BDX is a gym built by trainers for trainers. Our philosophy is simple – trainers are our clients. Our passion is creating an environment built on collaboration, education, and community to fuel and support the trainers who call BDX home.



Our mission at BDX is to assist our community by providing the tools and support to “discover their X”

We believe that health, wellness, and fitness are an art. We’re here to do more than just put you through a cookie-cutter workout. The trainers that call BDX home are here to help you “find your X” so together you can transform your lifestyle and accomplish your goals.

“Art is art and life is life, but to live life artistically; that is the art of life.” – Peter Altenberg


Brad Bose / CEO Co-Owner

Brad Bose, cofounder of BDX, has been committed to the art of “finding your X” for over 30 years. His roster of celebrities and elite athletes reflects his extensive education and expertise.

A graduate of Hope College in Holland, Michigan, Brad studied physiology while playing football and wrestling on a national level. Brad went on to play professional football in Chicago but suffered several injuries that retired him from contact sports. Rehabilitation from these injuries expanded Brad’s knowledge of physiology and passion for training. During this transition, Brad earned an MBA from Webster University in Northbrook, Illinois, and channeled his love of contact sports into competing as a bodybuilder. Brad placed in several local contests including MR. LAKESHORE, MR. CHICAGO and MR. ILLINOIS and was invited to be a consulting member of The President’s Council on Fitness.

Brad relocated from Illinois to Los Angeles and became a pioneer in the private fitness industry, consulting at Gold’s Gym in Venice, CA. Brad has launched and managed several other high-profile private training gyms in Los Angeles, where he has trained a large number of well-known Hollywood celebrities and has worked on various television and film projects…


Christen Seibold / COO Co-Owner

A Colorado native, Christen knew from a young age that she had a passion for teaching and physiology. Thanks to her physical therapist mother, Christen could identify bad gait patterns as a small child and proudly announced she hurt her “patella” when she was 5.

Christen grew up participating in competitive swimming and gymnastics. While her mother taught her the science of the human body, her best coach was her father. He was adept at watching any sport and breaking down the movements into parts allowing the athlete to learn the movement pattern properly and apply it to a sport or everyday life. Christen parlayed the skills she learned from her father into teaching gymnastics at the age of 15 and discovered her gift of teaching and coaching and decided to pursue a career in the health and fitness world.

Christen attended the University of Colorado at Boulder, where she excelled in Anatomy, Neuroscience, Biomechanics and Psychology, and graduated in 2002. Upon graduation Christen started developing her skill set at the Boulder Center for Sports Medicine as a Physical Therapy Aide. There she provided rehabilitative services and utilized her proficiency in organization and scheduling to create a day-to-day procedural handbook for…


Michael Seibold / Co-Owner & Operator

Michael Seibold, a certified trainer and Santa Monica native, helps manage and operate BDX’s Santa Monica facility. Michael also runs Be Bold Fitness, a personal training business, with his wife Christen.


In Memory of
Mark Harigian

Mark Harigian, owner of Harigian Fitness, was a world-renown designer of high-end, custom home gyms. Mark, the “Architect of Anatomy,” consulted with BDX on facility design and assisted in procuring our unique, state-of-the-art fitness equipment.