Greg Anderson is the personal trainer and a boyhood friend of baseball star Barry Bonds. He is alleged to have supplied Bonds with anabolic steroids and human growth hormone.Seattle Post-Intelligencer: Barry Bonds: Anatomy of a scandal (December 25, 2003)

In Bonds' 2003 grand jury hearing, Anderson refused to testify about Bonds' steroid use; he eventually spent 13 months in jail on contempt of court charges.USA Today: Barry Bonds' personal trainer ordered to court (February 23, 2009) ESPN: Bonds trainer to be called to testify (February 14, 2009) Anderson was subpoenaed to appear in court on February 25, 2009, to state whether he intends to appear in Bonds' upcoming perjury trial. His attorneys have said Anderson will refuse to testify.USA Today: Barry Bonds' personal trainer ordered to court (February 23, 2009)

Anderson was a team captain of his college baseball team at Fort Hays State in Kansas who could swing a bat but wasn't fast enough to make it in the minor leagues. After college he returned to California and began a personal training company called "Get Big Productions", building connections with BALCO, a laboratory in Burlingame, California that has been accused of producing steroids.Los Angeles Times: Trainer Is Still Silent Partner (August 13, 2006)

Anderson had met Barry Bonds as a child and, in the late nineties, he reconnected with Bonds, becoming his personal trainer.San Francisco Chronicle: 40 of 42 BALCO charges dropped (July 16, 2005)

In 2003, federal agents alleged that Anderson was supplying athletes with steroids. Anderson's home and BALCO were raided and a doping calendar with Bonds' name was among the items confiscated. Anderson and BALCO owners Victor Conte and James Valente, and track coach Remi Korchemny were all indicted.San Francisco Chronicle: 40 of 42 BALCO charges dropped (July 16, 2005)

A plea agreement dropped most of the counts, and allowed Anderson and the others to plead guilty and serve relatively brief prison sentences. None of the defendants were required to provide names of steroid-using athletes.San Francisco Chronicle: 40 of 42 BALCO charges dropped (July 16, 2005) Anderson pleaded guilty to distribution of steroids and money laundering and served a six month sentence.Los Angeles Times: Trainer Is Still Silent Partner (August 13, 2006)

In 2003 grand jury testimony, six baseball players admitted receiving steroids from Anderson: Jason Giambi, Jeremy Giambi, Benito Santiago, Armando Rios and Bobby Estalella. Two others—Barry Bonds and Gary Sheffield—said they had received substances from Anderson but believed the substances were legal.San Francisco Chronicle: 40 of 42 BALCO charges dropped (July 16, 2005) Anderson refused to say whether he gave Bonds steroids and spent 13 months in jail.ESPN: Greg Anderson held in contempt, returned to jail (August 29, 2006)

In 2009, Barry Bonds will be tried on grand jury perjury charges. The judge in the case has said prosecutors cannot use evidence such as the doping calendar discovered in Anderson's house in the 2003 raid, unless Anderson authenticates the documents. Anderson is expected to refuse to testify.New York Times: Prosecutors May Appeal in Bonds’s Perjury Case (February 20, 2009)