Kai began weight lifting at an early age with the encouragement of his teacher. Weightlifting allowed Kai to channel his focus on something positive, because his childhood was a rough one. As Kai explains in his autobiography, he became a ward of the state when he just 6 years old and he went from foster home to foster home. He started winning teen tournaments and then began training at the 5th Avenue Gym in Brooklyn.
Soon Greene sought higher aspirations and wanted to become a professional bodybuilder. In 1999 he entered and won Team Universe, but then disappeared for 5 years only to re-emerge in 2004. Again it was for Team Universe and again Greene won. With a victory secured at Team Universe, Greene was qualified to enter into professional competitions, and he officially went pro in 2005 at the IFBB New York Pro. Greene has a total of seven professional wins.
Bodybuilding Record (Contest History)
2012 IFBB Mr. Olympia 2nd
2012 IFBB Sheru Classic Asian Grand Prix Pro Bodybuilding & Figure 3rd
2011 IFBB Olympia 3rd
2011 IFBB New York Pro Bodybuilding, Figure & Bikini Championships 1st
2010 IFBB Olympia 7th
2010 NPC Long Island NP
2010 NPC Rhode Island NP
2010 NPC Pittsburgh NP
2010 IFBB Australia Pro Grand Prix X 1st
2010 IFBB Arnold Classic, Ms International, Fitness International & Figure International 1st