A mixed-martial arts (MMA) trainer testified for the defense on Monday that George Zimmerman "didn’t know how to really effectively punch" even though he had trained the former neighborhood watchmen for over a year.

"He was just physically soft," Adam Pollock told the court. "He was an overweight, large man when he came to us, and very pleasant -- a very nice man, but physically soft. He was predominately fat, not a lot of muscle, not a lot of strength."

Under cross-examination, Pollock admitted that Zimmerman could have lost as much as 80 pounds and had a body mass index as low as 16 percent at the time that he shot and killed 17-year-old Trayvon Martin.

Watch this video from CNN, broadcast July 8, 2013.