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Meet Our Coaches

We want to take a moment to write about the Proven Fitness coaching staff. We believe that coaching is critical to your experience and is something that differentiates Proven. Anyone can become a Crossfit coach by meeting all the requirements of a Level 1 Certification seminar. That certificate is only the foundation for our coaches at Proven. We strive to hold our coaches to a higher standard. Each member of the staff is chosen for their ability to engage with athletes of all levels, their ability to teach athletes to perform movements safely, their enthusiasm for building the Proven community, and their passion for learning and building their own technical expertise.

Each of our Coaches have come up through the ranks as members of CrossFit Proven. Most of our coaches have been learning exclusively from at Proven for 1 to 3 years. They’ve become proficient in our exclusive techniques that have brought success to all of our athletes. This experience is invaluable and is the key ingredient in the application of our coaching techniques. Our coaches engage in continuing education through regular clinics at CrossFit Proven. These clinics focus on the development of their technical expertise. Each coach goes through an inclusive and intensive apprenticeship under the direct tutelage of Matt and each have demonstrated a complete proficiency and efficacy as a coach before they are able to lead classes at CrossFit Proven. Our coaching staff also participates in seminars and receives certifications outside of Proven’s in-house program like; CrossFit’s Olympic Lifting Certification and CrossFit Mobility.

Our staff has a commitment to excellence and constant learning. Proven coaches will always put the needs of Proven athletes first when we are at the box. We know that one thing you ask of us and the other coaches is to give you the best effort we have everyday and ensure you have the best experience possible. We pledge to you, our members and our staff, that we will strive everyday to deliver that best possible experience. Exceptionalism is our standard. Below, you can read brief bios on each of the Proven coaches.

Thank you for making Proven the best place to be a coach.

Matthew Chambers

CrossFit Level 2 Trainer | CMT

Co-Owner, Matthew Chambers has over 20 years experience working as a professional Strength and Conditioning Coach. Professional athletes, homemakers, seniors and children alike have seen great success working with Matt; and you will too! Coach Matt has developed hundreds of coaches all over the world working as an instructor at the National Personal Training Institute since 2004. Matt has been a CrossFit Affiliate owner since 2007. Through that time he’s helped teams and individuals make it to the CrossFit Games Regional four times including a trip to the CrossFit Games. When Matt isn’t coaching he spends time with his family, whom you will also find at the box on a regular basis!

Brittany YC

CrossFit Level 1 Trainer | MSW, LSW, CCTP
Eat To Perform Certified Nutrition Advisor

Co-Owner, Brittany Yilmaz-Chambers has always had a passion for community and connecting with others. Pursuing this passion first through volunteer work, then yoga and cross training during her college career, and later professionally as a social worker, Britt discovered that she could also fulfill that passion with health and wellness. CrossFit quickly captured Britt’s heart and she attained her CrossFit Level 1 Trainer certificate one year after starting CrossFit in 2013. Britt strives to share all aspects of wellness with those she encounters in hopes of helping members achieve their goals and find the fulfillment offered at Proven Fitness. With a dedication to holistic healing, clean eating and connecting with the power of God and self, Britt believes fitness is much more than exercise. When Britt’s not coaching, you can find her working with her nutrition and therapy clients, training and spending time with her family and friends.

Mike King

CrossFit Level 1 Trainer | CrossFit Olympic Lifting Trainer

After years of destroying his knees playing basketball and volleyball Mike King was inspired to try CrossFit in April of 2010. He hasn’t looked back since and now you can find the entire King family at the box. Mike received his Level 1 Trainer Certificate in September in 2012 and again in 2017. Outside of the box Mike is first and foremost a husband to Mindy and a father to Daniel and Hannah. Mike’s goals as a coach are to ensure Proven athletes have fun (safely), achieve their goals, and embody the CrossFit spirit of virtuosity. Ask him about that.

Chris Lebresco

CrossFit Level 1 Trainer

Chris is one of many CrossFit Proven success stories. Back in April of 2013, Chris came to Proven overweight and out of shape. After only 8 months of dedication to CrossFit along with a healthy diet, Chris was able to shed 50lbs and become stronger and healthier than ever before. During this transformation, Chris’ passion for CrossFit grew and now as a coach he is looking to help others reach their fitness goals. Chris enjoys staying active by running, biking and swimming and frequently competes locally in 5k runs, bike races, triathlons and CrossFit competitions. He also plays basketball, deck hockey and tennis whenever he gets a chance. Chris’ goal as a CrossFit Trainer is to help CrossFit Proven members take their athletic abilities to the next level and to see members constantly improving. When Chris isn’t coaching or working out, you can find him taking care of his two children Nick and Brooke and trying to keep up with his CrossFit wife, Lindsay. You may also run into Chris out at your favorite bar or restaurant where he regularly performs as a solo acoustic act throughout the Philadelphia area.

Mike Johnson – “MJ”

CrossFit Level 1 Trainer

MJ has always been active in sports and recreation; from baseball to football and long distance backpacking since the age of 7. He signed himself up (as well as his wife, without her knowledge) at Proven the day after returning home from his honeymoon in June of 2012 and hasn’t slowed down since. The decision to coach at Proven was easy as he gained great knowledge and respect from the sport of CrossFit and sharing that with others is very rewarding to him. A graduate from the University of Pittsburgh with an MBA from Texas A&M, MJ is an accounting manager by day, and lives in Exton with his wife and daughters.

Brian Parks

CrossFit Level 1 Trainer

Brian has been passionate about fitness for over 30 years, including gym memberships, running, adventure racing, golf and other outdoor activities. He is also an avid woodworker and gardener. He found CrossFit through friends in 2011 and was instantly addicted to the workouts, the atmosphere and the community. Brian has a passion for teaching others and is motivated by helping other athletes excel at all aspects of CrossFit. When not at the box, Brian enjoys spending time with his family and can be found watching his daughters compete in equestrian events and field hockey.

Coach V – Head Personal Trainer


Coach V has been in the fitness industry for the last 14 years. He is a former obese class II individual that started playing sports at a very early age and never stopped since. He obtained his bachelors and masters degrees in Human Physiology while playing D-1 college football and has been successfully working with athletes at the amateur, collegiate, and semi-pro levels in North America and Europe. He specializes in Strength & Conditioning, behavior/lifestyle modification, and weight loss. When he isn’t coaching or working out at the gym, you can find V spending time with his wife.

TJ Demetrio

CrossFit Level 1 Trainer

TJ started at CrossFit Fidelity after moving home from college and having his mom, Lisa, also a PF Boyertown member, convince him to do Murph with her. After TJ got destroyed by the work out, he realized how out of shape he was and knew his only solution was to join CrossFit! TJ is someone that loves to share his knowledge with others. Coming from a diverse athletic background including football and wrestling, he understands how fitness and health is important when it comes to performance. Over the past four years, TJ has developed a strong passion for CrossFit and hopes that he can coach others to reach their fitness goals! TJ has also been an employee at Vanguard for the last three years and just bought his very first home which has kept him busy with renovations. He enjoys playing guitar, his favorite video game is Tony Hawk’s Pro Skater, and he loves the New York Giants.

Jeff Shontz

CrossFit Level 1 Trainer

Jeff joined CrossFit Fidelity in September of 2019 and immediately fell in love. After spending prior years focusing on strength training in the fall/winter and running in the spring/summer, he found his overall fitness would fluctuate. CrossFit has provided the perfect balance across strength and conditioning. He is now a frequent 5:30amCrossFitter and received his CrossFit Level 1 in December of 2020. He is looking forward to coaching classes and helping others achieve their goals. Outside of CrossFit, Jeff has participated in many 5k races since 2013, which included 15 5k races from June 2018 – July 2019. One of his favorite running memories is when he ran in the 2014 Philadelphia marathon, while his mom ran the half marathon. In the fall of 2017, Jeff and his wife, Jena, signed up to be the Community Coordinators for the Healthy Kids Running Series here in Boyertown, which averages almost 200 kids, ages 2 – 18, participating in the spring and fall race series. Jeff is a board member for Boyertown Area Multi Service and is a part of their Wellness Committee, which helps to promote wellness programs throughout the Boyertown area; this includes the annual Wellness Fair and Turkey Trot. Jeff strives to lead by example, not just for his daughter and son, but for everything he does. He believes that if you work hard, good things will happen!

Ben Searles

In 2018, after making some lifestyle changes, I was diagnosed with type 2 diabetes out of the blue.  In the next three months, I had gained over 90 pounds and found myself out of breath after just tying my shoes.  Not to mention my glucose numbers were in the 375 – 400 range, where my goal would be between 100-150 range.  After modifying my medicines (insulin), my primary care physician and endocrinologist suggested I start a workout regimen.  I knew exactly who to call, Proven Fitness. My first day was not what I expected at all.  Much more intense and overwhelming.  Coach Matt reassured me that the exercises could be scaled down to my comfort and the class was so welcoming I knew I found the right spot. When I went home after my first class, I checked my glucose number, and it was 126!  I will never forget that number.  I have been hooked ever since and jumped at the chance to coach! Outside of coaching, my interests include the holistic lifestyle, nature, and spending time with my family. I have been athletic to some capacity all of my life but with no real discipline. “Work out with intention!”  “Don’t cheat yourself, treat yourself!”