Colorado Springs, CO (My Sportsbook) - American cyclist Tyler Hamilton has accepted an eight-year suspension for testing positive for a banned substance, the United States Anti-Doping Agency announced Tuesday.

USADA said in a release that the 38-year-old Hamilton had tested positive for testosterone or its precursors in a sample taken February 9 of this year. It is Hamilton's second offense, and the release said Hamilton agreed to the lab findings that resulted in the ban, which started provisionally on March 17.

In April, Hamilton admitted to taking an over-the-counter anti-depressant supplement with the knowledge it contained a banned substance, and announced his retirement.

"In the sport of cycling, eight years ineligibility for a 38-year old athlete is effectively a lifetime ban, and an assurance that he is penalized for what would have been the remainder of his competitive cycling career," said Travis T. Tygart, USADA CEO.

Hamilton had already served a two-year suspension handed down in April 2005 by USADA.

That was after he won the gold medal in the men's individual time trial at the 2004 Summer Olympics in Athens, but failed a blood doping test after the Games. Hamilton was allowed to keep his medal because there were no results from the backup sample due to improper storage.