About Trivium

Welcome to Trivium

We are the leader in integrated performance training, nutrition, and stretching programs for elite athletes and everyday people alike.

 We offer programs and services for professional, amateur, collegiate, high school and youth athletes, as well as business executives and industry professionals.

Trivium was founded in 2016 by Ryan Muir as a refuge from big corporate gyms that lack individually customized programs and a personal community. Ryan developed Trivium with one vision in mind: to create a welcoming facility that encourages and motivates its clients to achieve their health and fitness goals. To achieve this vision, we have built an atmosphere that fosters the individual growth of our clients, not only physically, but mentally as well.

At our gym in Affton, MO, Trivium provides training, nutrition, and stretching programs designed to help shape ourc lients into the healthier, better versions they desire. Our personal specialists focus on your individual needs, and our trainers have been hand-picked for their remarkable ability to improve strength, speed, power, mobility, agility, and weight loss. In short, we specialize in helping clients obtain the tools needed to enjoy healthier lifestyles.

Our goal at Trivium will always remain the same: 

"To teach others the skills needed for not only personal success, but also how to take that knowledge and apply it to their everyday lives."

Keshav R


I was pretty nervous about going to a Personal Trainer because this was my first time hiring a professional. From the moment I walked into Trivium Personal Fitness, I was welcomed with a non-judgemental and friendly attitude....

Kevin Dubbins


Working with Trivium helped me to achieve my goal of gaining weight the correct way. Ryan uses science and physiology in his approach rather than pushing fad exercises/diets and pushing supplements that don't work.

Christian Hatfield

I would highly recommend Trivium to anyone looking for a new gym or personal training. The gym has your standards (weights, racks, benches) but it also has open areas for functional training and classes with the equipment to match. The staff is knowledgeable, and I can attest that Ryan is continually searching out the latest research to incorporate into the gym's offerings. If you're looking to avoid the cookie-cutter gyms and step into an atmosphere dedicated to getting smart, safe results, give Trivium a shot.

Brianna O’Hara

Trivium is the place for me! They offer customizable workout plans based on my needs!

Sam Buckle

Trivium can really change your life as it has done to mine , the knowledge and skill base I’ve required from Ryan is unmatched from any other trainers I’ve worked with he will teach you the why, hows, when’s, and the what’s highly recommend!

Cari Stewart

I have been putting off exercising and weight loss for years, and was scared walking into a gym again. This was nothing like I expected! I've hard health scares recently, and this was a little intimidating at first, but Ryan really knows his stuff, from nutrition to how the body works, to what exercises are going to do the best for me. I am so happy to have overcome my "gym fear."