Trivia: Sylvester Stallone sustained 14 injuries during filming, including breaking a tooth, rupturing his ankle and getting a hairline fracture in his neck that required the surgical insertion of a metal plate. He even had bronchitis and shingles during the shoot.
Trivia: During the car chase, Dolph Lungren's character is holding the same type of gun that Thomas Jane used in the Punisher, which Dolph did his own version in the 1980's.
Trivia: Wesley Snipes was the first choice for the role of Hale Caesar, but couldn't accept because his tax issues made him unable to leave the United States.
Answer: The back stories of the individual members of the team have never been elaborated upon. It is never stated where the members received training.