molly is passionate about nutrition and wellness. She is a graduate of Texas Christian University and a Registered Dietitian practicing here in the Treasure Valley.  She believes  there is not a 'one size fits all' approach to health and that good food should be enjoyed.  Molly is actively involved in the community and was awarded the Idaho Recognized Young Dietitian of 2016 from the Academy of Nutrition and Dietetics. She has several years of experience supporting patients with their weight loss journeys or improving various medical conditions through nutrition and lifestyle.  Licensed by the Idaho Board of Medicine and a member of various Academy Dietetic Practice Groups, Molly remains up to date on the most current evidence based nutrition interventions. Her interests include weight management, sports nutrition, and using food as medicine.

Contact Molly for details on Nutrition Consultation.


Spencer Gerke

Owner + CrossFit Instructor + Weightlifting Coach

Spencer played football for 6 years as an offensive lineman at Boise State. After his football career, Spencer dedicated himself to losing weight and lost 70 pounds with the help of CrossFit. Spencer loves fitness and staying active, and competed at CrossFit regionals in 2016. Spencer has a Master's degree in Criminal Justice and has worked at Saint Alphonsus as a manager and laboratory outreach representative for 4 years.


Lyndsy Kinghorn

CrossFit Instructor

I grew up an athlete playing just about every sport. Oddly enough, I was introduced to weight lifting as a cheerleader. Fast forward to college, I worked part time at a local gym personal training, teaching group classes and fell in love with not only what fitness could do for me but how I could help so many people through fitness. I joined the Crossfit community in 2014 after being persuaded by a good friend and training partners. My very first class was the most exciting, yet hardest and humbling thing I had ever done. However, I had “drank the koolaide” and was instantly hooked. CrossFit has changed my life. It has changed the way I view my body and as a woman, we all know that is constant struggle. It has shown me, just when you think you aren’t capable of more, you are and you do things you never thought possible. It has grown me physically and mentally but most importantly what CrossFit has done for me is open my eyes to an amazing community of like minded people, all out to improve their health and wellness, while encouraging one another to the be the best they can be.


Tristan Sluder

Owner + Media + CrossFit Instructor

Tristan is a Boise native who grew up playing competitive hockey and enjoying all the outdoor activities that Idaho has to offer.  He started doing CrossFit in 2011 as a way to train for 'The GORUCK Challenge'.  After multiple challenges his love for CrossFit remained.  He went from 130 pounds to 160 pounds with the help of CrossFit and plant-based nutrition.  He loves helping others achieve their fitness and life goals, whether it's inside or outside of the gym.


Rachel Hamilton

CrossFit Instructor

Rachel is the former co-owner of CrossFit Alaska and has been doing Crossfit and coaching since 2008. She is a 4-time regional athlete and has always loved competition. However, after the birth of her daughter, Maya, her focus has changed to just staying fit and healthy for the rest of her life. She and her family moved to Boise in August of 2017 from Alaska where she grew up and attended the University of Alaska, Anchorage. She is now the owner of Athletic Attic, a high-end athletic wear consignment store in southeast Boise and enjoys being able to continue to coach and help others reach their health and fitness goals.