Iron Core was born in October 2004 when Sarah Lurie saw something others didn’t—the untapped potential of kettlebell training beyond the domain of burly muscle men. In La Jolla, she built something revolutionary: a training philosophy rooted in precision, longevity, and meeting people exactly where they are. Through clever marketing and an undeniable media presence, she transformed an obscure strength modality into a movement.
I joined Sarah in late 2007, and for three years, I learned what it meant to train with purpose. Even after that chapter closed in 2010, the philosophy never left me. I carried it forward under my own brand—Grinds and Ballistics—named for the two fundamental movement patterns that define kettlebell training.
In 2018, I launched a modest operation in City Heights. When I reached out to Sarah, she did something I’ll never forget: she entrusted me with the Iron Core name and legacy. Not as a gift, but as a responsibility. Iron Core became the brand. The Iron Core Way (ICW) became the philosophy. And the Four Chambers became the system that would guide every client’s journey.
The Iron Core Way isn’t about quick fixes. It’s about our long-standing principles.
StrongFirst Senior Instructor
Os has been in the fitness industry since 2005. He has a Master’s degree in kinesiology with a concentration in biomechanics from Point Loma Nazarene University. He is a Certified Strength and Conditioning Specialist (CSCS) through the NSCA, a StrongFirst Senior Instructor, and Z-Health Movement Specialist. Os’ Z-Health education includes Exercise Therapy, Movement Re-education, and Movement Integration. He is a lifelong martial artist and former modern dancer, having performed for Mojalet Dance Collective for three years. He is a proud San Diego State University Aztec and U.S. Army veteran.
StrongFirst ELITE INSTRUCTOR
A local to San Diego, Erica Buechner has been into all things physical since she was a kid. A professional dancer since 1999, she began her journey with kettlebells in 2006 when she met Os Aponte. Since then, she has become a StrongFirst Elite Instructor and Strenth Coach, received her 200-hour yoga certification, and continued to be a dancer, choreographer, and producer in San Diego. Erica attended San Diego State University, where she received her Bachelor of Fine Arts in Dance and obtained her MFA in Dance from Hollins University/American Dance Festival.
