Why Principia?

Established in 2017, Principia CrossFit is one of the fastest growing CrossFit gyms in Boise and Meridian. In 2019, Principia CrossFit became a finalist in the Best of Treasure Valley, earning Principia CrossFit the title of The Best CrossFit Gym in the Treasure Valley. Our motto, “An Object In Motion…” lays out our goal: we work to help people increase their functional movement so that they can continue to move throughout their lifetime.

Our program focuses on combining strength, cardiovascular endurance, and mobility to help you function at your peak performance every day.  All of the movements in our classes can be scaled to any ability level, meaning anyone can to CrossFit!  Just show up, and we will take care of the rest.  We offer specialized fitness regimes for beginner CrossFit athletes, to competitive CrossFit athletes, and everyone in-between. 

Our coaches are here to ensure our athletes are moving safely and efficiently, while providing encouragement and intensity to every workout.  At Principia CrossFit, we are more than just a gym; we are a community of athletes.  When you come in to workout, you will be greeted by friends who will encourage you and push you to accomplish more than you thought possible. 

Meet Our Coaches

Mitch Iverson

USA Weightlifting Coaching Education – Level 1
CrossFit – Level 2
International Kettlebell and Fitness Federation – Level 1

Mitch Iverson is the owner and head coach at Principia CrossFit. From early adulthood, Mitch has taken a strong interest in the fitness industry. He began his career doing what he calls “Health Conscious Bodybuilding.” He worked as a personal trainer for a few years during which time he earned the Fitness Federation Certification and the International KettleBell Certification. His days personal training ignited his passion for educating his clients in their journeys to better themselves. When Mitch began doing CrossFit in 2013, he quickly became hooked. He earned his CrossFit Level I Certification the next year, and has been coaching ever since.

Mitch has been pursuing his passion in health for over ten years now. He has armed himself with a wealth of knowledge over multiple perspectives, giving him a well-rounded basis for coaching. Mitch believes that fitness is a lifestyle not a quick fix, and there is not ONE path to success. He firmly believes that the gym, and the work you put into it, not only makes you fit as hell, but also teaches many life lessons that can be applied daily.

Learn more about why Mitch started a CrossFit gym on our blog: http://principiacrossfit.com/started-crossfit-gym/

Bria Sommer

CrossFit Level 1
BIRTHFIT Boise Co-Regional Director

My start into athletics began when I was 9 when my dad signed my sister and I up
for Taekwon do. It started as a way for us to stay busy after school and eventually
developed into a competitive sport for me. I competed and medaled at a world level
twice, and received my 3 rd degree black belt before graduating high school.

After high school I began managing a fitness facility on an Army base (where I met
my husband!) and that’s when I was first exposed to Crossfit and began doing
“Crossfit inspired” workouts on my own during my lunch breaks. The work outs
were fast, full body, and gave me the intensity that I was craving after I had been a
competitive athlete for years. When my husband deployed I joined my first Box and
it was the community that really made Crossfit something I knew I would do

I have a special interest in helping pregnant and postpartum athletes find what
works for them and ensuring that they can continue doing what they love after baby,
having experienced this myself through 2 pregnancies. The uniqueness of each
athlete is especially true during this vulnerable time in a woman’s life where
circumstances are so individual and a customized approach is crucial.

What I love most about CrossFit is that it’s for everyone, every body, and every life
stage. It makes us resilient, strong, and gives us genuine connections. I’m excited to
be a part of Principia’s family and look forward to growing, learning, and being
better everyday with all of you!

Kevin Sommer

CF level 1 (2010)
CF level 1 (2014)
CF Powerlifting (2012)
CF level 2 (2014)
CF Mobility (2015)
CF Rowing (2015)
CF Endurance (2015)
CF Gymnastics (2015)
CF Weightlifting (2015)

I started CrossFit in 2008 while serving in the ARMY, and I was hooked from the first workout as it was everything I loved about fitness, Weightlifting, conditioning, and fundamental gymnastics performed at high intensity. CrossFit gave me the fighting edge I needed to do my job well as a sniper in Iraq and Afghanistan, and soon became a staple for others to follow. Currently I am a student at Boise State studying physics with an emphasis in astrophysics. I am proof that CrossFit is for everybody regardless of physical limitations, prior injuries, and various backgrounds, but it is important to be patient and mindful of those limitations so that we can reach tremendous goals together!

Jonathan Sorenson

Bachelors of Science in Health
CrossFit Level 1

I always lived an athletic life growing up. I played varsity football and basketball and loved sports. After high school I received an appointment to study at the United States Military Academy. When I left the Army I fell into a period of unhealthy eating followed by no exercise or movement. Before the knew it I was close to 50-60 pounds heavier than when I left the Army.

Years went by and I was unhappy and unhealthy. I started my crossfit journey in 2016 and received my L1 in Jan of 2018. Crossfit has given me my life back. I am in the best shape of my life, down to my fighting weight and able to do more than I ever thought.

In 2017 I graduated with my Bachelors of Science in Health and have aspirations of attending graduate school in the near future. I have a passion for helping others and truly love what Crossfit has done for me and want others to experience the same success!

Meet Our Coaches

Mitch Iverson

Bria Sommer

Jonathan Sorenson

Kevin Sommer


I’m not in very good shape… can I do CrossFit?

Our programing is designed to be scalable to any ability level, which means anyone can do CrossFit.  Whether you are an elite athlete or someone who hasn’t been to the gym in years, you can walk into our gym and get a great workout that will meet you at your level of fitness.  CrossFit is for everyone, regardless of size, shape, or age.  Our members are everyday people that show up to push themselves, cheer on their friends, strengthen their bodies, and live a happier, healthier life.

What will my first time in your gym be like?

If you choose to start with a one-on-one, one of our awesome coaches will give you a tour of the facilities, we’ll sit down with you and discuss your goals, we’ll do a quick fitness assessment with you, and we’ll walk through what you can expect.

If you prefer to drop in on a class first, you’ll need to sign our waiver before jumping in on the action.  After you walk through the doors, you’ll see a place to store your stuff, and if needed, get changed into your workout gear.  When class begins, your coach will start by leading you through a warm-up as a group.  Then, the coach will guide you through the strength or skill session and the WOD (workout of the day).  CrossFit is known for its constantly varied, functional movements, but the coach will always explain and demonstrate the movements and how to scale those movements to your particular needs.

What do I bring?

We provide all the equipment.  Just come in workout gear that you can easily move around in.

What is your drop in policy?

We love nothing more than having visitors from other boxes come “throw down” with us!
If you are just passing through, we charge a drop in fee of $15  per class or offer a ten pack punch pass for $120.

It’d be great if you’d plan on arriving 15 minutes before scheduled class time so we can provide you with a waiver to sign and introduce you to our box.

Will CrossFit make me bulky or lose my gainz?

Many believe that CrossFit will make them lose their gains while others still worry it will make them bulky. In all reality, the program is designed for a fitter you. That means your body is going to go where the fitness takes it.  You will get stronger; you will also shed some fat.  But ultimately, your body will shift to it’s naturally healthiest place.

I have had a previous injury, can I still do CrossFit?

We always recommend you discuss any new workout programs with your physician. That being said, we do find that many of our members have successfully used CrossFit to help rehabilitate from old injuries. We focus on strength and mobility, and always scale movements according to your own limitations. If you do have any injury or limitation, please contact us prior to showing up to class to let your coach know. We encourage you to schedule a one-on-one session prior to you coming to class to go over the specifics of your injury and discuss how we can work through it together.

Principia CrossFit

If you are ready to start making changes and realize your potential, come join us!