8th Day Performance was founded by two lifelong dedicated athletes and coaches. Both of whom understand the need for quality training equipment. With their unique backgrounds in athletic ability, coaching, and business, 8th Day Performance products have been tailored to the highest functional standards possible.


Joe Cebulski is a co-owner of 8th Day Performance as well as 8th Day Gym, a successful Crossfit gym in Grand Rapids, Michigan.  As an athlete, Joe won a national collegiate championship in the Decathlon.  He went on to train with, and under, some of the greatest athletes and coaches in the world.  He spent time at the Olympic Training Center undergoing biomechanical and physiological testing by some of the great minds in the field.  These efforts culminated in competing at the 2004, and 2008 US Olympic Trials in Eugene, Oregon.  

Along the way, Joe was fortunate to have spent time training with coach Dan Pfaff, earning a theoretical “PhD” in performance physiology and kinesiology from the legendary coach. 

His experiences as athlete, coach, and gym owner have led to the launch of performance products that solve the needs of each.  

Gregg Richardson is co-owner of 8th Day Performance.  He has had a successful career as a CFO, consultant and business owner since earning his MBA from the University of Michgan. Gregg played Division I baseball many years ago and has been an avid Crossfitter since 2009.

Away from work, Gregg enjoys spending time with his family and coaching youth football and baseball.  He also serves on the Board of the area Youth Football League.