Former U.S . Postal Service rider Scott Mercier claims there was a culture of doping . Mercier says he was offered steroids by team doctor Pedro Celaya in 1997 . He also alleges that the riders were given injections to increase their stamina and speed, but they never used them because it would have been too dangerous for them. Former teammates of Lance Armstrong have testified against the famous cyclist .
Former U.S . Postal Service rider Scott Mercier claims there was a culture of doping . Mercier says he was offered steroids by team doctor Pedro Celaya in 1997 . Celeya denies the accusations and will challenge USADA at Court of Arbitration for Sport . Former teammates of Lance Armstrong have testified against the famous cyclist .