Meet Our Coaches

We want to take a moment to write about the Crossfit Proven 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.


  • Matt Chambers

    Founder, Matthew Chambers has over 18 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 for the past 10 years. Matt has been the Head Coach at a successful CrossFit for over seven years in which he has taken teams three years in a row to the “Reebok CrossFit Games Regional” and has taken a “Masters Level” athlete to the “2011 Reebok 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!

    CrossFit Level 1 Trainer



  • Brittany Yilmaz

    Brittany Yilmaz

    Co-Owner, Brittany Yilmaz 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 at CrossFit Proven. CrossFit quickly captured Britt's heart and she attained her CrossFit Level 1 Trainer certificate one year after starting CrossFit. Britt strives to share all aspects of CrossFit Proven with those she encounters in hopes of helping members achieve their goals and find the fulfillment offered at Proven. 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 Training clients, training and spending time with her family and friends.

    CrossFit Level 1 Trainer


    Eat To Perform Certified Coach

  • Mike King

      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 if 2012 and his Olympic Lifting Certificate in November 2013. Outside of the box Mike is first and foremost a husband to Mindy and a father to Daniel and Hannah. He makes his living as a Six Sigma Master Black Belt/Manager at Vanguard. 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.


    CrossFit Level 1 Trainer

    CrossFit Olympic Lifting Trainer

  • Win Kluth

    Win Kluth

    Win has a lifetime of experience in sports. He started playing baseball at the age of 6 and then picked up basketball at the age of 10. He continued to play baseball and basketball competitively throughout high school for multiple teams. Win graduated from St. John’s University with a BS in Finance. After he graduated, he continually looked for ways to stay fit. Whether it was exercising at a gym, swimming, playing basketball recreationally, or even playing tennis or golf, Win loves to keep active. When Win found CrossFit, he realized it would be his new addiction. “It was love at first WOD for me.” And it’s been his passion ever since. He loves the CrossFit community and enjoys teaching others all aspects of the CrossFit culture.

    CrossFit Level 1 Trainer

  • Mike Johnson

    Mike Johnson

    Mike 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, Mike is an accountant by day, and lives in Exton with his wife, Teri. They are expecting their first child this June.

    CrossFit Level 1 Trainer

  • Chris Lebresco

    Chris Lebresco

    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.

    CrossFit Level 1 Trainer

  • Becky Coots-Kimbley

    Becky Coots-Kimbley

    Becky has always been active in sports and fitness and has always had a passion for helping others. She began her CrossFit journey in January of 2013 and was certified as a CF-L1 Trainer in October 2015. Becky graduated from Alvernia University in 1997 with her PTA degree and in 2001 received her personal training certificate. Then, in 2005 after graduating from Pennsylvania school of muscle therapy, Becky also became a licensed massage therapist. Here she has been able to combine two passions into a specialized niche, CrossFit and rehab of the CrossFit athlete. Becky continues to practice massage out of her Exton office when she isn't training or coaching others to be their best.

    CF-L1 trainer

  • Brian Parks

    Brian Parks

    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.


  • Ethan M Farkas

    Ethan M Farkas

    Ethan began powerlifting at 17, and continued to do so for three years. While powerlifting Ethan took 1st at USAPL High School Nationals 2011, and competed in the RAW Challenge and the Arnold Sports Festival (USAPL). An unfortunate injury forced Ethan to rethink his approach to fitness and reconsider how he would approach it. Local Strongman competitions peaked his interest. In October 2012, he competed in his first Strongman show, placing 2nd at Delaware's Strongest man. Since his first show, he's competed in eight shows to date including NAS Nationals (placing 11th overall and 3rd in the 300# weight class) and the Amateur World Strongman Championships.

    Strongman is similar to crossfit, its a tough sport physically and mentally. Its the one thing in this chaotic world that's constant and truly rewards you for the work you put into it. Ethan's mission is to spread the strongman gospel to the masses and to get as many people involved as possible.

    Currently, Ethan is a senior at West Chester University seeking a Bachelor's of Science Degree in Exercise Science and continually working to move up the ranks in amateur strongman until the day he earns Professional status.

  • Don Simcox

    Don Simcox

    Don has spent his life in sports. After playing football for four years at Widener University, and coaching for an additional two at Rutgers, a D1 university, he searched to scratch that competitive itch in him. After brief training stints in powerlifting, strongman and general fitness, Don found a home in Olympic weightlifting.

    He has coached and assisted in the sport for the last four years. With his varied past, he is able to bring a multi-view perspective to the sport that sometimes can be very rigid. With this perspective he is able to adjust programming volume and scheduling to fit anyone from the everyday Crossfitter looking to improve their lifts, to the athlete looking for the last piece to become elite, or to the competitive Olympic weightlifter looking to stand on the podium. Don spends his free time with his family and watching football. E-A-G-L-E-S, EAGLESSS

  • Derek Wakefoose

    Derek Wakefoose

    Derek’s athletic career began at age 10 with soccer and baseball. Within the year, he realized he held a passion for all athletics. Over the next few years Derek participated in soccer, wrestling, lacrosse, baseball, and football, excelling in anything to which he commits. In 2008, Derek began his CrossFit and Olympic lifting journey. He devoted all of his time and energy into developing his gymnastics and Olympic lifting. In the following years, Derek qualified two times for junior nationals in Olympic lifting. At 18, he received his CrossFit Level 1 Certification and immediately began assistant coaching. Since 2014, Derek has been coaching in both group and personal settings. Eight years of personal experience, combined with an extensive athletic background, has allowed Derek to help many people of all ages. With Derek’s help, these people have been able to find success in their health and fitness goals. Outside of the gym you can find Derek climbing trees, reading, learning and spending time with friends. His passion and positive energy brings a welcome addition to the CrossFit Proven staff.

    CF-L1 Trainer 

  • Sierra Farkas

    Sierra first started her fitness journey in October of 2013. She began with Crossfit then transitioned to solely training Strongman. In March of 2014 she competed in her first Strongman competition and was immediately hooked. Since then she has competed at Nationals 3 times, placing 2nd at 2016 Nationals, and has qualified for Worlds twice. She has also won 2 state titles, becoming Delaware's and Pennsylvania's Strongest Woman of 2017. Sierra is passionate about being strong, not only physically but mentally and spiritually as well. She believes that Strongman has helped strengthen her on every level. Sierra plans to continue competing in hopes of earning her professional status one day. She would like to get more women involved in the sport of Strongman to help them realize their true strength. Sierra plans to pursue a career in law enforcement, she will begin her training in the police academy this winter. Outside of the gym you can find Sierra hiking, kayaking, backpacking and traveling. 

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